the green house effect article is best given in the blog while i think the different formula given in the blog are unique.

Aim an air molecule straight up, for 288K it falls back at 12 km. Other than straight up, bouncing tops of petal shaped elliptical arcs. I was trying to get on RMS value for velocity, to get temperature.

However, once collisions are introduced, several complications arise. Collisions are neither energy, nor momentum conserving; Storing in vibrations and rotations, emitting and absorbing photons.

Getting complicated, but there are only so many types of gas molecules, and only so many possible collision outcomes.

Steve #266

There is nothing special about 220 K it's just the approximate temperature at 12Km so I don't quite understand Franko's earlier comment that the KE was zero at 12Km (#262) I'm just trying to clarify what he is telling us.

Just out of interest here Kleidon and Lorenz (2005 ; in the 'Red Book') give the following temperatures for the loci of the start and mean heights of various upward heat fluxes and the related heat fluxes and entropy productions:

Latent heating: 288 K -> 266 K; 79 W/m^2; 23 mW/m^2/K

Sensible heating: 288 K -> 280 K; 20.4 W/m^2; 2.1 mW/m^2/K

Frictional heating: 288 K -> 280 K; 1.9 W/m^2; 7 mW/m^2/K

Absorbed/re-radiated SW solar: 252 K -> 255 K; 68 W/m^2; 258 mW/m^2/K

Terrestrial radiated/absorbed: 288 -> 252 K; 47.6 W/m^2; 24 mW/m^2/K

So what is so special about 220K when the Earth's black body T = 255 K?

Franko

What is the ratio of the kinetic energy at 288K to 220K (~12km)

At surface r = 6378137 m T=288K
(3/2)* k*T = 5.964409728e-21 = (m*v^2)/2

m = 48.09584754104e-27 kg (one atom = 28.964*1.66053886*10-27 kg)

Online equation solver
G*M*m*(1/6378137-1/(6378137+12680.983))
= m*G*M/3214381143

From Maple
5.964409781*10^(-21)

Checks out 12,680.983 m
Since average atmosphere mass at 5.5 km
Seems reasonable

Lapse the 288K in 12,680.983 m ?

Franko #262

Height of zero KE = 12,680.983 m up

Seems a tad low to me at 1.2034e+01 T=2.2069e+02 KE= 2.7524e+03

Atmosphere is only so high (at calculated KE=0)
Height of zero KE = 12,680.983 m up

PE/KE = -503.968662 at surface from T=288K
KE/PE = -0.001984

But what is the equation, the exact solution, in between ?

Franko #260

Should be KE/PE=~-0 (zero)</blockquote.

Only at T=0 (zero) K or nothing is moving

Should be KE/PE=~-0 (zero)

v^2=G*M*(2/r-1/a) -- ellipse velocity at r
PE/KE=(-G*M*m/r)/((m*G*M*(2/r-1/a))/2)
KE/PE = (r-2*a)/ 2*a
a is half of the major axis
r is the particle distance from far ellipse focus

I was trying to get an equation for all allowed ellipses derived from ellipse and Earth's radius R. intersections. From there how to get to thermalized. ?

Anyway, as r and a approach each other, nearly a straight line, the result is KE/PE=~-1/2

Franko #257

PE/KE = 2*a/(r-2*a) produces a division by zero at the surface;
Invert KE/PE = (r-2*a)/ 2*a — derivativa=1/(2*a) How do you integrate all possible semimajor a to get RMS KE and temperature ?

I'm having a hard time picturing what you are trying to do.

Only one ellipse, cannot come out the other side, since orbit would make the boomberang come right back, (not only in Australia).

Argument abandoned, but we still need the PE/KE ratio as a function of altitude. The ratio is the foundation for all Hydrostatic, and Entrophy reasoning.

PE/KE = 2*a/(r-2*a) produces a division by zero at the surface;
Invert KE/PE = (r-2*a)/ 2*a -- derivativa=1/(2*a)
How do you integrate all possible semimajor a to get RMS KE and temperature ?

Argument revised;

Drop a molecule down, just missing the center of Earth
Travels not quite in a straight line; out the other side
Very flattened elliptically
Two foci, both near the surface
Semi-major axis very close to Earth's radius

One of the ellipse foci is at the Earth's center.
On the molecule bounce, switches to the other focus
A bouncing hocus focus pocus ?

Otherwise, can a molecule orbit the ellipse center ?

Per wiki “Elliptic orbit”
r is radial distance of orbiting body from central body
a is length of semi-major axis.

v^2=G*M*(2/r-1/a)
PE/KE=(-G*M*m/r)/((m*G*M*(2/r-1/a))/2)
PE/KE = 2*a/(r-2*a)

Earth surface from center = 6378137 m
Average atmosphere mass 5,500 m higher
Bouncing very tops of ellipses
So; PE/KE ~=-2 does hold in reality !

Franko #252

mean free path is about 68nm average velocity at room temperature is around 500 m/sec so expect a collision about every .14 ns at sea level. I'm not sure what you mean by radii exclusion zones

Between Maple and the online "Equation Solver", I got 22.76K/km. This is higher (than 9.8K/km), because the molecules do not have to collide, (insulate). How do I introduce molecular collisions, and radii exclusion zones ?

Ah hah! So somewhere there is a Wight Wabett?

Franko #248

Alice is in reality, really cooking by modulating Entrophy flow ?

Yes Franko every thing we see, do or make is powered by the entropy flow in a cooling universe.

Uhh.......Swahili? Ajerbaijani? Maldivian? Kriol?

The IsoEntrophy state of a point mass particle composed Universe is then Virial --point particles non-interacting ? Introduce particle size -- then collisions emerge. Matter collides, trips up the photons, slowing, (resisting, storing), the energy flow. Various insulators are variably effective in braking the lapse rate ?

Alice is in reality, really cooking by modulating Entrophy flow ?

Hmmm

"[Response: As far as I am aware, MEP theory has not produced any useful results, possibly because the climate fluctuations of entropy production are actually a very small fraction of the total entropy production and so are not usefully constrained by the theory (Stephens and OBrien, 1993; O’Brien 1997). Think of it this way - if the uncertainty in the climate sensitivity to doubled CO2 is a function of the micro-physics of clouds, how can a theory which neither contains greenhouse gases, clouds or micro-physics succeed in predicting that quantity? What about regional climate changes from the addition of aerosols? etc.

With respect to the diurnal or seasonal cycles in GCMs, why do you think they are not well-modelled? They’re not perfect, but the main features are well captured. I will however read the paper you point to and report back… - gavin]"

Followed a little later by a murmur of syncophancy from Alexander (definitely not you) Harvey. Some discussion, huh!

Given that this was back in August 2006 and GS' s references were 10 and 13 years earlier this is no discussion at all.

Significantly, GS seems to have been blithely unaware of the work cited in Lorenz's 2003 'Full steam ahead - probably' nice little two page review and (worse) the chapters (all excellent) in the 'Red Book' (Lorenz and Kleidon (eds), 2005) which sits beside me right.

Clearly MEP has not 'gone away' since 1993 - 1997.

If the activity of Fraedrich's mainstream group at Uni. Hamburg (I was a graduate summer school tutor there in isotope geochem 91/92 - probably drinking steins with them and never knew it) is anything to go by, there is plenty of meat on the MEP bone.

As Alice would say: "Curiouser and curiouser!"

My apologies, there is more discussion of this buried at RealClimate, even a very cursory response from Gavin Schmidt.

http://www.realclimate.org/?comments_popup=318

I copy these comments below as they're interesting.

Gavin promised to report back, but never did. Miskolczi should feel honoured to be categorised by RealClimate as not worthy of being repsonded to I think.

---

#

Is there a governing principle for climate and or weather?

Something along the lines of:

Climate evolves (tends) towards a state that maximises/minimises measurable climatic parameter(s) X(s). E.G minimising temperature maximising entropy.

Or of similar importance:

A deterministic climatic model evolves (tends) towards a state that maximises/minimises measurable climatic parameter(s) X(s).

In the later case, I presume, when climate models are allowed to run with constant forcings, etc. some collection of parameters stabilise in the long term. (Is this so?)

If it is then, it may be possible to construct governing equations that describe climatic tendencies in terms of the controlling parameters (by using the model with incremental changes of parameters to determine the governing equations, and to apply these governing equations to predict stable climates without the boredom of running the model each time. (I presume that something akin to this is done at least in the sense that micro-events like light showers can not be modelled individually but must be handled in terms of their regional significance.)

I haven’t the time to think hard enough about this just now but I think this is the same as saying that the fabric of climate space is relatively “smooth” e.g. free of cusps, deep holes, etc. and so would always tend to a unique point regardless of how far away the initial conditions are (is this true of the models?). Or do the models contain metastable states or are they multistable?

This is kind of important to know, I think.

If they do not tend towards a unique point is it true to say that a similar law has local validity.

E.g.

Climate and its model evolve (tend) towards a state that locally maximises/minimises measurable climatic parameter(s) X(s).

This is I think the same as saying that climate is locally stable in the long run. It might take a complex and chaotic path towards stability but that the tendency is clear and inevitable.

Can anyone say what is known of the models in these type of terms. Not whether they produce particular results or that they are useful but whether they stabilise in a unique way?

Comment by Alexander Harvey — 17 August 2006 @ 7:47

#

#123 Alexander. There are numerous papers and reports about modeling the climate, and other characteristics of planets, using a principle of maximum entropy production. Google the phrase “maximum entropy production” with ‘climate’. Bejan, Lorenz, Partridge, and others have papers and reports on this subject.

[Response: While this theory is aesthetically pleasing, it isn’t terribly well thought of in the community. For one, it doesn’t consider rotational effects at all, and doesn’t match lab experiments when rotation is included. And when it’s used to to predict anything, it gives the same answer as was known already (Kleidon et al, 2003). But for another view read Ozawa et al (2003). - gavin]

Comment by Dan Hughes — 17 August 2006 @ 10:15
#

This paper Constructal Theory of Global Circulation and Climate does in fact consider rotation and the abstract says, ” The earth averaged temperature difference between day and night was found to be approximately 7 K, which matches the observed value.”

Are you saying that the large literature on application of entropy maximum to analyses of the properties of planets has been dismissed by the climate change community?

It is my understanding that while GCMs do rotate neither the daily or seasonal variability are considered to be reliable. If this is not correct will you kindly point me to published results for these quantities.

[Response: As far as I am aware, MEP theory has not produced any useful results, possibly because the climate fluctuations of entropy production are actually a very small fraction of the total entropy production and so are not usefully constrained by the theory (Stephens and OBrien, 1993; O’Brien 1997). Think of it this way - if the uncertainty in the climate sensitivity to doubled CO2 is a function of the micro-physics of clouds, how can a theory which neither contains greenhouse gases, clouds or micro-physics succeed in predicting that quantity? What about regional climate changes from the addition of aerosols? etc.

With respect to the diurnal or seasonal cycles in GCMs, why do you think they are not well-modelled? They’re not perfect, but the main features are well captured. I will however read the paper you point to and report back… - gavin]

Comment by Dan Hughes — 17 August 2006 @ 11:50
#

#127. Gavin, and why should a model not prdeict what is already known? The GCMs do not predict at various spatial and temporal scales what is already known. This latter characteristic (not predicting) seems to be a major problem in contrast to the former (correct prediction) which many consider to be a major requirement of successful, useful modeling. The lack of the former in the GCMs is the focus of much discussion and debate.

Comment by Dan Hughes — 17 August 2006 @ 12:04
#

Gavin,

We can take this offline, but I can’t find your e-mail address on RC. You have not correctly characterized some of the MEP models. And I hope you will provide corrections online. Additionally, I asked for publications in which the daily and yearly variability from a GCM is reported. You merely stated that ‘it is good’. Kindly send me reference citations and/or report them on RC. And, kindly send reference citations to predictions of regional climate and comparisons with measured data.

Thanks

Comment by Dan Hughes — 17 August 2006 @ 12:33

I like the quote. See http://arxiv.org/abs/0812.1074
Also posted at journal club http://landshape.org/phpBB3/viewtopic.php?f=7&t....


Gets stuck into the idea that the uncertainty of GCM projections can be estimated from an multi model ensemble outputs ala IPCC (MME): "As a result, MMEs are sometimes referred to pejoratively as
“ensembles of opportunity”." They advocate parameter perturbation. The also stuff on impossibility of linear bias correction of a Lorenz attractor. Some stuff you might be interested in.

The real trouble with this world of ours is not that it is an unreasonable world, nor even that it is a reasonable one. The commonest kind of trouble is that it is nearly reasonable, but not quite. Life is not an illogicality; yet it is a trap for logicians. It looks just a little more mathematical and regular than it is; its exactitude is obvious, but its inexactitude is hidden; its wildness lies in wait.

G. K. Chesterton.

Eh, chihuahua!

Such a highly entropic planet, amigos!

Everything from Mexican Expert Pilfering to Imposition of Politically Correct Concepts (;-)

On the disappearance of MEP from IPCC. Meant as humour in this context.

News item, 16 Dec 2008, 10:20am | AFP

A TOP US anti-kidnapping expert has been kidnapped in northeast Mexico.

Steve #237:

What's the bet that if I post asking for their views on the MEP, my post will be deleted? ;)

Steve #233

Yes I meant fig 3. fig 2 kills L& M 2003 off completely and renders it quite obsolete. Even if everything else in M's paper is dead wrong Fig 2 turns L&M03 into landfill.

Tell me Steve why are you so bothered by M's one transfer function that gives a single value for a single temperature at what is for all practical purposes one level and not bothered at all by L&Ms two transfer functions, which is what equations 1 and 2 are, that give two different values for the same temperature that is quite paradoxically discontinuous with itself.

So what do you want me to make of this gobbledegook?

That $$\epsilon _G$$ is not 1 but close enough to 1 for the assumptions of eq (27) & (28) to be valid. You can see figure 2 for the the difference between $$\epsilon _G = 1$$ and $$\epsilon _G ' = 0.96$$ the precise difference it makes.

BTW ε is not eta (η) its the generally used symbol for emissivity which L7M set to 1 without even troubling to mention it because everyone makes the same assumption. If there is a problem with Ms paper it's not here.

Come on Jan, you don’t really buy this stuff do you?

Absolutely you talk about maximising entropy production and you want to leave out $$T_A \left(S_T\right)$$ which will have increased the entropy of the universe before your convection has drifted upward a micron or two. It does not make sense to leave out such an important factor that does all it's work and then some while convective are still looking for their socks. $$T_A$$ is the very real always observed atmospheric window that marks an important difference between L&Ms incorrect grey model and Ms more correct semi-transparent one.

All Ferenc has done, though he may deny it, is a bit of informal (almost trivial) linear programming in getting from equations 1 -3 to eq 8. It's not difficult.

Whether you choose to name atmospheric outward flux $$E_U$$ or K doesn't matter because they are algebraically equal. $$E_U$$ and K each have one value but 2 degrees of freedom each $$E_U = (F + P) + (S_T - A_A)$$ and $$K = H_L +H_S$$ where HL and HS are latent and sensible heat respectively. So your precious convection is not hidden in ST or TA but out in the open as $$E_U = H_L + H_S$$ if for constant F0, EU is also constant then it is obvious that to keep it constant when τ is increased and leads to increased HS, then HS must decrease. If that decreases you end up with less water vapour in the atmosphere and low pan evaporation rates and τ returning to it's original value. That is negative feedback at its best.

There are many little pebbles on the road to Damascus:

http://adsabs.harvard.edu/abs/2004SPIE.5572..384G

Franko#235

So, mate, buddy, friend of long standing - you little beauty! Drink beer do ya? Guiness? Stoli? My shout?

Whaddya wanna do to maximize the rate - trying for that bar of ~20 K/km for ~10 km?

Maximize APE/AKE? (Lorenz, 2003 'Full steam ahead-probably').

Vertical convective flux increase (Ozawa and Ohmura, 1997)

Horizontal heat transport? Fraedrich et al., all over it like a rash)

Generate aerosol haze way up high? (refer Pavlov's dog et al. 2001)

Crank up surface temperature discontinuity (max out radiative flux)?

Miszolczi: 'Computer says no' (its' all radiative 'equilibrium' anyhow). Spoilsport.

Alex#232

"Actually there was almost a RealClimate discussion of MEP here:..."

That's a really teeeny, tiny, 'almost' (;-)

Hmmmm. Interesting (putting aside quaint way with the sig. figs. ;-).

Right ball park for the tropopause (~10 km) but 'lapse rate' above the dry adiabatic - hence something wrong somewhere.

Inference: 22.7 K/km = sum of radiative + convective (sensible + latent)?

Implications: Ed? Aa? K? P? Warm water from surface?

Note Ramanathan and Coakley (1978):

Lapse rate dT/dz = (g/4R)*Fr*(tau/(Fr*tau + c)

=> Fr ~ tau^n?
Fr ~ (1 + tau) ^ n??
Fr ~ (1 + tau + exp(-tau)???

BTW Delta Entropy = Cp*Integral(1/T) dT = Cp*ln(T2/T1)

233 Steve Short
"for a lapse rate of 9.5 K/km and deltaT = 0 or lapse rate = 6.5 K/km and deltaT = 5 K"

Why does the lapse not ~= 22.7 K/km ?
Trying to approach from PE and KE -- Thanks

PE = -G*M*m/r
KE = (3/2)*k*T = (m*v^2)/2

PE+KE = -G*M*m/r + (3/2)* k*T
PE+KE = -3.005875592e-18 + 5.964409728e-21
PE+KE = -2.999911182e-18
PE/KE = -503.968662

Calculate surface TemperatureLapse
-2.999911182*10^-18=-G*M*m/r+(3/2)*k*T
T = (333343202292180416*m*G*M-r)/(500014803438270624*k*r)
dT/dr=-2*m*G*M/(3*k*r^2)= -0.0227563275
dT/dr=--22.7K/km (at surface)

Calculate height of zero KE
-2.999911182*10^-18 = -G*M*m/r
r = 333343202292180416*m*G*M
r = 6.390817983e6 (12680.983 m up)

G = 6.67300 × 10-11 m3 kg-1 s-2
M = 5.9736×10 24 KG
k = 1.380 6504×10−23 J•K-1
r = 6378137 m
T = 288K (surface)
m = 48.09584754104e-27 kg (one atom = 28.964*1.66053886*10-27)

BTW - I mean the skin flux Bo at surface temperature ts - I'm beginning to sound like M himself - see bottom of M7 page 14.

Jan #231

(1) M7 Fig. 2 is monotonic. Fig. 3 is not monotonic. I think you mean Fig. 3

(2) M7 Equation 20 is a construct based on an arbitrary (idiosyncratic) view that there is a 'transfer function' f which is somehow able to hide the relationship (if there is one) between tautilde and the convective heat transport process (see below).

(3) M7 reveals the nature of this smoke and mirrors exercise when he says (page 16; my note s in square brackets thus []]:

"So far at the definition of etaG we ignored the reflected part of the downward long-wave flux.[!] The true surface emissivity is: etaG = Ed*Ta/A. etadashG may be obtained from etaG by applying the next correction: etadashG = etaG*Ta/(1 - etaG*A). The energy balance at the boundary is maintained by the net sensible and latent heat fluxes and other energy transport processes of non-radiative origin. Further on we shall assume that the etaG = etadashG= 1 approximation and Eqs. (27) and (28) are valid. [NB: these are the ts^4 = te^4/f and Su = OLR/f equations] Let us emphasize again, that these equations assume the thermal equilibrium at the ground."

So what do you want me to make of this gobbledegook?

This and everything else that follows is an attempt to somehow say that the 'processes of non-radiative origin' can somehow be swallowed up in the Ta term and we can forget about lapse rate etc.

Come on Jan, you don't really buy this stuff do you?

I could as easily say that there can be maximization of entropy in the 1D radiative-convective way that Ozawa and Ohmura (1997) describe. They give predicted convective fluxes of 54, 77, 89, 96 and 110 W/m^2 for tau = 1,2,3,4,5.

M gets 143 W/m^2 for the surface radiative flux (piB0 = Fr) at a maximum of tau = 1.87 (M7 Fig. 3 again). This suggests the total convective flux is about 97 W/m^2 from Fc = Fs-Fr where Fs= 240 W/m^2.

Now take a look at Fig. 2 b in Lorenz and McKay (2003) i.e. some 4 years earlier. There Fs is fixed at 140 W/m^2 and Fc is predicted to be about 97 W/m^2 for a lapse rate of 9.5 K/km and deltaT = 0 or lapse rate = 6.5 K/km and deltaT = 5 K.

There could be an optimum there too. The difference between these figures is essentially that M has puts that pesky little -Ta term in there to kick down Fr (B0) at high tau.

So the question boils down once again to the real meaning of the skin temperature Bo.

Why should B0 actually reduce (slightly) at high tau while at the same time skin temperature is always above atmospheric temperature?

Is there a problem with Appendix B in M7? Is this 'optimum' you refer to real or is it an artefact? If M's logic is correct then why hasn't this new form of the flux equation been accepted and What is the 'extra mechanism' which cause that kick down - especially in the context where a high tau is encouraging convection?

This has to be 'real world' mechanism, not an electrical analogy.

Actually there was almost a RealClimate discussion of MEP here:

http://www.realclimate.org/index.php?p=517&...

A certain Jim Redden politely wondered if MEP considerations might cause a problem for the GCM GCM predictions/projections. Then, Alexander Harvey responded (who again I must point out is not me!) very politely. Ray Pierrehumbert had earlier spoken approvingly -- of Ralph Lorenz's lecture on Carl Sagan, although he had nothing to say about any of this!

Incidentally, anyone who is suffering from mathematical overload whilst trying to understand what MEP is all about (this is me unfortunately) might enjoy this popular introduction from Ralph Lorenz:

http://www.lpl.arizona.edu/~rlorenz/fullsteamah...

I prefer the way he has politely put it:

Despite the empirical agreement tuned into GCMs, this is [i.e. the physics of heat transport, convection etc.] an underconstrained problem with many possible solutions.

Undercontrained, indeed. Lorenz conludes wryly:

The MEP idea continues to generate considerable friction among climate modelers—but perhaps that is exactly what we should expect.

Wouldn't I love to hear Gavin Schmidt's view on this.

Steve,

The problem with only dealing with outgoing flux without recognising that the temperature on the surface affects the value of the incoming short wave flux this statement on page 412 has no validity:

Another approach may be to select the convective ‘resistance’ to maximise the electrical power dissipated in that element—i.e., the product of voltage difference and current flow.

because the resultant curve will be monotonic and have no maximum. Put simply referring back to maximum power theorem the power dissipated in the load is

$$P = I^2 R_L$$

With I (or incoming solar flux) constant

$$\frac {dP} {dR_L} = I^2$$

which is also a constant and there can be neither maximising power dissipation nor maximising entropy production. It's a fatal flaw.

But is nice to see that you think Rs = Wild Ass Guess (= Eu)

I find this somewhat mystifying as I can't see that resistance is equal to current nor can I see that flux is equal to τ.

I guess this makes Su (=2Eu) a Wild Ass Guess too?

No SU = 2 EU is empirical it might not be general but it is empirical not a guess. That is the challenge to find out if it is. If it isn't then what is a general expression if it is the fine let's move on.

However the bottom line is with regard to that figure 4 in L&M is that unless there is a way for there is an inverse relation of current to voltage with variations in Rtotal there can be no maximising of power dissipation.

If it is a fair analogue of their Eq 9, and I agree with them that it is, then there is no maximising of anything flux or entropy because as you can see from Fig 2b it's monotonic and no optimum.

FM's M7 equation 20 which is charted in M7 fig 2 is not monotonic and if you take a look at the red line in the graph on the wikipedia page has just the right shape and there is a optimum.

Points taken.

But in all fairness the paper is all about the relationship between the convective and radiative heat fluxes from the surface. they clearly say that i is the short wave flux reaching the ground. Thus Fig. 4 in L&McK (2003) is really only an analogue for the flux leaving the surface, not the system as a whole and I don't think they claim it as such.

Accurate parameterisation of the temperature of the surface and total flux (i.e. including the highly important sensible and latent heat) leaving the surface is precisely where M Theory falls down. It would be a foolhardy man who claimed it was not so.

Palming the surface leaving flux off as due solely to Kirchoff's Law is clearly BS (IMHO).

In L&Mk (2003) Rc is equivalent to tau (a simple function of) and hence a priori is only related to Vs (Ts) at the surface node in so far as one imposes a surface temperature (itself a function of i the heat flux deposited at the surface). So it takes us back to M and his 'transfer function' again. Ho hum.

At least L&McK (2003):

(a) give us convection; and
(b) provide an expression scaling Rc to Rt

But is nice to see that you think Rs = Wild Ass Guess (= Eu)

I guess this makes Su (=2Eu) a Wild Ass Guess too?

And here was me thinking you accepted M Theory!

Steve #228

I really wish Jan would look at the electrical analog model of radiative-convective equilibrium in Fig. 4 of Lorenz and McKay with the radiative resistance broken down into two, only one of which is shorted by a convective path.

I have looked at it I'm not entirely happy with it because it is half the potential divider an half the story when it comes to the selection criteria for $$R_C$$ or convective "resistance". In a real potential divider the current is controlled by both the input and output resistors so if you increase $$R_C$$ you will you must also decrease the current as the voltage at the node increases and vice versa.

The full description is here in then maximum power theorem.

For the resistive case the output voltage can be given by

$$V_O = \frac {R_L} { R_S} \left( V_I - V_O \right)$$

The current I is then given by
$$I = \frac {V_I - V_O} {R_S}$$

The natural analogue then for the earth's heat flux will be
$$E = \frac {\sigma \left(T_{SC}^4 - T_{surface}^4 \right)}{WildAssGuess}$$

that is no numerator in the equation this is in my mind a major failure the main point being though is that there is a limit to how hot the sun can possibly make the earth's surface. The equation set's that limit at 127 C which isn't very comfortable but the important point is I feel that the rise in temperature is actually part of the planetary homeostatic process that aught not be ignored.

Please note the equation ignores such things as atmospheric transmissivity, absorptivity etc that aught not be ignored either but omitted from clarity.

Hi Alex

Yes, it is very intriguing. FYI I have emailed Benny Peiser a post for CCNet. If he chooses to post it, which I'm sure he will as he is a very open minded fellow, it will be interesting to see what comments it 'flushes out'.

Actually the work of E N Lorenz was not understood to be consistent with MEP at all, it led to chaos theory:

http://www.exploratorium.edu/complexity/CompLex...

It was really the work of Australia's own Garth Paltridge in the early 1970 (following the work by Prigogine) which really started the ball slowly rolling.

The simple fact that the thicker the atmosphere (in terms of absorbers OR scatterers), the harder it is for heat flux to leave it radiatively and therefore the more convective flux (of both latent and sensible heat) there must be is IMHO a bombshell.

I'd dearly like to make Miskolczi's theory consistent with Paltridge, 1975; Lorenz, 2003, Ozawa and Ohmura, 1997 and Lorenz and McKay, 2003) with his vertical convective flux of latent and sensible heat K and P optimized to maximize entropy production - without regard to any critical lapse rate or surface continuity/discontinuity.

Something roughly like does it I think:

K + P = (Ed + F - F0)[0.5*tautilde/(1 + tautilde)]

I really wish Jan would look at the electrical analog model of radiative-convective equilibrium in Fig. 4 of Lorenz and McKay with the radiative resistance broken down into two, only one of which is shorted by a convective path.

Steve # 217:

Yes, I'd noticed that. Given that the roots of MEP go right back to Lorenz (196) and Paltridge (1974) and the body of literature is now getting rather substantial and accelerating, this is rather puzzling.

Well, I’ve been looking through the IPCC bibliographies and it doesn’t look like the authors were unaware of the work of E.N. Lorenz at all. Rather it would appear that they’ve just carefully ignored his MEP theory, citing all his other work but ignoring the MEP ideas. See IPCC2007, Chapter 1, ‘Historical Overview of Climate Change Science’. Historical revisionism, more like it? It seems fair to say they’ve passed over this in silence so as to avoid an obvious controversy. And I suppose, the scientists of this MEP movement must be equally happy to avoid controversy? No one is calling out, “Why is our work not mentioned by the IPCC?” Perhaps they prefer the silence; it means that they can continue their research without attacks from green activists & Al Gore. The plot thickens…

Geoff #225

sounds like gangrene had well and truly set in.

Jan Pompe 224

Had an intermittent RAM failure on one stick (though it passed onboard diagnostics) combined with a bad DSL line from exchange to here combined with an intermittent poor contact on mouse USB combined with intermittent modem failure, combined with self-reinstalling remnants from removal of Vista in registry, all at once. That was a hard diagnosis and would tax any backup.

Steve #222

Doesn't run on Ubuntu linux though: it doesn't appear to be compiling all the runtime programs - needs more investigation.

Geoff #223 I had hoped to be able to point you to an easy backup system so you don't lose all your stuff and even afford some protection from accidental deletions but installing rsync on xp isn't a trivial exercise.

Bit OT, apologies David, but to answer Jan's question, I have some expensive devices like photo scanners that are 5+ years old so the "new" machine was the latest I could find that supported them. It's just a dual core 3 GHz Pentium IV with 2 Gb server RAM and half a terabit storage on 3 x HDD. The video card is mor for @D than 3D, NVidia with heaps of on-board but a bit old in design. Runs under XP Pro, took Vista off as it seemed designed for kids with iPods and digital cameras. The slowest link is the DSL which is really third world. No fibre cable option exists here.

Jan#221

"PUMA builds and runs quite nicely on my Intelligently Designed iMac now I only have to figure out what it all means. It’s very pretty though."

I'm very envious.

You're welcome Geoff. What did you get? I got fed up with fiddling bought a mac and put an external drive on it and run time machine (I might upgrade to a RAID) I did the same for my daughter who had a major crash a week later and lost nothing.

Steve

PUMA builds and runs quite nicely on my Intelligently Designed iMac now I only have to figure out what it all means. It's very pretty though.

Thanks Jan Pompe for # 219. Now have a new computer. Regards Geoff.

Geoff #218

AR4 WG1
IPCC Home

Steve Short 217

I lost my download and link to IPCC AR4 in a crash. Do you have a link at hand? Have you done the simple thing of a word search for MEP, entropy, Paltridge, etc? I have not.

Prof Partridge wrote an article for the Australian journal "The Skeptic". I guess this indicates that he is not in the "club". So did former Tasmanian Governor Sir Guy Green, a former Chief Justice of the Supreme Court of Tasmania. Both are clear expositions from senior people, one a scientist and the other a lawyer by training.

Alex#214

"Interestingly, I am unable to find a single reference to the MEP literature at RealClimate. I haven’t found a reference to it in the IPCC report yet, although I’m still looking."

Yes, I'd noticed that. Given that the roots of MEP go right back to Lorenz (196) and Paltridge (1974) and the body of literature is now getting rather substantial and accelerating, this is rather puzzling.

FYI, I recently joined the MEP correspondence list run by Axel Kleidon (partly so that I could eventually pose that question to Lorenz we had agreed on from a very careful and diplomatic angle). To my surprise both Roderick and Farquhar at Australian National University are on the list and clearly enjoy a cordial relationship with Kleidon etc.

Given the lack of stratospheric heating, the reduction in tropical-polar temperature gradients, the trends in continental cloudiness, rainfall, potential evaporation, oceanic wind speeds etc I think we can reasonably expect to see a body of top level academic climate researchers in the next few years promulgating a more moderated view of global climate CO2 sensitivity and a more optimistic view on climate homeostasis and so-called ocean acidification.

When that happens I hope Miskolczi is accorded a bit more respect. In the meantime I'm battling with the surface discontinuity/lapse rate below/to the cloud layer (OLRA = Ed = OLR = Aa etc) problem. I'm still not convinced M has got that quite right.

#216 Hi Alex,

Interestingly, I am unable to find a single reference to the MEP literature at RealClimate. I haven’t found a reference to it in the IPCC report yet, although I’m still looking.

I doubt that you will. Maximising entropy or minimising energy and the positive feedback, required for the high climate CO2 sensitivity projections, are mutually exclusive.

Somehow I prefer a theory that results from empirical observations (MEP) to one that has apparently no empirical basis at all (water vapour positive feedback).

Steve # 210:

Interestingly, I am unable to find a single reference to the MEP literature at RealClimate. I haven't found a reference to it in the IPCC report yet, although I'm still looking. It really would be astonishing if it turns out that these self-proclaimed experts in climate science just didn't have a clue that this MEP theory even existed!

Hi Geoff. Acknowledged and points taken.

BTW, you will be interested to note that Kleidon et al. (2006) Maximum entropy production and the strength of boundary layer exchange in an atmospheric general circulation model. GEOPHYSICAL RESEARCH LETTERS, VOL. 33, L06706, doi:10.1029/2005GL025373, 2006

show that the climate sensitivity to a a 10 x increase in atmospheric CO2 is about 3.3 K. Noting the usual log-linear relationship this is equivalent to a climate sensitivity to a doubling of CO2 of about 1.0 K.

In this setup, entropy was produced by radiative transfer (absorption of solar and terrestrial radiation at the surface and in the atmosphere), the turbulent transport of sensible heat in the vertical, and horizontal heat transport by large-scale atmospheric circulation.

Due to the exclusion of the water cycle, entropy production associated with the hydrologic cycle [Pauluis and Held, 2002a, 2002b] was not considered.

I don't think I have to spell out what this implies for even the lower limit to CO2 sensitivity vis-a-vis IPCC AR4 2007.

Steve Short #210

I suspect you have your wires crossed with my #209.

My point is that one does not have to invoke a spiritual sorce of explanation for science. I do not believe there is a religion or a need for religion, except in the minds of the superstitious or uncertain or propagandised.

The personal proclivities of past great scientists who were also confessed religious zealots does not play on my mind. For all I know they might have been vegans too, or wore socks of different colours, but that is of no interest, only their science is of interest.

I'm not knocking Ferenc, quite the opposite, and there is concordance with what Garth and Lorenz wrote, at a plane of understanding higher than mine. I'm not knocking them either. Not in the least. I read Jim Lovelock from when he started to become quoted and there's a bit on nonsense in some of his concepts, where they are speculative, unsupported and not later shown to be actual.

I do however share your comment that the 'religion' of concern is the alarmist AGW bandwagon. I thought I had made this quite clear in numerous postings. Some of the stuff James Hansen has uttered is absolutely frightening.

BTW, I majored in Chemistry also.

Re Steve Short 94.

You note some of the papers of Fort, who has a fascination with numbers.

So do I. One of the wonders concerns the sunflower (and many other plants). One can draw radiating arcs from the centre of a photo of a sunflower, following the obvious divisions between seeds. Some arcs are left handed curve, some are right handed. If you count the number of each, it is very common for them to be consecutive numbers in the most common Fibonacci sequence, 1,1,2,3,5,8,13,21 etc. Terms like parastichy and phyllotaxis can be searched. John Rouse (now dec'd) of Physics Dept Melb was a major researcher. I have a collection of papers. The wonder is that the first seeds form in the centre and are pushed outwards by successive ones. But, they are pushed outwards sequentially at a magic radial angle of 137.507 degrees where the last significant figure matters, as can be shown by generating synthetic diagrams that degenerate after too many iterations.

People have examined packing theory etc but the conclusion I currently find most appealing is that the conformation complies with frugality of entropy. Obtuse, but of continuing fascination. Entropy is all around us, wherever we look, even though we can't see it, like you can't see the "mind" of a person yet medicos can decribe "mental ilness".

Jae#208

"SS: that melding of science and religion is tough."

Geoff #208

Sorry, but that is simply BS.

No religion at all. Lorenz, Kleidon, Ozawa, Fort etc etc are all reputable scientists.

Even Lovelock is/was a scientist (analytical chemist). It's no fault of his that in his old age his thermodynamics proves to not really be up to par.

Don't be put off by the Gaia word - there is a lot of subtle science behind that notion.

Bottom line: Ralph Lorenz (US; 1960) and Garth Paltridge (Aust; 1974) started the MEP viewpoint right there in the mainstream journals and it has rolled on since, only getting stronger year by year.

The only real religion here is the AGW alarmist bandwagon which even ignores see the alternative body of mainstream science which shows their world view and GCMs are just not up to scratch.

Science spawned AGW and only science will put it in it's proper place.

Please don't insult the many patient scientists who will put it in its place from your position of ignorance until you have read their literature thoroughly and can actually refute their views mathematically. My own field is solution (aqueous/mixed solvent electrolytes) chemothermodynamics (I actually make a buck in hydrometallurgy) and MEP looks very sound to me.

The only tragedy of Miskolczi is that he tried to go it alone in an idiosyncratic way without actually absorbing the MEP literature. Davids usually do not beat Goliats.

The mechanistic underpinning of Miskolczi's insights is undoubtedly MEP. What a pity he didn't go to Uni. Hamburg or Max-Planck Institute for Biogeochemisty in Jena and just sit down and talk to them.

[IMG]http://i260.photobucket.com/albums/ii14/sherro_2008/cat.jpg[/IMG]

BTW, Forget about Gaia. It does not stand heavy scrutiny. It's a bit like that silly Intelligent Design was, or Cold Fusion, designed for newspaper writers looking for sensation. Religion simply does not enter the General Theory of Science. 1+1 =2 with or without God.

SS: that melding of science and religion is tough.

"Don’t be mean you gotta post one at least."

OK:

M has an explanation
Which causes great consternation
The elitists can’t agree
Their eyes too closed to see
So they resort to obfuscation.

Abstract. Are there any general principles that govern the way in which life affects Earth system functioning? Most prominently, the Gaia hypothesis addresses this question by proposing that near-homeostatic conditions on Earth have been maintained "by and for the biosphere". Here the role of the biota in the Earth system is described from a viewpoint of nonequilibrium thermodynamics, particularly with respect to the hypothesis of maximum entropy production (MEP). It is argued that the biota introduce additional degrees of freedom to Earth system processes. Therefore, we should expect biotic activity, and Earth system processes affected by the biota, to evolve to states of MEP. The consistent effects of the biota on entropy production are demonstrated with a conceptual model of biogeochemical cycling, by using extreme climate model simulations of a "Desert World" and a "Green Planet", and by a simple coupled climate-carbon cycle model. It is shown that homeostatic behavior can emerge from a state of MEP associated with the planetary albedo. This thermodynamic perspective is then discussed in the context of the original Gaia hypothesis and in light of a recent discussion in Climatic Change. Potential implications of the MEP hypothesis for global change research are also discussed. It is concluded that the resulting behavior of a biotic Earth at a state of MEP may well lead to near-homeostatic behavior of the Earth system on long time scales, as stated by the Gaia hypothesis. However, here homeostasis is a result of the application of the MEP hypothesis to biotically influenced processes rather than a postulate. Besides providing a fundamental perspective on homeostasis, the MEP hypothesis also provides a framework to understand why photosynthetic life would be a highly probable emergent characteristic of the Earth system and why the diversity of life is an important characteristic of Earth system functioning.

Kleidon (2004) "Beyond Gaia: Thermodynamics of Life and Earth System Functioning" Climate Change Vol 66 (3), 271 - 319

good one

thanks

Pity Schroedinger's darling feline
In a state we cannot define
But it's super-position
Gave Erwin his frisson
Only the pussy can say it was fine

#202 hi Steve

Strongly resisting the temptation to post limericks

Don't be mean you gotta post one at least.

Please.

Strongly resisting the temptation to post limericks related to Schroedinger's Cat (there are literally dozens of good ones - especially in German) I'd simply like to say:

www.sussex.ac.uk/Users/jgd20/lisbon2007/present...

Re #200 Hi Geoff

Point taken. however bear in mind at 15 billion years she's still a fast growing teenager she wants to be kewl.

Seriously though I don't think there is or can be a more convincing argument of the the utter entanglement of MEP with MEP.

She had her one Planck's instant of zero entropy and maximum temperature and potential and like a typical teenager wasting that potential on an ever expanding entropy just to be cool.

I once saw an enthalpy upon a stair, but next day there was nought but cat hair.

Watch out! this is certain proof that someone called Erwin Schrodinger was on the prowl last night and looking for your cat.

Re 199 Jan Pompe,

" ..... the Universe just wants to be a cool cat."

Would it not be more correct to say " ..... the Universe just wants to be an undisturbed cat"?

I once saw an enthalpy upon a stair, but next day there was nought but cat hair.

Steve #198

I once wrote an assignment called "Requiem for a Quantum Cat" got extra marks for the title. You know of course that it was a failed attempt at a reductio ad absurdum it failed because the absurdity turned out to be the reality.

The Multiverse beats Mr. (trust me) Intelligent Designer hands down any day.

I'm not so sure I got rid of a lot of headaches when I embraced Intelligent design and bought a Mac and moved Mr Multiverse who kept crashing to the garage where he still sits awaiting council clean up.

As for MEP, it's really just a personal preference, IMHO it's just a complex way of stating the bleeding obvious i.e. the Universe just wants to be a cool cat.

Hi Jan

IMHO there is no point talking about minimum energy in the global climate context unless you are talking about minimum available KE versus maximum available PE. As Lorenz showed the system tends to maximize APE at the expense of AKE and as Ozawa and Ohmura then showed that is exactly equivalent to maximizing entropy.

It is all very interesting. This means that as CO2 goes up and TENDS (!) to increase troposphere temperature, MEP requires that meridional, latitudinal and convective movement must increase. This in turn increases cloudiness (both convective and orographic) and hence rainfall thereby increasing the net amount by which clouds reduce the radiative heating of the planet i.e. presently the -13 - -21 W/m^2 which acts against the ~4 W/m^2 predicted for a doubling of CO2 (incl. gain!).

As you know I also believe that increased CO2 increases continental plant biomass (already observed) and oceanic cyanobacterial primary productivity (recall I posted proof of that from NOAA's own data on Jennifer Marohasy's blog) simply due to CO2 fertilization which increases biogenic aerosol production rate which increases both aerosols and cloud nucleation rate. This is the as-yet almost completely forgotten biotic sibling of abiotic MEP.

So thanks to both abiotic and biotic MEP we will get a cloudier, rainier planet rather than a hotter one. CO2 may go where it will but I suspect it will eventually slow to a crawl. The same thing will happen to any oceanic pH decline as increased raininess increase continental weathering rates which increases the export of total alkalinity, Fe and Si into the ocean (which increases primary productivity and so on).

Even for Australia there is proven long term net increased rainfall and cloudiness over the period 1948 - 2004 and of course the AGW orthodoxy want to write this off to increasing Asian anthropogenic aerosols (Rotsayn et al. 2006) despite the fact these only started increasing around significantly around 1975.

Thanks for posting the link on entropy Geoff. I lurv entropy. Entropy leads to Schrodingers Cat which leads to the marvellous Hugh Everett which leads to the Multiverse. The Multiverse beats Mr. (trust me) Intelligent Designer hands down any day. You listnen' BPL?

Geoff #196

Now where does enthalpy fit?

I think i saw an enthalpy shaped hole in a chem lab once but can't be sure it was long ago.

Your posted link to the entropy tutorial is a good one I think it confuses many people me included which is why I prefer to stick with minimum energy the other side of the seesaw.

Re Steve #195

Yes, I have brushed up on Lorenz as well and note the confusion in terminology. (If you want terminological inexactitude, try Steve's CA "Fleitmann 2007: "Observed Anti-Correlation" ).

Thank you for your comment and for the context with F. Miskolczi. I was a bit cheeky putting up a tutorial on entropy, but many people find it confusing, as indeed I still do at times. Now where does enthalpy fit?

Geoff#193

"Australia’s Garth Paltridge was one of the first people to apply the principle of minimum entropy to the atmosphere."

That is actually the principle of Maximum Entropy Production (MEP). When a system is at a state of maximized or nearly maximised rate of entropy production the exchange of entropy around the system is at a minimum. Garth's early language got people rather confused.

But the field has come a very long way indeed since 1974 and it is now understood to be essentially MEP. While Paltridge talked about minimal exchange of entropy in such systems, Ralph Lorenz also showed that this tends to be manifested in the maximization of available PE at the expense of available KE.

More recently it has been concluded that this tends to maximize both vertical convection and latitudinal heat exchange. Thus I have no doubt that the fundamental causation behind Miskolczi's interesting deductions about a sort of homeostasis applying in an (interglacial, non-Milankovitch-driven only) Earth climate system is MEP.

This solves the problem with the fruitless search for a non-orbital energy minimum between the desert Earth (evaporated oceans) and Snowball Earth as e.g. Gorshkov and Makarieva explored. The reality is not an energy minimum (unfortunate term sometimes used by Miskolczi) but an entropy exchange minimum (Paltridge) which equals an available KE minimum and hence available PE maximum (Lorenz).

Thanks David.

FYI, here are some excellent sites which have or lead to MEP-related papers:

http://copernic.udg.es/QuimFort/fort.htm

http://www.mi.uni-hamburg.de/index.php?id=414&a...

http://www.bgc-jena.mpg.de/bgc-theory/

May I also recommend the excellent 2005 text edited by Ralph Lorenz and Axel Kleidon:

Non-equilibrium Thermodynamics and the Production of Entropy: Life, Earth and Beyond.
ISBN 3-540-22495-5 Springer-Verlag Berlin Heidelberg

I've recently learned that there are even some Linux PC-compatible basic GCMs known as The Planet Simulator and PUMA (Portable University Model of the Atmosphere) out of the excellent Meteorological Institute at Uni. Hamburg which allow one to explore MEP-related effects. Something for 2009 perhaps.

http://www.mi.uni-hamburg.de/TheoMet.6.0.html

A neat non-mathematical description of entropy is at:

http://www4.ncsu.edu/unity/lockers/users/f/feld...

Note that entropy is an elusive property, more formally from Wiki:

Entropy, S, is not defined directly, but rather by an equation relating the change in entropy of the system to the change in heat of the system. For a constant temperature, the change in entropy, ΔS, is defined by the equation ΔS = ΔQ/T, where ΔQ is the amount of heat absorbed in an isothermal and reversible process in which the system goes from one state to another, and T is the absolute temperature at which the process is occurring.[7] If the temperature of the system is not constant, then the relationship becomes a differential equation dS = dQ/T . To understand what this equation means, suppose the temperature T can be expressed as a function T(Q) of the heat Q . (more)

Australia’s Garth Paltridge was one of the first people to apply the principle of minimum entropy to the atmosphere. I have not been able to locate the full 1974 article yet, so here is an abstract..
Global dynamics and climate - a system of minimum entropy exchange
G. W. Paltridge
C.S.I.R.O., Division of Atmospheric Physics, P.O. Box 77, Mordialloc, Victoria 3195, Australia
ABSTRACT
It is found that the mean meridional distribution of temperature, cloud cover and meridional energy flux can be predicted with extraordinary accuracy by application of a simple minimum principle to a multi-box model of the globe which contains no direct specification of the system dynamics. The minimized quantity is related to the global net rate of production of entropy. It is the sum over all latitude zones of the ratio of net radiant energy input to the effective emission temperature of the zone. The result suggests that global dynamics is something of a passive variable which alters so as to satisfy a condition akin to minimum energy dissipation.
Received: 7 October 1974; Revised: 17 December 1974

I offer no commentary here. Just trying to help to have us all talking on the same wavelength.

Paper Titan, Mars and Earth : Entropy Production by Latitudinal .. added to journal club here. http://www.landshape.org/phpBB3/viewtopic.php?f...

Franko #190

The F part of Fo — radiation the atmosphere at the top absorbs, is emitted back out — mean free path effect contained. Similar reasoning as the bottom Aa=Ed. Atmosphere absorbed = Emitted down ?

Some F is thermalised and finds it's way out again as part of $$E_u$$ some gets used to turn $$O_2$$ to $$O_3$$ (UVa) and then some lower band (UVb) turns $$O_3$$ back into $$O_2$$ - seems a waste but otherwise turning skin to cancer. That gets thermaised eventually too. Some photolyse the water that does get up there and some render aerosols (hopefully) harmless. Mean free path is longer up high. So answer is yes it doesn't get down to trouble us.

Same reasoning down below but mean free path is smaller and the air optically denser.

The F part of Fo -- radiation the atmosphere at the top absorbs, is emitted back out -- mean free path effect contained. Similar reasoning as the bottom
Aa=Ed. Atmosphere absorbed = Emitted down ?

Will try to write a small basic program
Process control theme, follow the grey photon ?
Limiting the things bouncing around to get ides.

"Now to justify optical depth ?"

It will be deep!!

Thanks !
Now to justify optical depth ?

Franko #185

my dear chap I think you might have it. just about but

On top
Potential converts to kinetic
Kinetic converts to radiation

I would put :
On top
Kinetic converts to radiation
Potential converts to kinetic

Brilliant and succinctly put nonetheless

Su = 2 Eu –--– PE=2KE
dSu/dEu=dPE/dKE

On Bottom
Radiation converts to Kinetic
Kinetic converts to Potential -- dPE/dKE=-2

On top
Potential converts to kinetic
Kinetic converts to radiation

Radiation up and down, cannot escape the Bottom
At the Top, radiation up and down, escapes the Up

Energy is convected Up as Potential Energy
Both Su and Eu are internal gas temperature indicators

Franko #183

However; only particle Earth is allowed inside Earth’s radius. Does this effect the -2 ?

Mean free path is so small we can only imagine it potential energy remains approximately zero. Collisions with surface if elastic won't change the kinetic energy if not elastic it will heat or cool and if the temperature doesn't change, and it can't in a static model, the average warming and cooling of all the little particles will be zero so the average kinetic energy (i.e. temperature) doesn't change.

I'm drinking too much coffee.

To do a proper Virial, Even planet Earth particle included. -- We have to calculate everything, --potentials relative to infinity. -- However; only particle Earth is allowed inside Earth's radius. Does this effect the -2 ?

Alex #181

Could you explain, perhaps, what you mean by the derivative holding, “even for a very small part” ?

The derivative is the 2 + holds for individual molecules that travel up and down through the atmosphere we don't get much smaller than a molecule except maybe in the thermosphere where there might be some plasma from time to time.

Franko # 177:

Could you explain, perhaps, what you mean by the derivative holding, "even for a very small part" ?

Alex # 174:

Nick asserts that Pochas #176

Jan # 175:

That is #276 in case someone wants to use number to search.

Or was I predicting that pochas would post again at # 176 on this thread? So the world really is filled with odd coincidences. ;)

Nature abhors a density inversion.
Bottom of ocean can be colder, or warmer
But not for long density inverted.

Fog inversion, above a swamp, is energy flow supported.
Untill the temperature difference runs out.

176, pochas

" believe it is possible in principle to have an isothermal atmosphere with a pressure gradient, although you may never find an example of one in the solar system. The ocean gets colder as you go deeper. Is the energy of a water molecule related to its depth? I conclude that the temperature gradient in the atmosphere is the result of the thermodynamic properties of the air/water system."

?? I don't see how you can pull that off without running afoul of the gas law. Liquids are different, since they are essentially incompressible and give up the relevant energy when they condense??

Su = 2 Eu --&-- PE=2KE
dSu/dEu=dPE/dPE
Add appropiate integration constants to get steady state numbers

Atmosphere is the top of a Virtual Virial System.
But the derivative does hold, even for a very small part.

I no longer think that the virial rule applies to this situation; the Eu = 1/2 Sg relationship is fortuitous. Put the earth and its atmosphere inside a Dyson sphere with inside temperature at 15 deg C. The earth and its atmosphere will eventually come to the same temperature, 15 deg C. Any remaining temperature gradient could be used to drive a perpetual motion machine, violating the second law of thermodynamics. But still the gravity field and the atmospheric pressure gradient will remain, so I believe it is possible in principle to have an isothermal atmosphere with a pressure gradient, although you may never find an example of one in the solar system. The ocean gets colder as you go deeper. Is the energy of a water molecule related to its depth? I conclude that the temperature gradient in the atmosphere is the result of the thermodynamic properties of the air/water system.

There are other arguments for Eu being independent of Sg that quickly emerge when you do an energy balance. I can elaborate on this on another occasion.

This is not meant to be critical of M's work. For me, it is an eye-opener. After studying his paper and working through his assumptions I feel I now have something of an understanding of how the atmosphere works, although I do feel some tailoring of the theory would be appropriate. I'm eagerly awaiting more from M in the future. I'll be away for a week, but will check back later for comments.

Alex #174

Nick asserts that Pochas #176,

That is #276 in case someone wants to use number to search.

Perhaps in Neal’s function, P( r ) is pressure as a function of radius;

P(r) is a function of radius and right fully belongs with KE as I see it but $$P_{r=R}$$ or $$P_0$$ both represent pressure at the surface a boundary condition since it is held as a function of radius and the radius is constant $$P_{r=R}$$ is a constant. If the independent variable on which the dependent on depends is a constant so is the dependent variable.

It makes no sense here to add another variable like T (as Nick tries on) which in a static system also depends on r.

Franko # 173:

I do wish I could understand!

Nick asserts that Pochas #176, page 1 of greenhouse-heat-engine thread, is wrong to hold that the second term of 'Neal's function' can be held constant, the assumption that must hold in order to differentiate and arrive at Ferenc's relationship.

Perhaps in Neal's function, P( r ) is pressure as a function of radius; you are saying that since the radius of the earth is so large, any small change in r caused by variations in the atmosphere's thickness must be negligible. Is this correct?

alexharv074 on Tue Nov 25, 2008 2:49 am
"Nick, I'm trying with my 'lawyerly' questions to get to the essence of what this disagreement is about"

GodZilla particle called Earth dominates.
Beneath the surface is an exclusion zone. -
All others are wrong.

Above the surface is still ~ r^-2. But the effect is less than r^-1 (more than just a constant.) -- Subtract Sun, Moon, centripetal) and 0.601 ?

Take only the outer part of a complete Virial System and not -2 is PE/KE
Earth radius = 6378.137 km - add another 100 km -- and little difference.

Su = 2 Eu
Both are derated, and describe gas internals.
Su by absobitivity
Eu by emissivity

Emitted flux is 1/3 internal flux
Top internal flux determines top temperature
Bottom internal flux determines bottom temperature

Hence, we have convective heat transport between T2 and T1 ?

Why the number 2 ?

Here is the impact of changes in water vapor with temperature if you want to refine your greenhouse model.

Effect of air density variations on greenhouse temperature model
Javier Leal Igaa, Jorge Leal Igab, Carlos Leal Igac, & Ramiro Ayala Floresd
Mathematical and Computer Modeling, Volume 47, Issues 9-10, May 2008, Pages 855-867, (online 19 July 2007.)
http://www.sciencedirect.com/science?_ob=Articl...

David #169

Thanks

I am not sure the VT is even needed

It isn't really there are many "virial theorems" for example they are just ways to deal with the woods rather than individual trees statistically. I think.

Jan, Not sure either, though I don't see much point in averaging PE say. At risk of going OT, I am not sure the VT is even needed. I mean, if energy is equipartitioned between the atmosphere and surface, as seems to be the assumption, then the 50% Eu of Su comes out quite naturally.

David #165

I am not at all sure we should be integrating the {PE} and {KE} I actually rejected the idea when Neal brought it up back in July. My reasoning then was (looking back on it it's perhaps not clear) the equation
$$\dot G = \displaystyle \sum _{i=1}^N m_iv_i^2 + \displaystyle \sum_{i=1}^N \mathbf F_i \cdot \mathbf r_i = 2 + = 0$$

clearly shows that the averages are an ensemble of particles where particle has a particular kinetic energy for a particular potential energy. I thought it better (and still think so ) just to take what we have and compare the computed kinetic energy at the level where I have the data with it's potential energy at the same level rather than guess at what the average might be over the interval between samples. I see it more as a statistical issue rather than a mathematical one.

Using octave to a trapezoidal integration is a simple matter of typing trapz(Height,KE) or just trapz(KE) the latter assuming linear equal intervals they both yield different results but none the same as Nicks.

Your thoughts? Is it better to treat it statistically with the KE an PE for each member of the population or to try and integrate?

Geoff, I am setting up a system so people can enter their own quizzes/questions. If you would like to phrase it with a set of possible answers I could enter it for you. Cheers

This is a bit OT but is prompted by mention of Simpson's rule and applies to other methods like Taylor expansions. I have a son who is a graduate surveyor, who laughs a lot at some efforts of home-made ways to measure distances over the globe (as when looking in grid cells for nearest neighbours for temperature adjustment). We devised an exercise for measuring the distance from a prominent building at Oxford Uni to the college room I once inhabited at Sydney Uni while experimenting with the female form. The purpose was to see if peoples' software coped with series and approximations, with the change of sign that can happen on crossing Equator and Date Line, the accuracy of canned software and so on. I posted it on the message board at CA then had catastrophic computer failure and a few weeks abroad, so it has lapsed. Given that the Google Earth solution is rather wrong and that the reference answer is done by ways that carry adequate significant figures, would my friends on this blog like to have the exercise to perform? Admin, you might issue a permit if you think it's OK, it's your blog.

Pliny: I was just questioning your assertion that Neal had been vindicated. Perhaps not. As you were;-)

Nick #163

How many times and how many different ways the potential of the atmosphere relative to ground is negative because it won't collapse unless you cool it i.e you have to take energy out of it. I agree it's better to use a numerical integration for the KE but it is hardly necessary for something that is to a very close approximation from 0 to 70km in height is beyond me. And that range of KE is from 0 to approx -20kJ/mole at the top and a mean value of 2016J/mole is nonsense.

David #158
The calculation of PE relative to infinity, which is what is required for a gravitational virial, is clearly very high relative to PE; I don't think that is disputed. But it has the right sign. The calculation of PE relative to ground gives a result which is clearly positive, and the theory shows that it is 2*KE=3*PE. There is a reference to an earlier calculation for spherical geometry, but the effect of curvature is reflected only in the minor change in g as you go up in the atmosphere. So the proof there is very simple, and I'll post it if people are interested.

But the latest is that I re-did Jan's numerical integral using the same TIGR data, but with Simpson's rule integration and proper accounting for density, and sure enough, PE=.669 * KE. No fancy theory, just numerical integration of pressure and temp data.

franko #23

Are engineers ignoring this silly talk ?
After all, the Earth needs terraforming

All the engineers I know are ignoring Spencer Weart and the organisation (Environmental Media Services) altogether.

NO formula provided is {PE}

admin #158

<Pliny: So where is the vindication? I went to the link and the discussion seems to be still hot and heavy.

Do you think I should tell him the sign of $$$$ is negative because work has to be done on any high flying parcel of air to make it come to ground level and it's negative because the kinetic energy must be reduced i.e. cooled to do so?

Is the PE/KE discussion going to drift into locally correct, pressure contained, -2. But, like the Kirchoff, bounded approximately, only in distances not greatly exceeding mean free path ?

r^-2 almost linear for short distances above the surface. The r in r*ω^2 acts opposite. Complicated field to deal with globally.

Pliny: So where is the vindication? I went to the link and the discussion seems to be still hot and heavy.

Mass Earth = 5.148 e18 kg
Molecule=28.95*1.66 e-27=48.14e-27 kg
Number of molecules = 0.1069 e45
PE=5.148 e18*9.8*5.5e3=277.5e21 J
Kb=1.380 6504e−23 J•K-1
T=2*KE/3*N*Kb -- 2*KE=PE
T=277.5 e21/3*0.1069 e45*1.38065 e−23
T=277.5/0.44277 e-1
T = 626.7 K

If field is linear then KE=PE
T=313.4 K

Further, include r*ω^2 the r is in opposite direction

Any way to get correct temperature?

Virial discussion, with a vindication of Neal, resumed here.
http://climateaudit.org/phpBB3/viewtopic.php?f=...

12 -- onward Pat Cassen, Neal J. King, Nick Stokes , Jan Pompe is also a good one to read ovet. http://landshape.org/enm/radiative-equilibrium-...

Neal J. King got over-confident, with Pat Cassen's support. For a while, he had a good argument going. But disproving the Virial Magic was impossibly difficult.

We should pick up the virial, radiation version, again,
Aa=Ed discussion has been exhausted.

Ferenc's post at http://landshape.org/enm/greenhouse-heat-engine/, # 281 also makes a little clearer his appeal to the principle of maximum entropy-production (I'm going to be very careful with hyphens from now on):

I am a bit confused with the term ‘empirical’. As long as you look at the simulated data poins and they show that Su=3OLR/2 (Earth) or Su=3OLR/(2+Ta) (Mars) with a reasonable correlation, they are certainly empirical.

But if you accept the theoretical assumptions that the LTE requires the Ed=B(1-Ta) (Atmospheric Kirchhoff law) and the system maintains the maximum greenhouse effect (based on the entropy maximum principle) and you derive the above relationships from the (Su-OLR)+(Ed-Eu)=Fo or (Earth) or (Su-(OLR-St))+(Ed-Eu)=Fo-St (Mars) energy conservation equations then these relationships are not anymore ‘empirical’. They are in fact based on theoretical assumptions (not to be confused with ‘approximations’) which are supported by empirical (simulation) data.

It's a nice quote, I think, that may yet sum up a great contribution to climate science.

Steve # 145:

Thank you for this post.

Eric#150

"It is incorrect to confuse the two, and treat MEP as a fundamental law of physics."

Strawman alert

My above post was meant for Jan.

Jean,
The point that you are missing is that MEP is the result of empirical observations, which may or may not apply, and refers to rates.

The 2nd law which is a fundamental law of physics says that in a closed system the entropy will increase to its maximum state, but nothing about a rate.

It is incorrect to confuse the two, and treat MEP as a fundamental law of physics.

Nick #147

MEP is a theory about the time rate of entropy production.

You're learning.

There was significant thought given to the original, precise formulation of statements like Heisenberg uncertainty, the Laws of Thermodynamics, etc. I find the mathematical expressions most satisfying when they are rigidly observed and less satisfying when essayists and novelists use them in inappropriate settings.

One has to be extremely cautious in taking difficult concepts like entropy into real life settings and assuming that this or that applies. Rates have been mentioned already as a complication, equilibria are another, bounds are another, complex mixtures are another, human intervention and irrational behaviour also.

Agreed that "Maximum Entropy Principle" or MEP rolls easily off the tongue and that its essence can be expressed in simple maths in known systems. BUT, that does not mean it can be applied with gay abandon (as we used to say in unpolluted times) to any situation that seems a convenient candidate. I have seen entropy used in quite inappropriate explanations by people without mathematical backgrounds, even in explaining why some money trading systems work in certain ways.

Please, let's be careful definitionally.

Jan #144
"you are talking about the rate the entity is produced"
Steve has picked it up there. Yes, you can talk about it. But what science says about the amount and what it says about the rate is different. "It's not just hyphens". Most established conservation laws are about amounts. A tank full of petrol will give a certain amount of energy, and no more. Theres nothing in the petrol that determines the power that it can produce. You can liberate the energy in a few seconds if you want.

MEP is a theory about the time rate of entropy production. And it is just a theory. Ozawa et al point out that evidence is accumulating. Maybe so, but we aren't there yet.

Mars -- regulated by CO2 and sandstorms
Earth -- H2O and optical depth
Venus -- Total cloud cover -- what else ?

One regulator dominates in a certain range,
Then another one takes over

How high solar flux, for Earth, is needed to go beyond
the regulating effects of H2O partial cloud cover ?

Oh dear. What have I started again? I have just waded through the CA exchange June to August as Alex suggested . Thanks Alex. I especially liked this bit by Neal King:

In this river system issue, they've noticed that the drainage networks seem to evolve into a structure that is most efficient in draining the watershed; so then they are postulating a minimum energy-dissipation state. Notice that this is not a lowest-energy state, this is a lowest energy-dissipation state: They are explicitly assuming a principle that minimizes a rate. They are not deriving a minimum rate from the existence of a lowest-energy state. Keep your eye on the ball. This is not just a matter of where you put the hyphens, it's a question of what is being minimized, an energy or a rate. If you postulate a minimum rate, then you "justify" a minimum rate. But if you postulate a minimum energy, you get a minimum energy, not a minimum rate."


May I try my hand at another version?

"In this global climate system issue, they've noticed that the vertical and horizontal air and sea networks seem to evolve into a structure that is most efficient in spreading the entropy; so then they are postulating a maximised entropy-production state. Notice that this is not a maximum-entropy state, this is a maximised entropy-production state: They are explicitly assuming a principle that maximises a rate. They are not deriving a maximum rate from the existence of a maximised-entropy state. Keep your eye on the ball. This is not just a matter of where you put the hyphens, it's a question of what is being maximised, an entropy or a rate. If you postulate a maximum rate, then you "justify" a maximum rate. But if you postulate a maximised entropy, you get a maximised entropy, not a maximum production rate."

Sorry guys.

Look I just think that Gorshkov and Makarieva hit the nail on the head when they showed that the two minimum energy states we can be sure of are a totally frozen Earth or one with a fully evaporated ocean. But they were also smart enough to point out that there was a lot of evidence e.g. the paleoclimatic record for some sort of metastable state or some unknown means of stabilizing the so-called maximum in between. As a former isotope geochemist I can tell you that you would be hard pressed to infer a CO2 sensitivity from the paleoclimatic record more than 1.5 K. With all due respect to Berner and others even that number involves a lot of relatively optimistic 'spin'.

Gorshkov and Makarieva were also wise enough to suggest on energetic grounds that the global biota probably play some stabilising role in this giant Carnot cycle engine. They weren't first to suggest this and we haven't heard the last.

MEP at least explains meridional heat exchange and temperature gradients on Mars and Titan where there is no water. Hence it succeeds where M fails as I simply don't believe that M Theory really has a leg to stand on without water/clouds.

This should tell us that we need to look harder to find the real reasons why there may (emphasis may) be, as M suggests, something like a tau/flux 'phase space' in which a Earth's climate system prefers to reside Simplex optimisation-wise - putting aside that is major perturbations which could throw it all out of whack like Milankovitch, comets, gamma ray bursts, bouts of oceanic anoxia 'flu, the dinosaurs all taking up Marlboros and and the like.

Something along the lines of: clouds ± mineral dust ± biogenic aerosols ± salt aerosol ± biogenic albedo/co-albedo ± stripes of MEP current on the ocean (!) etc.

Now if only I was retired. Then I might be able to find the time to have a bash at it. At least it would help to fend off the Alzheimers!

nick as soon as you talk about maximum minimum production of anything at all you are talking about the rate the entity is produced. There is nothing at all new about maximising entropy and I'm sure you'll forgive me if I think ther is a rted involved in dS/dt (t=time)

For example in "Titan, Mars and Earth : Entropy Production by
Latitudinal Heat Transport" Ralph D Lorenz, Jonathan I Lunine, Paul G Withers ( GRL Feb 2012) we have

If the heat flow F (expressed as a power in W,
or a flux in Wm−2 ) flows from a warm reservoir at T0 to
a cool one at T1 (figure 1) the entropy production dS/dt is
simply defined as (F/T -F/T ).

Hat tip to Steve.

# 141 Nick Stokes
“It says nothing about rate….
Again nothing about rates….
Again, nothing said about rates….
refer to equilibrium or end states, not rates….”

So, where does the “maximum rate” come from ?
I can see various steady rate states; (if solids are included)
But in gasses, can you have more than one steady state ?

Nick #139

“In that way it certainly does maximise entropy production.”

Sounds like minimising to me.

It's confusing I know smoother rocks -> nice smoother laminar flow -> water goes from high potential to low potential faster => maximising potential reduction rate => maximising entropy production.

While i don't know if the hypothesis can be generalised and proven for the general case but this one certainly is a case of nature making easier for itself to maximise entropy. Of course we can make use of it a put the water in smooth walled pipes and use the kinetic energy at a lower point to drive a turbine.

Work is done when entropy is increase work is undone (which takes work) when entropy is decreased (think heat pump).

Alex #140
Yes, I do like to use proper names. Otherwise you just get endless confusion. And here we go again.
1. 2LoT is a very well established law. It says irreversible processes always increase total entropy. It says nothing about rate.
2. Maximum entropy production does suggest maximising rate of entropy production. None of its serious proponents claim it is equivalent to 2LoT. Nor do they claim for climate that it is anything but a speculative idea which has some observational support.
3. Principles of minimum energy don't mean literally that, because energy is conserved. They generally mean minimising a form of energy - eg portential energy in your marble case, or often some kind of free energy. Again nothing about rates.
4. Certain variants of free energy minimisation are equivalent to entropy maximisation. Again, nothing said about rates.

Cases 3 and 4 come with strict conditions, which need to be carefully noted. But anyway, as I say they refer to equilibrium or end states, not rates. Where applicable, they are consequences of the laws of physics, including 2LoT (for free energy versions at least).

Nick # 136:

Alright, I'll assume you've forgotten (we've been through this before).

Miskolczi is using the principles of minimum energy (PME) and maximum entropy (MEP) interchangeably.

He first introduces the law in MM2004, p. 234:

Note, that in the boundary layer the principle of energy minimum (or maximum entropy) works toward the thermal equilibrium.

From what I can see, and you're going to hate this with your penchant for properly naming things, but the two laws are really nothing other than restatements of the second law of thermodynamics (2LoT). (Can you not see the title of Ozawa et al. (2003), "The Second Law of Thermodynamics and the Global Climate System: A Review of the Maximum Entropy Production Principle"?)

We had all, back in ClimateAudit, I mean, yourself, Neal J. King & myself, apparently agreed on this much.

Neal wrote to me privately that he might be convinced if I could find a paper that showed any minimum/maximum principle that really restates the second law of thermodynamics, if I could show that it was used to imply a maximum rate.

The classic example of the minimum energy principle is the marble in a bowl. The 2LoT/PME/MEP => that the system will reach a state of minimum energy but, so you've all been saying, says nothing about the rate at which the system moves towards this state. Intuitively, that just doesn't gel for me: I see only a single rate available, and a single minimum energy state, and the former will be necessarily used, and the latter deterministically reached.

At any rate, I then found a PhD thesis from the NASA/Langley site that showed a scientist definitely using the PME to argue that the Sun/Earth system moved to a minimum energy state at a maximum rate. The trouble was, when analysed by Neal & yourself, it was agreed that the science in it was just trash. As such, I wasn't confident that this example proved anything. Next, I found another paper, Huang et al. (2004), that to my mind proved the point in the context of fluid dynamics, but Neal wouldn't accept it, for reasons that, admittedly, I can't remember and probably didn't understand.

You can clearly not use these arguments anymore. There is a rich literature that goes all the way back to the early 19th century with Carnot's heat engine. In the 1960s, Lorenz "suspected that the Earth's atmosphere operates in such a manner as to generate available potential energy at a possible maximum rate."

From what I have been able to gather, therefore, Miskolczi's procedure for maximising Bo in eqn.B11 is essentially just an assumption of 'optimally cooled' is really an assumption of maximised entropy. That is, after all, waht the second law of thermodynamics is all about, is it not, that given time, all systems, and finally, the universe itself, tend over time to a minimum temperature -- and as I said it must be at the maximum available rate! What other path might the universe take towards its ultimate heat death? The same surely with the application of the 2LoT in the case of the global climate system.

Jan #137
"In that way it certainly does maximise entropy production."
Sounds like minimising to me.

Alex #133

I do recall it and also remember that Nick was somewhat confused over the difference between closed and isolated systems

Here

Unfortunately, the Wiki page that you linked is not applicable. The important condition is "at constant entropy". That certainly doesn't work here, with irreversible heat transfer processes. The second law of thermo is not about energy but entropy. It applies to an isolated system, in which energy is generally conserved, not minimised.

Nick #129

But I also agree with Eric that the letters are tossed around here as if they were solidly established laws of physics, while there is a long way to go before they get to this status.

I think there may have been a bit of confusion going on in the general context I initially thought 'MEP' referred to Minimum Energy Principle which is the closed system complement of the Maximum Entropy Principle (for isolated systems) which are both well established statements of the well established second law of thermodynamics.

There also seemed to be some difficulty seeing Maximising Entropy Production as the isolated system's complement of the closed system's maximsing the rate internal energy can be minimisned. I don't think anyone was trying to make out that it was established science - that one is just Arthur's exercising his strawman manufacturing skills picked up on by Eric. You should know better.

Now this is interesting:

This portion of Ozawa’s conclusion seems to reflect the current state of certainty: A possible mechanism by which a turbulent fluid system adjusts itself to a state of MEP is suggested based on the energetic concept of Lorenz.

Whether or not a turbulent fluid system adjusts itself to a state of MEP or it can I don't know but I do know that water flowing over turbulence causing rocks will wear the rough edged off allowing laminar flow over them. In that way it certainly does maximise entropy production.

#134 Alex
The E in Steve's MEP stands for entropy, not energy. They are not the same.

# 133:

Steve, I didn't mean to imply that you were present for the discussions of this at ClimateAudit, sorry, the remark was for Nick, Jan et al., who were there at the time.

To Neal J. King:

If you're still out there, I'd love to hear your comments on the derivation of eqn.B11 now that the MEP literature has been found.

Steve Short, Nick Stokes on MEP:

If anyone is interested in refreshing their memories, the following is a link to the discussion on this that Nick, myself & Neal J. King had a few months ago:

http://www.climateaudit.org/phpBB3/viewtopic.ph...

It is interesting how AGW proponents love to move the goal posts and change the rules play by play. Their new take on the "hot spot" are scripted responses. However, read the following authored by none other than Gavin Schmidt et al.

http://www.osti.gov/energycitations/servlets/pu...
Tropospheric warming is a robust feature of climate model simulations driven by historical increases in greenhouse gases (1–3). Maximum warming is predicted to occur in the middle and upper tropical troposphere.


Their only hope is to play statistical games (Santer et al 2008) and attempt to discredit satellite data. Of course, GISS/HadCRU/NOAA are just fine according to the true believers, but in reality are polished turds.

Oh, and I forgot to say that I think MEP also extends to the actions of a planetary living biomass - if there is one that is. And if that biomass should be primarily photoautotrophic and thus energetically responsive to light flux and CO2, well then........

Ozawa et al. 2003 say:

The hypothesis of the maximum entropy production (MEP) thus far seems to have been dismissed by some as coincidence. The fact that the Earth's climate system transports heat to the same extent as a system in a MEP state does not prove that the Earth's climate system is necessarily seeking such a state. However, the coincidence argument has become harder to sustain now
that Lorenz et al. [2001] have shown that the same condition can reproduce the observed distributions of temperatures and meridional heat fluxes in the atmospheres of Mars and Titan, two celestial bodies with atmospheric conditions and radiative settings very different from those of the Earth. A popular account of this work is given by Lorenz [2001a] and Lorenz [2003].

BTW, getting back to M Theory - has anyone noticed that Ta ~1/6 (which applies to the Earth) and which appears in M's 'transfer function' f(tau) = 2/(1 + tau + exp(-tau)) as the Ta = exp(-tau) term is rather close to the mean (scattering) Aerosol Optical Thickness (tau Aerosol) at 865 - 890 nm of the Earth? Coincidence?

Steve #40
Maybe I am behind the times too, but I do know a little of the origins of MEP. When Garth Paltridge was developing his MEP ideas in atmospheric physics, I was working for the same organisation. It was a time when Prigogine was all the rage, and I'm sure this influenced Garth's ideas. My boss, John Philip, was not at all friendly to these ideas, which restricted my own involvement, but I followed them with interest.

I agree with Steve that the ideas are promising, and have been for many years. Something like that could be said of the related Bayesian concepts. But I also agree with Eric that the letters are tossed around here as if they were solidly established laws of physics, while there is a long way to go before they get to this status.

Currently, MEP is indeed a kind of Bayesian likelihood application in statistical physics. An idea of how restricted its confident application is can be gained from this Wikipedia proviso: "The principle of maximum entropy is useful explicitly only when applied to testable information. A piece of information is testable if it can be determined whether a given distribution is consistent with it." Folks who are fond of talking about MEP might like to think about whether they are included in that.

I've been reading Ozawa et al's review, and I hope to be able to read Klaidon's book. This portion of Ozawa's conclusion seems to reflect the current state of certainty: A possible mechanism by which a turbulent fluid system adjusts itself to a state of MEP is suggested based on the energetic concept of Lorenz. It is hoped that the present attempt will provide an apt starting point for future developments in the studies of thermodynamics and energetics of forced- dissipative systems in general, including our planet

Sorry, but your little mutual admiration clique is way, way behind the times.

MEP theory is a broad field deeply embedded in a long history of study of turbulent and non-equilibrium systems with strong links to Bayesian theory etc.

There would be approaching 40 papers in the MEP field just in the last decade, it has honorable antecedents going back several decades (and in a few cases longer) and those researching it are publishing in mainstream literature on its application in a wide range of systems, including cosmology. It is one of the most fertile field of modern physics.

I suggest you do a bit of Googling and also if possible check out the 2006 review textbook edited by Kleidon and Lorenz (published by Springer).

#125 Eric
"Ad hominem remarks, such as you have made, do not enhance peoples estimation of the substance of your post, which was zero."

Eric ;
You started it -- Do not complain if others reply in kind --Keep on parading your arrogance -- for what purpose ?
Some are here to learn

Arthur,
Good point about scholasticism. There seems to be repetition of certain formulas and principles as an answer to every question, without regard to their applicability.

I had never encounter the idea of Maximum Entropy Production before I read it here. It seems to be used as a fundamental principle of physics underlying every situation.

In fact the authors of the referenced article, view it as one of a number of different possible principles which could describe climate depending on the circumstances.

http://www.lpl.arizona.edu/~rlorenz/entropy.pdf

"Using zonal energy-balance models, several workers have
demonstrated [Paltridge, 1975], [Wyant et al., 1988] [Grassl,
1990] that the Earth's climate seems to be in this maximum
entropy production state.
It is not clear why the system should `choose' this state:
however, ideas in nonlinear dynamics suggest that this state
is natural for complex systems. While a fluid system with
xed boundary conditions will minimize its entropy production,
one with adequate degrees of freedom (like a suciently
thick planetary atmosphere) can instead adjust the boundary
conditions and the internal flows to maximize this quantity"

The language here is tentative. Use of the words, "seems" , "suggest" indicate this. Some systems minimize the entropy production. MEP is suggested as a means of shedding light on the behavior of systems where it appears to apply, rather than a prescription for what will happen.

You wouldn't know it from the posts of those who keep throwing the letters MEP around at every opportunity, as if it were a fundamental principle of how things worked.

Franko // Nov 20, 2008 at 5:53 pm
says,
"#121 Eric

““The reason in the temperature is not bounded””
“What is the reason for the restriction?“
“Venus has a huge vertical temperature gradient, and the top of its atmosphere is way colder than earth.”

Why is Venus heat engine so inefficient ?

“This explains why no one except AGW sceptics are paying attention.”

Your delusional, self-hypnotic, immersed in a culture of mob action, debate is over; time to Spanish Inquisition the Heretics attitude – can you see it ?"

If you believe and understand M's stuff, I would appreciate an answer to the question about the derivation of the formula in post 121. It appears to be unclear to many people who know a lot of physics, including myself.
The writing is not clear. Maybe people who claim to understand the stuff
could answer my question. It is a logical scientific question.
I don't need to apologize for asking. Anyone who has had real scientific training would ask such questions. I thought the purpose of this web site was to engage in such discussions.

If you can't answer the question so be it. I am not putting you on the rack or condemning you to death for not doing so, so the spanish inquisition is not an appropriate parallel.

Ad hominem remarks, such as you have made, do not enhance peoples estimation of the substance of your post, which was zero.

#122 Arthur Smith

"the discussions by his followers seem to be almost complete scientific nonsense."

People are learning, building, exploring theories;
Sand Castles of "scientific nonsense" ?
Can Arthur Smith provide a better, simpler more accurate theory ?

#121 Eric

““The reason in the temperature is not bounded””
“What is the reason for the restriction?“
“Venus has a huge vertical temperature gradient, and the top of its atmosphere is way colder than earth.”

Why is Venus heat engine so inefficient ?

“This explains why no one except AGW sceptics are paying attention.”

Your delusional, self-hypnotic, immersed in a culture of mob action, debate is over; time to Spanish Inquisition the Heretics attitude – can you see it ?

Eric - the attitude to Miscolczi's theory by Jan, David, perhaps Alex, and some of the others here reminds me of medieval scholasticism and Aristotle. True science is based on understanding, independent replication of results through different approaches, a web of interlocking logic. Scholasticism, in contrast, is based on peculiar interpretation of texts from great minds that are believed infallible - if something in nature disagrees with the text, well, we have just misinterpreted the text a little. But in real science, if a text is subject to such misinterpretations, its worth is greatly diminished. Real science depends on extreme clarity of presentation - the technical language sometimes gets in the way of clarity to the uninitiated, but the purpose of the technical jargon is not to obfuscate, but to be precise: every term must have a precise definition and context. Miscolczi's articles are an example of poorly presented but still real science; the discussions by his followers seem to be almost complete scientific nonsense.

118 David Stockwell // Nov 20, 2008 at 6:44 am

"As for Venus, I think it is adequately explained by the Eddington -Milne equation, where the temperature B increases linearly witih τ the optical depth increases: B(τ)=H(1+τ)/2

The reason in the temperature is not bounded, is that unlike on earth, the atmosphere is too deep for the energetic constraint Su=1.5*OLR to apply."

Where in the derivation (if there is one), of Su=1.5*OLR, in Mikolczi's paper, is the condition for optical depth of the atmosphere stated ?
What is the reason for the restriction?
Without this knowledge, it would appear that Venus is a good counterexample for a theory that the greenhouse effect is limited, which destroys its credibility.

Venus has a huge vertical temperature gradient, and the top of its atmosphere is way colder than earth.

M's theory is quite counterintuitive, so it has a heavy burden of proof.
The equations used for the constraints seem not to apply to radiation in the way that Mikolczi uses them. The fact that they agree with conditions in a case or 2 at a given point in time, does not logically imply that they are universal, especially since a counter example is available.

This explains why no one except AGW sceptics are paying attention.

Steve #119

Now if only we could re-examine the Misckolczi formalism according to MEP……

Should be possible they are reading different pages from the same book.

Franko#117

"Is this a contradiction ? — Zagoni;
” Earth’s greenhouse effect is working at its energetic top; further greenhouse warming is practically impossible;”

Exactly, listen to this stuff:

Zagoni : 'working at its energetic top'
Miskolczi: 'the system is locked to the tauA optical depth because the energy minimum principle prefers the radiative equilibrium configuration (tauAtauAzero).'

Come on. This is potentially (pun intended) a decent theory, and I suspect the math is broadly correct. But dammit, the explanations/reasons given range from abysmal to totally opaque (again pun intended) so it could well, at least in part, be a case of right for the wrong or meaningless reasons.

In a nutshell M suggests that if the atmosphere or climate has an additional integral invariant, one may expect that changes in one part of the atmosphere will be compensated for by changes in other parts of the atmosphere. A lot of evidence suggests this is essentially a sound principle.

A good candidate for such an additional "invariant" does indeed exist and its the "Principle of Maximum Entropy Production (MEP). MEP correctly predicts the magnitude of the convective latitudinal heat-transfer rate by winds on Earth, Mars, and Titan:

http://www.lpl.arizona.edu/~rlorenz/entropy.pdf

and almost perfectly reproduces the terrestrial observed dry tropospheric temperature profile:

http://www.knmi.nl/publications/showAbstract.ph...

Now if only we could re-examine the Misckolczi formalism according to MEP......

As for Venus, I think it is adequately explained by the Eddington -Milne equation, where the temperature B increases linearly witih τ the optical depth increases: B(τ)=H(1+τ)/2

The reason ithe temperature is not bounded, is that unlike on earth, the atmosphere is too deep for the energetic constraint Su=1.5*OLR to apply.

<abbr>David Stockwells last blog post..Another American Thinker Walks</abbr>

Is this a contradiction ? --- Zagoni;
" Earth’s greenhouse effect is working at its energetic top; further greenhouse warming is practically impossible;"

"The LW heating effect ... of clouds ... is almost the same as closing the atmospheric IR window"

Not only gasses, but also clouds are included ?

Venus, with complete cloud cover, closes more than the IR window ? Impedes convection ?

Eric

"The surface of Venus is made very hot as a result of its atmospheric greenhouse effect."

Aye? If the sun can't reach to the bottom and atmospheres are warmed from the bottom up, just exactly how is this supposed to work?

H2O, on Earth, reduces density, and aids the convection engine. Condenses at the tropopause, falls out. Increasing density of the air, to fall down.

Venus SO2, H2SO4, at the surface, increase density, need higher temperature to convect up. Once condensed out, the remaining gas becomes lighter, Brakes the heat engine, both up and down.

Eric#112

"...density and temperature are independent variables that are not intrinsically related by any physical principles I know about."

Boom boom!

Thus spake Zaratrustme

# 112 Eric
"density and temperature are independent variables that are not intrinsically related by any physical principles I know about"

4C densest at the bottom of a frozen lake. Convection stalled, untill more heat. Temperature, but not density inversion. Takes high temperature, (and sometimes, chemical reactions, phase changes), to break out of the density prision, Inside the Earth needs to be very hot to let the gasses out.

H2SO4, SO2 percolate from Venus volcanoes, to the tropopause. Faster than the lava and magma, but still slow ?

Franko said, // Nov 20, 2008 at 2:32 am

# 107Eric
“How do you explain the temperature of venus ?”

Density, not temperature rules
On Earth, the tropopauser is H2O=18
On Venus the tropopauser is H2SO4=98

On Earth the tropopauser is considerably lighter
On Venus, considerably heavier

Earth, beneath the surface, is very hot, because it is density contained. Above colder, because, gravity abhors a density inversion"

Franko,

This explanation doesn't make sense based on any principles of physics I understand or have ever encountered before.

A density and temperature are independent variables that are not intrinsically related by any physical principles I know about. An object can be hot or cold regardless of its molecular weight, unless decomposition occurs, but you aren't making that argument.

The surface of Venus is made very hot as a result of its atmospheric greenhouse effect.

Only a tiny portion of the radiation from the hot surface escapes due to the absorption by the dense atmosphere which has enormously high opacity.
60% of the incoming radiation from the sun is reflected , is reflected by sulfate clouds, and doesn't even enter the lower part of the atmosphere. Despite that the surface has to get very hot to maintain the planet's energy balance because so little radiation is allowed to escape.

The answer is a combination of an atmosphere that is almost 100% IR absorbing gases, and the density of these absorbing gases is high. If the gases could not absorb IR, the high density by itself would not be sufficient to warm the planet.

The high temperatures on Venus are a result of the atmospheric greenhouse effect, and show that the effect is not intrinsically limited by certain principles of physics as Mikolczi claims.

jae #109
"And as I understand it, that’s EXACTLY what Miskolczi did! AND THEN he demonstrated it empirically."
No, you've got that wrong. In his published paper, he claimed it as a theoretical result - his Eq (8), based on a universal principle of energy conservation. When exceptions were pointed out, he qualified that to "partly cloudy" atmospheres (is this apparatus a partly cloudy atmosphere?).

Later, on a website appeared a plot showing (I believe) correlations from LBL calculations. AFAIK that's as empirical as it gets - I've seen no evidence of this from FM based on radiative flux measurements.

# 107Eric
"How do you explain the temperature of venus ?"

Density, not temperature rules
On Earth, the tropopauser is H2O=18
On Venus the tropopauser is H2SO4=98

On Earth the tropopauser is considerably lighter
On Venus, considerably heavier

Earth, beneath the surface, is very hot, because it is density contained. Above colder, because, gravity abhors a density inversion

Nick:

"The 1.5 factor is a FM special. There’s no corresponding limit in standard theory. You just have to measure or compute with a LBL-type code."

And as I understand it, that's EXACTLY what Miskolczi did! AND THEN he demonstrated it empirically. What it your point? What else do you want to show that the "standard theory" is trash?

David #106
The steel greenhouse model assumes total opacity. Realistically, for the Earth you can't go on adding new layers with new material. You can consider dividing existing GHG's among more and more layers of finite and diminishing opacity. And that's one computational way of getting to the continuum limit. But it doesn't imply unbounded increase.

The 1.5 factor is a FM special. There's no corresponding limit in standard theory. You just have to measure or compute with a LBL-type code.

How do you explain the temperature of venus? Very little solar radiation penetrates the upper atmosphere clouds but the surface temperature is over 700C.
The actual factor for earth is about 1.6 which is more than 1.5 already.
The equations used to set constraints on the greenhouse effect are inappropriate and not justifiable, so the theory is not on a sound footing in the first place.

The temperature rise due to an atmospheric layer the depth of your bottle is in the neighborhood of 0.017C if adding water doubles the humidity originally present.
The emissivity of the small amount of air in your bottle is about 0.0001.

#105. Even if you regard it qualitatively, the RC model predicts temperatures will increase unboundedly as you add more layers. This distinguishes it from FMs equation that predicts a maximum GE of 1.5 nomatter how many layers.

<abbr>David Stockwells last blog post..Another American Thinker Walks</abbr>

David #95
I guess I have to take issue again with this silly and misleading claim that there is a "standard RC model" predicting a GE maximum of 2.0. They gave the very simplest standard configuration in which IR obstruction can raise temperatures. It was full of caveats to indicate that it was not a real model of the atmosphere. See my posts 3,8,10 above.

Alex has now pointed to a textbook which gives the same example with similar caveats. They point out, as I did in #8, that if you assume two layers you get a factor of 3.0 etc. Of course, that is for opaque layers; if you split a finite amount of GHG among more layers, each layer becomes less opaque. But anyway, the clear message is that there is no meaningful GE ratio in this example.

Arthur Smith #90 chants:

"Folks - whether or not it exists, the “tropospheric hot spot” has no relation to warming from greenhouse gases, it is present for any source of warming, including solar, in the models"

Please read your own statement Arthur. "it is present for ANY source of warming." And YES, the IPCC does say it is present for GHG warming ALSO.

Please think about that. If the hot spot is present for ANY source of warming, it will be present for GHG warming. Conversely it will NOT be present if there is NO warming.

In other words, if we are to believe the models, there is currently NO WARMING!!! The satellite and other observations support this. So, which is it. Are the models wrong or right? If they are right there is no warming. If they are wrong, the observations STILL show no warming.

HAHAHAHAHAHAHAHAHAHAHAHAHA

Of course, the models could just be wrong about MAGNITUDE, in which case there is STILL no problem other than what the warmers are causing!!

This is a very silly mantra that you warmers have picked up. Very illogical. I don't understand how you could have been tricked into making the claim!! If I, as an ignorant denier, had tried to convince you of this even a year ago you would have torched me. Now you make the claim of no warming on your own!!!

Welcome to Denial Land!!

Eric:

"Tell me where I have gone wrong."

Maybe you need to take a valium, sit back, re-read, and rethink the experiment. You got way off-target in your thinking, methinks.

I do have a copy though my institution library. I don't have a link. And no I'm not going to post it anywhere for you. Next time look before you leap.

Heil Lindzen, Spencer, Pjelke, McIntyre, .....

The air temperature was probably not measured correctly and solar heating of the solid parts of the experiment accounts for the temperature in your container. The thermometer sitting in the sun will not actually measure the air temperature.

Who said anything about measuring air temperature? The sensor is in contact with the internal black body as a proxy for Su, the radiation/temperature of the earth. As you state, the air inside will eventually come to equilibrium based on the heating of the walls of the container. So what is your concern. I think you are getting closer. Do the analysis. Make a prediction.

98 Steve Short // Nov 19, 2008 at 7:58 pm
said,
"Eric #96

“You gave an example of a researcher who relied on the original analysis of the data by Spencer and Christy, and believed that the fault was in the models.”

This an outrageously untrue statement and a total strawman. Kleidon is an expert practitioner of GCMs. He just happens to be a leading researcher in MEP as well. His paper didn’t ‘use’ and doesn’t even reference Spencer and Christy!

You obviously hadn’t a clue what I was talking about which was the actual way modern GCMs are structured in terms of meridional energy exchange.

I’m so tired of these old AGW stormtroopers. The ‘line’ is always the same, get up, pull on the jackboots and go out stomping and re-stomping over all the old stuff."

Not having read the entire paper, I assumed Kleidon was talking about the
tropical tropospherical hot spot somewhere in it. Reading the excerpt, it was simply a criticism of GCM's overestimating the temperature gradient between the tropics and the poles. It did not speak to the vertical temperature profile in the tropics. If you have a link, I am interested in reading it.

Heil Hansen!

admin says
// Nov 19, 2008 at 6:11 pm

"Eric, the game is for you to tell us, and then to reveal the results of the experiment to see if you know what you are talking about. Do the calculations using the standard RealClimate model (2 times ambient) and Miskolczi’s model (1.5 times ambient). Do the calculation with an other layer. Is it 2 times two or 1.5 times 1.5 or what? State the principles you think are operating. I will reveal the results and what I think in time."

As I pointed out, you didn't account for the flaws in your experiment.
The air temperature was probably not measured correctly and solar heating of the solid parts of the experiment accounts for the temperature in your container. The results will have nothing to do with the real climate model versus Miskolczi models of greenhouse gas absorption. The air inside will eventually come to equilibrium based on the heating of the walls of the container. That is according to the laws of thermodynamics.
It can't get any hotter than that, because the container wall is absorbing and emitting radiation much at a much greater rate than the air in the container, so its equilibrium with the fixed sources of radiation will determine the temperature. The air inside has very little heat capacity and low emissivity.
It takes 10,000 meters of air to absorb all of the upwelling radiation in the
IR spectrum excluding the IR window. The air inside will absorb a tiny fraction of the IR radiation from its environment in its band, only about 1/10000 if it is as much as 1 meter thick.
The glass container has an IR emissivity of about 0.84, and the thermometer, being black has an emissivity closer to 1 for solar radiation will heat up to a higher temperature than the glass, and I don't know the emissivity of the material underneath the apparatus. These will dominate the heat transfer equations. The thermometer sitting in the sun will not actually measure the air temperature.

Those are my thoughts.
Tell me where I have gone wrong.

Eric #96

"You gave an example of a researcher who relied on the original analysis of the data by Spencer and Christy, and believed that the fault was in the models."

This an outrageously untrue statement and a total strawman. Kleidon is an expert practitioner of GCMs. He just happens to be a leading researcher in MEP as well. His paper didn't 'use' and doesn't even reference Spencer and Christy!

You obviously hadn't a clue what I was talking about which was the actual way modern GCMs are structured in terms of meridional energy exchange.

I'm so tired of these old AGW stormtroopers. The 'line' is always the same, get up, pull on the jackboots and go out stomping and re-stomping over all the old stuff.

Eric: You are cherry-picking papers. When I get time, I'll prove it.

89 Steve Short // Nov 19, 2008 at 10:59 am


You gave an example of a researcher who relied on the original analysis of the data by Spencer and Christy, and believed that the fault was in the models.
Others criticized the analysis of the satellite data, which has signals from different atmospheric layers mixed in and requires sophisticated analysis to make temperature versus depth calculations.
The following article showed a flaw that caused Christy to agree to correct his data somewhat.

http://www.newscientist.com/article/mg18725134....
AS NAILS in the coffin go, they don't get much bigger: three independent studies have shown that climate sceptics who claim that Earth is not warming have been using faulty data to make their point.

"Now Carl Mears and Frank Wentz of Remote Sensing Systems in Santa Rosa, California, have an answer. They reanalysed Christy's data and corrected for errors caused by satellite drift. "The satellite is supposed to go over the equator and take measurements at the same time every day," says Mears. Initially this was at around 2 pm local time, but after a few years it was crossing the equator at 5 pm, he says. "Common sense tells you that it's cooler at 5 pm than at 2 pm, and that was biasing the results." Once they factored this in, the data showed that the troposphere is warming (Science, DOI: 10.1126/science.1114772)."

This article was published in 2005. Since then more work has been done to show that the hot spot at 200hPa in the tropical troposphere is present in the data.
http://www.realclimate.org/images/santer_etal08...

Eric, the game is for you to tell us, and then to reveal the results of the experiment to see if you know what you are talking about. Do the calculations using the standard RealClimate model (2 times ambient) and Miskolczi's model (1.5 times ambient). Do the calculation with an other layer. Is it 2 times two or 1.5 times 1.5 or what? State the principles you think are operating. I will reveal the results and what I think in time.

Eric: maybe the experiment is telling us that water is a negative feedback in the system?

Admin still hasn't aswered the question of how much temperature change is expected by the standard model of GHG warming, and the Miskolczi, in his experiment, and whether, his measurement system could detect the difference.

That is the original subject of this thread, and determines whether his simple home experiment can tell us anything.

Hell, there has been no global warming at ANY level in about 10 years, and the models are so far off that they are becoming ridiculous. Face it, there is absolutely no evidence, theoretical or empirical, that CO2 is causing a warming of this planet.

Geoff#75

"This observation impinges on questions of whether there should or should not be a land/air temperature discontinuity at a scale of close examination of detail and include factors such as relative humidity, night/day changes etc."

We have discussed this on NM before. We know that for over 30 years potential evaporation (Ep; pan evaporation) has be trending downwards on the continents. Most recently this was ascribed in a review to a downward trend in continental wind speeds (not vectors) of about -0.010 m/s/y. No trends in VPD (i.e. RH) or air temperature were sufficient to cause the downward Ep trend.

This situation does not match with oceanic wind speeds where the data indicate an upward trend of about +0.008 m/s/y.

Folks - whether or not it exists, the "tropospheric hot spot" has no relation to warming from greenhouse gases, it is present for any source of warming, including solar, in the models. Stratospheric cooling is the characteristic signature of greenhouse gases - if the warming is from the sun, the stratosphere warms along with the troposphere, but not so for greenhouse gases.

Eric #85

"The hotspot is now believed to exist by most everyone except Spencer and Christie, and their followers. The hotspot in the model has nothing to do with AGW. It is a feature expected from calculating the lapse rate of a moist adiabat in the tropics."

Bollocks.

For some years now it has also been 'believed' by a number of sophisticated modelers that the hotspot was probably simply a function of thermodynamic deficiencies in the GCM themselves which were used to predict the beastie.

"Energy balance models suggest that the atmospheric circulation operates close to a state of maximum entropy production. Here we support this hypothesis with sensitivity simulations of an atmospheric general circulation model. A state of maximum entropy production is obtained by (i) adjusting boundary layer turbulence and (ii) using a sufficiently high model resolution which allows sufficient degrees of freedom for the atmospheric flow. The state of maximum entropy production is associated with the largest conversion of available potential energy into kinetic energy which is subsequently dissipated by boundary layer turbulence. It exhibits the largest eddy activity in the mid latitudes, resulting in the most effective transport of heat towards the poles and the least equator-pole temperature difference. These results suggest that GCMs have a fundamental tendency to underestimate the magnitude of atmospheric heat transport and, therefore, overestimate the equator-pole temperature gradient for the present-day climate, for the response to global climatic change, and for atmospheres of other planetary bodies."

Kleidon et al. Geophys. Res. Lett. 30(23), 2223 (2003)

Eric at 86 says;

"The hotspot is now believed to exist by most everyone except Spencer and Christie, and their followers."

I just love it when the word "believe" enters a scientific debate; at law belief is a mitigator of guilt which has nothing to do with the fact but is to do with whether the defendant had the capacity to understand the reality of what was done; exculpation accrues to the insane and partially to the self-defenders; I wonder which defence the AGW supporters will use. Anyway Eric, here are some troposphere temperature graphs; show us where the THS is;

http://www.junkscience.com/MSU_Temps/UAHMSUglob...

http://www.junkscience.com/MSU_Temps/RSSglobe.html

#80 Arthur Smith - small comment

You write "The temperature gradient is about 20 K/km in the crust, leading to temperatures of 500 C or more at the mantle boundary (and 4000 C at the core). Blackbody radiation at 500 C would be over 20,000 W/m^2, for a G ratio of 20,000+. Essentially, arbitrarily high."

The Kola superdeep drill hole in Russia was stopped at 12,200 m depth because the rock temperature was too high. It was 205 deg C, roughly a gradient of 15 deg per km. The geothermal gradient is too variable from place to place for easy generalisation. Its variability is a (small) source of error in the global heat flow equation. Moreover, it is not a steady gradient with depth, but a wobbly one, unsuited to model extrapolation. In some locations, some in Japan, it can reach about 80 deg per km. The Warrego Mine at Tennant Creek, in the middle of the continent, in very old rocks, had a troublesome, high geothermal gradient for no reson we could imagine. At sea floor spreading centres the figure can be in the hundreds of deg per km.

Jae,
If you look at K and T's paper, http://www.atmo.arizona.edu/students/courselink...
you can see in figure 5 a list of estimates of the earth's radiation budget by 13 different authors. The one by OB, chosen in the entropy paper shows the lowest value of LW, which is the net upward long wave radiation of the 13, at 40.
The highest value given is 72.
K&H 1996 paper gives a value of 66.
The value of SH, the convection number ranges from 16 to 24.

Cohenite Says,

"62 & 80. A THS is a Troposphere Hot Spot, expected to occur in the Tropics due to AGW. Arthur has referred to FIG 9.1 of AR4, and notes that “Stratospheric cooling combined with tropospheric warming is the signature effect of greenhouse gas increases;”; well FIG 9.1(c) shows the modelled THS; numerous IPCC authors have tried to verify it; Sherwood and Allen had a memorable attempt, and Santer is the latest windmill tilter; it doesn’t exist."

NASA produced a consensus document making correction to the UAH data which at one time found the lack of a hotspot in the upper tropical troposphere. The hotspot is now believed to exist by most everyone except Spencer and Christie, and their followers. The hotspot in the model has nothing to do with AGW. It is a feature expected from calculating the lapse rate of a moist adiabat in the tropics.

Jae,
Ok I see what you are talking about.
The author gives a figure of 40W/M2 for radiation, and 100W/M2 for the combination of convection and latent heat of vaporization.
Trenberth shows 24 W/M^2 for convection + 78W/M^2 for vaporization of water= 102.
So to be accurate, it is transpiration that contributes the largest net amount of heat from the atmosphere and the difference between upward and downward radiation is second. That order is the same as in Trenberth's paper, but the actual figure for radiation is 26W/M^2 larger.
The paper you linked shows older references for the numbers:

"The values in the brackets represent the globalmean
energy fluxes (W m2) based on global surface
radiation measurements [Ohmura and Gilgen, 1993] and
satellite measurements [Barkstrom et al., 1990]."

The paper quoted by everyone else was Kiehl and Trenberth, 1996.

62 & 80. A THS is a Troposphere Hot Spot, expected to occur in the Tropics due to AGW. Arthur has referred to FIG 9.1 of AR4, and notes that "Stratospheric cooling combined with tropospheric warming is the signature effect of greenhouse gas increases;"; well FIG 9.1(c) shows the modelled THS; numerous IPCC authors have tried to verify it; Sherwood and Allen had a memorable attempt, and Santer is the latest windmill tilter; it doesn't exist. As for Stratosphere cooling (SC);

http://junkscience.com/MSU_Temps/Stratosphere12...

The graph shows the warming effect in the lower stratopshere from El Chichon and Pinatubo; this is consistent with the theory that volcanic particulate absorb the high energy wavelength; the graph then shows a drastic dropping off supposedly consistent with the resumption of AGW. But the likely duration of volcanic effect is 7-9 years and the large amounts of erupted SO2 are known to destroy ozone. The ozone depletion is well documented and the Stratopheric temperatures are trending upward after 7 or so years. As a fingerprint SC leaves a lot to be desired.

uh, make that 'writes', not 'rights'. Duuh. It's late here.

"Does Miskolzci give a reference for his statement that contains the measurements to support what he says?"

Yes read the paper.

"It seems that he isn’t aware of these results, based on his statement."

Whose? The ones based on his own work done while calibrating the satellite data that people like K &T used? Or K&Ts based on the artificial and nowhere supported by empirical measurement USST76 profile?

I'm sure he's aware of the former having looked at thousands of radiosonde profiles and satellite data. The latter he say's why they are wrong on page 20

In Kiehl and Trenberth (1997) the USST-76 atmosphere was used for the estimation of the clear-sky global mean $$E_D$$ and OLR. To make their computed OLR consistent with the ERBE clear-sky observations, they reduced the tropospheric water vapor amount by 12%, to about 1.26prcm.

JamesG - Greenhouse gases directly cause cooling of the stratosphere, because more GHG's increase the emitted flux from any given region, and the stratosphere is where there is no balancing "back-radiation" from further out to slow down the net radiative loss. This is discussed to some extent in Chapter 9 of IPCC AR4 WG1 - see p. 674 - "cooling in
the stratosphere [...] results predominantly from greenhouse gas
and stratospheric ozone forcing (Figure 9.1f)" - and you can see the detailed effects from the (slightly famous) figure 9.1. Stratospheric cooling combined with tropospheric warming is the signature effect of greenhouse gas increases. The ozone depletion contribution to stratospheric cooling is, from this figure 9.1, primarily in the lower stratosphere near the poles.

David's experiment here is somewhat like the stratospheric situation because he has a local region with considerably higher temperature than the surroundings - however, added GHG's will result in cooling only if they significantly increase the effective radiating area - a very small effect I think here. In any case, you need a large temperature differential across the system containing the infrared absorbers to get the warming effect, and that's not happening in this experiment.

"Admin" rights:

The standard theory predicts a considerable discontinuity at the surface in the global average temperature, which does not occur.

- but I thought people were arguing there was no such things as a global average temperature, anyway? :-) I really don't know the observational or theoretical basis for these claims one way or another, but it seems reasonable to me that there could be a discontinuity due to the physical material boundary, and the fact that you are admitting it to be continuous only in an averaged sense is even more evidence that this has nothing to do with local thermodynamic equilibrium.

Admin also rights

The greenhouse factor G being looked at G is a ratio OLR/Su or Tearth/Tblackbody if you like. The Tblackbody is a product of certain flux level, heat or radiation. The Tearth or Tgreenhouse is a result of that same flux level entering into a bandpass diode-like enclosure . The flux can’t be arbitrary, but must be the same as the background of the apparatus.

- I am saying that Tearth/Tblackbody can be arbitrarily large (though there is an ultimate limit on Tearth - it must be less than the spectral temperature of the incoming radiation, in the case of an incoming flux from radiation - 5000 K or so in the case of the Sun). Of course Tblackbody can be calculated when you measure the incoming instantaneous radiation level (in W/m^2) from the Stefan-Boltzmann law. It has little to do with the "background" temperature if by that you mean the ambient temperature of the air, since that is significantly cooled by nonradiative means. For 1000 W/m^2, typical of noon-time clear-sky sunlight if you're not too far from the equator, Stefan-Boltzmann gives you 364 K, or about 90 degrees C.

That T_blackbody is the temperature you would reach if your system transfers heat with its surroundings only through radiation, and if those surroundings are not radiating themselves (a cold vacuum enclosure). With warmer surroundings the equilibrated temperature will be a little higher - if you're getting 1000 W/m^2 from the sun and 330 W/m^2 from the surroundings, the effective T_blackbody bumps up to 391 K or about 118 degrees C.

This is also under an assumption that the radiating surface is identical with the surface receiving incoming radiation - in your experiment that's actually not true, and you have to cut the incoming solar flux by some factor, perhaps in half, because the sunlight only hits one side of your absorber, not both (it may be even less depending on the geometry of your system). That gives an incoming solar rate of, say, 500 W/m^2 (half the incoming), plus the 330 W/m^2 from surroundings, for about 347 K, or 74 C Tblackbody.

In any case you can calculate what the actual blackbody temperature relevant for your system is from the setup and a measurement of incoming sunlight, you don't have to guess it (and it is required only to be larger than the ambient surrounding temperature).

Of course as Nick has pointed out, the actual GHG effect in your system is negligible, so the ratio G that you get should be very close to 1 (or less than 1, if you have heat leaking out some other way).

But in a real experimental test of the atmospheric greenhouse effect, such as the solid-state version I proposed (I think differing types of glass with differing infrared properties would work, and perhaps for best simulation of Earth the geometry should be spherical?) G can grow as big as you like.

In fact, we already have something of an experiment of this sort going on in Earth's interior right now. Infrared absorption is only one of the factors limiting heat flow from the center of the Earth to the surface; conduction is the primary heat flow mechanism near the surface . But the net heat flow rate (from radioactive decay as the source) is well under 1 W/m^2 so blocking of the infrared radiation is clearly necessary. The temperature gradient is about 20 K/km in the crust, leading to temperatures of 500 C or more at the mantle boundary (and 4000 C at the core). Blackbody radiation at 500 C would be over 20,000 W/m^2, for a G ratio of 20,000+. Essentially, arbitrarily high.

74 jae // Nov 19, 2008 at 12:10 am

eric and arthur: you might want to look at this paper, too. It also demonstrates that convection is far more important in transferring heat from the surface than is radiation: http://www.lpl.arizona.edu/~rlorenz/MEPRG.pdf

Where does it say that in the paper?
The paper is a treatise showing that the principle of maximum possible rate of entropy increase is a way of understanding the General Circulation models of planetary atmospheres. It spends a lot of time on wind currents because of the conversion of their mechanical energy into heat energy is the means by which entropy increases. I can't find anything in the paper that says what you claim it says.

Jan Pompe says
// Nov 19, 2008 at 12:03 am

"Eric #69

Measurements say the average upward radiation flux from the earth’s surface is 390W/M2, way more than the average energy conveyed by convection. If are quoting Miscolzci it shows he is full of sh–. As any scientist knows the results of measurements are the last word, assuming they are done properly.

Are you sure you understand what is being said? Miskolczi’s paper says that a large portion of that 390w is compensated by downward atmospheric radiation so that the bulk of transport of heat is convective. It is a measured result. He states it specifically in the paper and that a study of convective transport (K) was beyond the scope of the paper (p26)."

According to Trenberth's figures even the net upward radiation into the atmosphere after subtraction of the atmospheric down welling is 66W/M2.
That is much larger than the 24W/M2 for convection given by Trenberth.
Does Miskolzci give a reference for his statement that contains the measurements to support what he says? It seems that he isn't aware of these results, based on his statement. But as you say, he doesn't claim expertise on convective transport in his paper.

Geoff:

"Some evaporation, latent heat etc happens at these depths and the consequences can be but slowly transported to surface measurements. This observation impinges on questions of whether there should or should not be a land/air temperature discontinuity at a scale of close examination of detail and include factors such as relative humidity, night/day changes etc."

It appears that the humid areas on land have the same absolute humidities as the ocean areas, on average of 30 years. The vegetation evidently takes care of this seeming inconsistency, by pulling that water out of the soil/water table and giving it to the air. ALL humid areas have an absolute humidity that is relatively close to (75% or so) saturation absolute humidity (on average over 30 years). It is the same as the tropics, where there is no shortage of water. See here, Hotterdryer.xls, figure 1. http://www.esnips.com/web/climate

Geoff #75
You're right about sparse atmospheres - that's exactly when LTE doesn't apply. It's a measure of non-sparsity. It's often described as a condition for temperature to be defined. Another version - there is just one temperature for all molecules (in a local region).

#60 Nick

You write "They absorb IR as individual molecules, but the heat immediately becomes a property of the gas mixture locally."

I am questioning this. It seems more likely to me that most heat acts on the major local gas mixture before the GHGs get a look in. I also think we are generalising too much about the relative process speeds of molecular absorption, kinetic transfer etc especially in sparse atmospheres and the difficulties of using thermometry to explain them (as say, opposed to spectroscopy/photon counting). I'll cogitate some more.

Meantime, if Admin does not object, or if there is interest in a new thread, I would like to mention some absurd generalisations of the Uncerainty Principle to everyday TV life and to note that the term "black body radiation" is heading in the same direction. It would be interesting to set a time and date for contributors to post a half dozen paragraphs on their understanding of black body radiation and its context in climate. I suspect that a comparison of responses would show enough diversity to need correction.

In this fruit-salad post here, I would also note that the near surface climate processes on land are being generalised too much. Many land areas have water tables that can be many metres down. Some evaporation, latent heat etc happens at these depths and the consequences can be but slowly transported to surface measurements. This observation impinges on questions of whether there should or should not be a land/air temperature discontinuity at a scale of close examination of detail and include factors such as relative humidity, night/day changes etc.

On a related topic, it is hardly fair to talk without qualifiers about surface sea temperatures when the temperature gradient in the sea varies so much with depth.

Sorry for the omnibus.

eric and arthur: you might want to look at this paper, too. It also demonstrates that convection is far more important in transferring heat from the surface than is radiation: http://www.lpl.arizona.edu/~rlorenz/MEPRG.pdf

Eric:

I could probably say that you are deceiving yourself on only one count, that is absolute, positive, belief in the KT radiation cartoon. :)

Eric #69

Measurements say the average upward radiation flux from the earth’s surface is 390W/M2, way more than the average energy conveyed by convection. If are quoting Miscolzci it shows he is full of sh–. As any scientist knows the results of measurements are the last word, assuming they are done properly.

Are you sure you understand what is being said? Miskolczi's paper says that a large portion of that 390w is compensated by downward atmospheric radiation so that the bulk of transport of heat is convective. It is a measured result. He states it specifically in the paper and that a study of convective transport (K) was beyond the scope of the paper (p26).

Radiation however is the only way that the earth can get rid of it's heat and that is the process that he has been studying ( and calibrating the instruments that measure it ) for the past 30 years.

Arthur #63

More on “discontinuity in temperatures at the surface” - in general, the temperature of the air (a few feet) above water can be quite different from the water temperature: if you don’t believe this, I challenge you to a swim in the Atlantic on a warm day in March!

Yes indeed and the diurnal cycle is a heat engine that pushes day sailors out to sea in the morning and back to shore in the evening. It's the average over the day the year etc. that creates the static model that this equilibrium between surface and atmosphere is seen.

jae // Nov 18, 2008 at 4:52 pm 65

"Arthur, you say:

“How would you get precise numbers on the average convective heat flux? Looking at a climate model’s convection would be a good place to start - in fact, I believe that’s what the Kiehl-Trenberth diagram is based on. Feel free to suggest a better way to measure or estimate it!”

I don’t know how to estimate the total effect of convection, but it’s got to be more than 24 wm-2. The temperature difference between the outside and inside of a greenhouse proves that to me, as I said before. All that extra heat is removed by convection. I think that Miskolczi says that virtually ALL energy from the surface is transferred to the atmosphere by non-radiative means (convection, latent heat). I think that is right. As any engineer knows, thermal radiation is a very poor way to get rid of heat. And Mother Nature is at least as smart as the engineers. :)"

Why should we care about what Miskolzci says?
Measurements say the average upward radiation flux from the earth's surface is 390W/M2, way more than the average energy conveyed by convection. If are quoting Miscolzci it shows he is full of sh--. As any scientist knows the results of measurements are the last word, assuming they are done properly.

You are deceiving yourself on 2 counts.
1) The convection is higher than 24W/M2 during the day time so the greenhouse gets significantly warmer at that time.
2) The net LW radiation lost to the atmosphere, after you subtract the downwelling from the upward radiation is actually about 65W/M2.

Arthur:

have you ever touched your hand to a metal object sitting in the sun, or walked barefoot on a sandy beach on a hot day?

When M talks about discontinuity at the surface, it is the average global temperature, not a transitory temperature of surfaces of varying emmissivity. The standard theory predicts a considerable discontinuity at the surface in the global average temperature, which does not occur. Hence, M's theory is more accurate in that (and other )respects.

by a ratio that can be arbitrarily large.

I still suspect you are missing the point. The greenhouse factor G being looked at G is a ratio OLR/Su or Tearth/Tblackbody if you like. The Tblackbody is a product of certain flux level, heat or radiation. The Tearth or Tgreenhouse is a result of that same flux level entering into a bandpass diode-like enclosure . The flux can't be arbitrary, but must be the same as the background of the apparatus.

I'm fascinated byArthur's stratospheric cooling explanation:
"The radiative effects of the added water vapor will be small --- they also would likely be negative (leading to cooling), because the entire inside of your container is at a pretty uniform higher temperature. This is what happens with GHG’s in the stratosphere: they radiate at a higher level when at a higher concentration, resulting in a *cooling* of the stratosphere."

I assumed that stratosphere cooling by AGW is mainly due to more heat energy being trapped farther down: ie energy balance. Then again, on reading the IPCC scientific basis report they seem to conclude that it's ozone depletion causing most, if not all of the cooling. Does that put Arthur's mechanism in a poor 3rd place among the best guess mechanisms?

In designing the experiment one must be aware that under ideal conditions, a temperature change of about 0.017C is the most that could be expected under the best of circumstances as a result of changes in absorption reemission in atmosphere inside the vessel that is used.


Check out my calculation in the Home Science experiment post no 70.
http://landshape.org/enm/science-experiment-at-...

Alex Harvey // Nov 18, 2008 at 1:07 am

"Eric # 32:

If a piece of research is cited so often, it must be an authoritative and accepted piece of work. In the field of science that counts for a lot.

Once again, we find the only reason people can find to believe something is that everyone else believes it. I like this quote."

It is cited because the experts in the field find it useful. That is a good recommendation in my book, if I am unable to find the time to read it and evaluate it for myself.

Of course one doesn't take advice on things from people who are ignorant of a subject, no matter how many of them repeat the same thing.

A cited reference is not the same as an old wives tale.

Arthur, you say:

"How would you get precise numbers on the average convective heat flux? Looking at a climate model’s convection would be a good place to start - in fact, I believe that’s what the Kiehl-Trenberth diagram is based on. Feel free to suggest a better way to measure or estimate it!"

I don't know how to estimate the total effect of convection, but it's got to be more than 24 wm-2. The temperature difference between the outside and inside of a greenhouse proves that to me, as I said before. All that extra heat is removed by convection. I think that Miskolczi says that virtually ALL energy from the surface is transferred to the atmosphere by non-radiative means (convection, latent heat). I think that is right. As any engineer knows, thermal radiation is a very poor way to get rid of heat. And Mother Nature is at least as smart as the engineers. :)

Anyway, what brings this up at all? Is this one of Miscolczi’s bugaboos?


Yes. Please read M's papers and Zagoni's explanations. Then we could discuss. Easy to google.

The microlayer of water next to the air is probably in thermal equilibrium with the air. Otherwise, the absolute humidity of the air over moist areas would not be as close to saturation as it is (average of about 75% saturation at 20 C).

More on "discontinuity in temperatures at the surface" - in general, the temperature of the air (a few feet) above water can be quite different from the water temperature: if you don't believe this, I challenge you to a swim in the Atlantic on a warm day in March! In late fall, or on summer nights, the water temperature can be quite a bit higher than that of the nearby air. Having continuous temperatures along some curve means maintaining local thermodynamic equilibrium along it, but if the curve crosses a material boundary, there is no good reason such equilibrium should be maintained: the constituents on one side of the boundary do not easily cross to the other, the boundary itself is a material discontinuity. Temperature may be the same on either side if the two sides have had enough time to equilibrate, but it's a much slower process than actual mixture of materials within one side or the other. If it's not instantaneously continuous, there's certainly no reason it should be continuous on average either.

Anyway, what brings this up at all? Is this one of Miscolczi's bugaboos?

Jae writes:

Again, the surface of the planet during the day would be exactly like a closed greenhouse if it were not for convection.

- yes, but think of the other consequences. Imagine our air was replaced by a medium with very high viscosity so it could not move about easily, and a density independent of temperature to prevent convective instabilities. Without convection hot "air" would stay in the tropics. The poles would be considerably colder, with no warm lower-latitude air coming in during the summer, and heading towards absolute zero during their long winter nights - the convective greenhouse does not help if the sun is not shining. So mid-latitude day-time convective flow is not the typical situation and the average convective greenhouse (removing net convective flow) does not actually warm the surface very much on average.

How would you get precise numbers on the average convective heat flux? Looking at a climate model's convection would be a good place to start - in fact, I believe that's what the Kiehl-Trenberth diagram is based on. Feel free to suggest a better way to measure or estimate it!

Jae also asks:

What about the disconuity at the surface? It doesn’t happen in real life

- actually, I have no idea what you're talking about: the Kiehl-Trenberth diagram doesn't claim, mention, or as far as I know depend on any discontinuity (in temperature?) at the surface. On the other hand, a (near) discontinuity in temperatures at the surface isn't unheard of - have you ever touched your hand to a metal object sitting in the sun, or walked barefoot on a sandy beach on a hot day?

And yes, I am a "true-believer" in physics :-)

David Stockwell writes:

I think you misunderstand.

You can’t discharge into a cold vacuum. It has to be at the same temperature as the black body temperature of in incident radiation.

There is no incident radiation in my proposed experiment - the heating comes from an electrical element on the bottom surface, which replaces the heating of Earth's surface by incoming solar energy. The purpose of the cold vacuum is to try to closely mimic the situation for Earth as a whole, where there is essentially no incoming thermal radiation from surrounding space to our planet. You could do my proposed experiment at a variety of enclosure temperatures to see what effect that has - obviously, warmer enclosures will add some incoming thermal radiation to the system, resulting in slightly warmer temperatures. But even with a near-absolute-zero enclosure, infrared absorption in the system will keep the bottom surface warmer than the temperature you get from Stefan-Boltzmann, by a ratio that can be arbitrarily large.

cohenite writes:

another thing he http://landshape.org/enm/model-of-global-warmin... addressed is the lack of a THS or Stratosphere cooling independent of volcanic residual effects.

I am not familiar with the acronym "THS". Pinatubo warmed the stratosphere, but overall it's been cooling - you seem to have some argument here with which I'm completely unfamiliar.

"ZnSe won’t work - it’s transparent to IR but not sunlight. But David is building a solar furnace. He added glass and it got warmer. Bubble-wrap would make it warmer again. He’s aiming, apparently, to show a max of about 60C, which insulation gets you towards, and more insulationwould exceed it. But what type of wall is wanted? Should it be transparent to all radiation? If so, how is it a test of anything except the ability to block convection?"

No, I think more insulation would just raise the boundary temperature, and the 3/2 relationship would still hold.

Geoff #59
LTE is a property of gas in general at a particular temperature and pressure - related to mean free path of molecules. It's not particularly associated with IR or GHG or other individual gas components, trace or otherwise. And its effect, as above, is to ensure that kinetic energy, for example, is evened out locally faster than any process you're likely to try to measure. The practical effect here is that you don't need to worry about GHG molecules being individually heated. They absorb IR as individual molecules, but the heat immediately becomes a property of the gas mixture locally.

#56 Nick

Thank you, i appreciate what you say. But my concern is not to assume LTE at some given density, but to work out the actual heat taken in by dispersed GHG molecules before LTE can be achieved. From lab experiments with GHG at high concentrations, we can work out how much heat and light is found, but it's a rather more subtle exercise when the candidate gas is a few ppb in the atmosphere. My mind cannot make the leap from the GHG being a major component in an experiment, to it being a trace component. Why, other gases like nitrogen might partake of the incoming energy before the trace GHG even sees it. LTE is still established, but without any greenhouse effect in this scenario. So how much GHG in an atmosphere does one have to have to measure its temperature change in rection to energy input? Is it valid to extrapolate from high concentrations? What is the lowest concentration of methane, for example, whose presence can unequivocally account for a quantitative effect when light is passed through it?

Nick #57

"ZnSe won’t work - it’s transparent to IR but not sunlight"

That's the general idea so it won't be a solar furnace. It only excludes blue green light from the sun so it shouldn't be a problem for some solar heat to get in.

Jan #54
ZnSe won't work - it's transparent to IR but not sunlight. But David is building a solar furnace. He added glass and it got warmer. Bubble-wrap would make it warmer again. He's aiming, apparently, to show a max of about 60C, which insulation gets you towards, and more insulationwould exceed it. But what type of wall is wanted? Should it be transparent to all radiation? If so, how is it a test of anything except the ability to block convection?

#55 Geoff
The concept which is relevant here, often misunderstood, is local thermodynamic equilibrium. This basically means that a temperature can be measured. It is often quoted as a requirement for Kirchhoff's Law (the real one). It means that gas collisions are so frequent that processes involving them proceed faster than anything else you can measure. This includes the averaging of collision impulses that constitute pressure, or of kinetic energy exchanges that constitute temperature. LTE applies in the atmosphere except for the most rarefied levels.

My PC has been off-line for 5 weeks, so you can all rejoice at the unexpected break. But I'm back.

Philosophically, a thought experiment has troubled me for some time. It concerns the difference between heat and temperature in a gas, particularly in a rarified atmosphere.

The gas atoms/molecules have an energy which is related to heat. The faster they move, as a group, the more heat there is. But, something has to detect this heat and we use devices like mercury thermometers. Problem. If we have sparse gas molecules, they have a relatively large mass of mercury to interact with. Although they might be full of energy and moving fast and hot, there simply might not be a large enough number of them to intersect the mercury and change it significantly.

For related reasons, way out in space, the temperature might be the 3K micromave temp, but if you place an object like a satellite there, it can get hot from radiation. Radiation is waves not particles, but it simply complicates my thought experiment, which is to devise a heat measurement device that produces an answer correct in physics. I suspect that some of the above arguments touch on this thought experiment, especially when one is dealing with trace GHG and trying to determine how their real temperature is measured before being passed on to surroundings.

Nick #50

It's Arthur that want's him to build a solar oven in order to prove that things can only get hotter.

This is what the walls need to made of

Eric
"IR Radiation has to pass through many KM of atmosphere for significatnt fraction to be asbosbed."

Steady state fog above a swamp. (cloud chamber)
How to design a thin layer of fog into the experiment ?

Zagoni states that high altitude clouds insulate, equivalent to closing the 10 micron window. So if we get a semi-transpatent steady state fog. Can we expect Su=3OLR/2 ? Measure with a couple of photocells, up and down looking.

Nick:

"You are supposed to be testing a formula based on IR transmission. Is the wall supposed to be IR transparent? And is it? Why would the thermal conductivity matter?"

No, the wall is not IR transparent for glass, but it doesn't matter. I think the Wood Experiment back in the 20's or 30's showed that this doesn't matter wrt the greenhouse effect. (He compared a NaCl greenhouse, which is transparent to IR to one with glass. Same temperatures inside, as long as the sun's NIR was blocked by glass. Long ago, I did experiments with polyethylene greenhouses, which are also quite transparent to IR; same results as David got. David's experiment makes sense to me. The outside of the greenhouse is at ambient temperature (or very close). That simulates the lower boundary condition. Move the greenhouse higher and higher in the atmosphere and the same thing happens. I think?

It needs to meet the ambient boundary value. Perfect insulation would not do that, or it would take a long time to equilibrate. I am working on a post about this, so more later about insulation layers. Sorry I can't answer all your previous tricky questions right away. Just too many right now.

David #30
"Should not be insulated"? But why not? Or to put it another way, what kind of boundary are you trying to achieve? You started with plastic, which has not only a membrane, but on each side a boundary layer of near-stationary air, which is a good insulator. You then went from plastic to glass, which is a bigger barrier to conduction. Why would adding more insulation alter the principle you are testing? I was going to suggest adding a layer of bubblewrap, which would probably increase the temperature substantially.

You are supposed to be testing a formula based on IR transmission. Is the wall supposed to be IR transparent? And is it? Why would the thermal conductivity matter?

Yes, Arthur is a confident chap; and another thing he hasn't addressed is the lack of a THS or Stratosphere cooling independent of volcanic residual effects.

I think I understand, David. Brilliant! Boundary conditions apply.

Arthur: Thanks for your lengthy description of your ideal experiment. Which illustrates why I think people need to be patient in dialogue while they work out what each other is saying. I think you misunderstand.

You can't discharge into a cold vacuum. It has to be at the same temperature as the black body temperature of in incident radiation. What you perhaps could do is sit the whole experiment on an insulating sheet, and heat the inside dark body with the same energy level as what it would take to bring it to the ambient level. Alternatively, if you wanted to sit it at 2K, then you could only supply the energy equivalent of 2K to it. The temperature then could at most be 4K, unless you live in RealClimate world, where it could be 4K, 6K, 8K, 10K whatever you like. In practise I think its going to be at 3K for reasons mentioned.

<abbr>David Stockwells last blog post..Model of Global Warming</abbr>

Arthur:

"Remember this is the *net* *average* heat flow from the surface to the atmosphere caused by convection. During a hot clear summer day, at low latitudes, the heat flow is quite high. At night, and as the atmosphere circulates between low and high latitudes, the heat flow drops or even goes negative (the atmosphere warming the surface). The net is much less than the peak flow rates. The latent heat flow is also quite variable, but I don’t think it goes negative anywhere (evaporating water always cools the surface and warms the atmosphere where it condenses)."

Baloney, methinks. Again, the surface of the planet during the day would be exactly like a closed greenhouse if it were not for convection. You can average that effect anyway you want to, and you can't get a measly 24 w/m^2 for convection. As Miskolczi demonstrates, the transfer of energy from the surface occurs by non-radiative means. Radiation is small potatoes, when convection occurs (think, again, about why you have a fan in your computer, instead of a simple heat sink). And I again pose the question: What about the disconuity at the surface? It doesn't happen in real life, only in radiation cartoons (which is why the term "cartoon" fits so well). None of you true-believers* have addressed that very important question, to my knowledge.

*I label you thus, because you are just too damn certain of yourself. Like you know it all. You end up looking like a preacher! If you were being a straightforward scientist, you would find at least SOMETHING that is not absolutely certain. Hell, even IPPC didn't come out with 100 % certainty.

David, you noted

I think the outside of the vessel must not be insulated

in response to my comment that, properly insulated, you should reach 90 C. Of course the outside of the vessel is in contact with the ambient atmosphere, that defines "outside" - the question is the degree of insulation between outside and inside - i.e. a well-sealed container (no convective heat flow), with thick double-paned glass (to reduce conductive heat flow) would be better controlled. Just like a well-insulated house, except with transparent walls and ceiling to allow radiative energy flows. That should be the ideal set-up for your experiment (to the extent you are actually testing any hypothesis here), and under those conditions you should be able to reach quite a bit higher temperatures, pretty much independent of the external "ambient" temperature.

Kuhnkat asks about the "lowered" temp you observed - well, you didn't exactly add greenhouse gases, you added liquid water. That has to evaporate (thanks to the low humidity), which consumes energy, lowering temperatures. Not exactly unexpected. The radiative effects of the added water vapor will be small as Nick has mentioned - but in fact they also would likely be negative (leading to cooling), because the entire inside of your container is at a pretty uniform higher temperature. This is what happens with GHG's in the stratosphere: they radiate at a higher level when at a higher concentration, resulting in a *cooling* of the stratosphere. That cooling is at least partially responsible for the imbalance between incoming and outgoing radiative energy that results in warming of the planet beneath. There's certainly no reason to believe, based on the standard understanding of the atmospheric greenhouse effect, that additional water vapor in such a container will leave it warmer rather than cooler. A lowered temperature is quite unsurprising for both of these reasons, though I expect the evaporative latent heat effect is much more significant.

Jae asks, quite reasonably:

why do the radiation cartoons suggest that convection accounts for only 24 W/m^2?

Remember this is the *net* *average* heat flow from the surface to the atmosphere caused by convection. During a hot clear summer day, at low latitudes, the heat flow is quite high. At night, and as the atmosphere circulates between low and high latitudes, the heat flow drops or even goes negative (the atmosphere warming the surface). The net is much less than the peak flow rates. The latent heat flow is also quite variable, but I don't think it goes negative anywhere (evaporating water always cools the surface and warms the atmosphere where it condenses).

Once again, what David's experiment demonstrates is the traditional physical greenhouse effect. If we actually wanted to test an analog of the atmospheric greenhouse effect on a laboratory scale you would probably need to meet the following conditions:

* A system capable of holding a large temperature differential from top to bottom (i.e. not a gas or liquid, they can't hold large temperature differentials on a laboratory scale thanks to convection - some sort of solid material with low thermal conductivity perhaps)
* Several versions of the system with differing bulk absorption levels in the thermal spectral region, but otherwise with identical heat capacity, thermal conductivity, etc.
* A steady source of heat on the bottom, perhaps an electrical element (the fact that incoming solar energy is radiative is irrelevant to the basic physics of the atmospheric greenhouse effect - as long as the surface is heated some way or other, that's all that matters).
* A bottom surface that is close to a black body (perfect absorber and radiator) at thermal wavelengths.
* All surfaces except the heated side of the bottom free to radiate into a cold vacuum (surround the laboratory system by a cooled enclosure).

Then the relevant hypotheses are (a) the temperature of the lower, heated, surface will be higher the higher the bulk infrared absorption level is, and (b) it will rise with no particular limit on its relation to the ambient cold enclosure as that absorption is increased.

Eric # 32:

If a piece of research is cited so often, it must be an authoritative and accepted piece of work. In the field of science that counts for a lot.

Once again, we find the only reason people can find to believe something is that everyone else believes it. I like this quote.

David: does your "greenhouse" have a black floor?

Eric:

"IR Radiation has to pass through many KM of atmosphere for significatnt
fraction to be asbosbed."

That just doesn't make sense. The air at the surface in the real world is not just heated by contacting the surface (if the air was over cold water, it would never heat). It is heated primarily by thermalization reactions, wherein the IR-excited GHG molecules collide with the N2 and O2 molecules (and they with each other, and so on). And this could not be a major mechanism, if the path length were "many kilometers." In your world, you could not have LTE!

"IR Radiation has to pass through many KM of atmosphere for significant fraction to be absorbed."

CO2 exhausts its absorption at around 650/cm; the KT model shows this, as does HARTCODE and the Cabauw verifications.

I forgot to include thermalization by contact with the "floor" and other materials in the greenhouse.

It would be interesting to fill the greenhouse with pure oxygen and see how fast it warmed up. In that case, all the thermalization would have to occur by contact with the surfaces. There would be no absorption of IR by the "air." I'll bet that would be much less effective in heating the air, but maybe not?

IR Radiation has to pass through many KM of atmosphere for significatnt
fraction to be asbosbed. The upper atmosphere has no walls with which to collide, so radiatin is the princple way it gains energy. Collisions with the walls are more frequent for gas molecules in the jar. All the molecules participate, not just the GHG's. I am quite sure that the absorption of IR radiation by GJG's is not significant in determinint the temperature of the gas in the glass.

It is the job of texperimental scientist to support the conclusions of his experiment by showing that the mechanims I have mentioned are negligible.
Why not direct your questions at him?

Eric, 37
"They molecules get their energy from the walls of the container by collisions."

Are you sure? I don't think you are viewing this correctly. The glass is transparent to the SW radiation. As I understand the workings of a greenhouse, the SW is absorbed by the "floor" and contents of the container, reemitted as IR, absorbed by ghgs, and is then transferred to the rest of the air by THERMALIZATION . SOME IR energy is also absorbed by the glass and thermalizes the air inside. And some IR energy "leaks" by conduction through the glass and provides energy to the outside air by (this is why the container's temperature doesn't quite get to the black line, and it is a minor deal). Have I got this wrong?

31 kuhnkat // Nov 17, 2008 at 10:14 pm

"Arthur Smith and Eric,

You apparently do not have a problem with the result of lowered temp with the ADDITION of GHG??"

I don't know what you are talking about.
I have said that the results of the experiment have nothing to do with absorption and emission properties of GHG's.
The GHG's in the glass, as Nick has pointed out, absorb a miniscule fraction of the incident radiation because the total number of absorbers is so small. It takes Km of air to absorb a sizeable amount of radiation.
They molecules get their energy from the walls of the container by collisions.

David #30

I think the outside of the vessel must not be insulated so it can approach ambient.

A point certain folks around here seem to be missing, and that ambient was constant throughout the experiment and in fact it was a controlled trial.

kuhnkat: The response to that will be that "the optical path is too long for the GHGs in the little greenhouse to have an effect."

But the optical path is certainly long enough in the tropics. However, temperatures there never go over about 32-33 C. Why not, if additional GHGs cause more heating? Surely, we should see some 40 C readings in the heat of the day, jsut like in dry areas, but we don't. And where is all the "positive water vapor feedback" in the tropics. Heck, using the IPCC concept, it should be 50-60 C during the day in the tropics, no? It seems to me that is that there is an over-supply of GHGs, and all the water feedback is negative, effectively creating a thermostat. I'll bet that 32-33 C is the maximum attainable average temperature for the Earth, and it would be a very, very cloudy place, indeed.

Arthur:

"Earth’s surface doesn’t achieve those temperatures because convection quickly wicks the energy away from the surface to warm the atmosphere (and at the ocean surface convection works similarly in a downward direction), and the associated heat capacity is sufficient to maintain a relatively stable atmospheric temperature between day and night."

Right on! Then why do the radiation cartoons suggest that convection accounts for only 24 W/m^2? BTW, you are getting very close to saying that thermal storage has something to do with the "greenhouse effect."

"Do you claim that the scientists and professors don’t know what they are talking about? Do you really have enough knowledge to make that judgement?"

Come on Eric, gimme a break, already. There are serious disagreements among serious "scientists and professors" on these matters. So, yes, I think they generally know what they are talking about, but they cannot all be right. I am also a scientist and I was trained in the (maybe old-school?) tradition of not accepting everything that is written, not even if it is in a peer-reviewed journal.

I am very well aware of all these "radiation cartoons." Miskolczi, for one, doesn't agree with them. Especially with regard to the surface discontinuity (a subject which you seem to be avoiding, altogether). What I'm trying to discover is who's right.

Jae said,

Eric:

LOL, that TAMU article is hardly “deep science.” Looks like it was written for a high school primer on the subject. Same-ol, same-0l stuff that’s everywhere. Why did you link it?

I linked to it, because it has an energy balance diagram for the earth showing the values of upward radiation and solar radiation absorbed by the earths surface. You asked where those numbers in the RealClimate article came from. I also linked the original source of those numbers which is a scientific journal article.

The diagram has appeared in many links which you can find on this subject on the internet. If a piece of research is cited so often, it must be an authoritative and accepted piece of work. In the field of science that counts for a lot.
In the denier blogosphere, it apparently doesn't mean anything.

Do you claim that the scientists and professors don't know what they are talking about? Do you really have enough knowledge to make that judgement?

Arthur Smith and Eric,

You apparently do not have a problem with the result of lowered temp with the ADDITION of GHG??

Suitably insulated, your experiment could easily achieve temperatures of 90 C at least, well over your 1.5 limit even with normal ambient temperatures - and that 90 C is accessible even when the outside temperature is freezing too.

You have a clear position, except for the "suitably insulated" part. I think the outside of the vessel must not be insulated so it can approach ambient.

<abbr>David Stockwells last blog post..Model of Global Warming</abbr>

Black body temperature for normal (clear-sky) solar intensity of at least 1000 W/m^2 is found on the surface of the Moon in the middle of the lunar day. Earth's surface doesn't achieve those temperatures because convection quickly wicks the energy away from the surface to warm the atmosphere (and at the ocean surface convection works similarly in a downward direction), and the associated heat capacity is sufficient to maintain a relatively stable atmospheric temperature between day and night. A physical greenhouse (like your experiment, or like the inside of a parked car) gets warm under the sun because it prevents that wicking-away process, confining almost all the absorbed heat locally. As Nick has been explaining to you. Suitably insulated, your experiment could easily achieve temperatures of 90 C at least, well over your 1.5 limit even with normal ambient temperatures - and that 90 C is accessible even when the outside temperature is freezing too.

it could simply be an accident.

It could be, thats what I want to find out. So far, in the configurations I have used, the expected maximum has almost been achieved, and increasing GHG has reduced the temperature. No doubt if the max is exceeded in a reasonable configuration without increasing isolation (mirrors etc) you would agree it is falsified. If its not, then would you concede?

Hi Arthur, You can't use the ratio of temperature of x/2 in space, you would have to use OLR. In that case, you would have a situation identical to the earth, and the result should be 3/2, as the earth demonstrably obtains. Being a home experiment (at home) I rely on the ambient as an approximation of the black body temperature for a given solar intensity. Thats why I think it is approximately valid to run it for a clear sky in the middle of the day, but not when its cloudy, sunrise, sunset etc. Cheers

David - you are calculating a ratio that depends on the temperature achieved inside your greenhouse to "ambient" outside temperature. There are much better greenhouses than the one you have devised - thick double- or triple-paned glass for instance to let the light in and avoid conductive heat loss. Put your little experiment (with sufficient insulation) out in space, and you can easily achieve hundreds of degrees C, with an "ambient" temperature of 2 K or so, for a T^4 ratio in the millions. Run your experiment in the arctic or antarctic and see how it does. Or just wait for freezing winter-time temperatures: real greenhouses exist with no internal heat source that maintain 30 C inside with outside temperatures of -20C, which gives you a T^4 ratio over 2.

In other words, this experiment may tell you something about how physical greenhouses behave, but it has nothing to do with the way so-called "greenhouse" gases work, and your greenhouse ratios are meaningless in relation to the actual atmospheric GHE.

"“We have to be careful here. One problem in the debate is people (engineers for example) who understand just enough math to get into trouble.”

Not only engineers, but chemists. I may be in that camp, but I am learning, and that is my goal :)

Eric:

LOL, that TAMU article is hardly "deep science." Looks like it was written for a high school primer on the subject. Same-ol, same-0l stuff that's everywhere. Why did you link it?

"5. If the maximum greenhouse effect is 1.5, then RealClimate and the conventional understanding of greenhouse effect is wrong."

From the expert -- Spencer Weart;
"We have to be careful here. One problem in the debate is people (engineers for example) who understand just enough math to get into trouble."

Are engineers ignoring this silly talk ?
After all, the Earth needs terraforming

"My link, which you refer to as a paper, is an online text book in Oceanography for college students, by a research professor from Texas A & M.
The research you are quarreling with can be found here:"

I was referring to K&T, which doesn't appear to me to be based on any better evidence than Miskcolczi's papers. Still waiting to hear about the surface discontinuity.

BTW, p.200 in KT starts out with this sentence: "We must rely on model calculations to determine the surface radiative fluxes." Hmmm, that is not empirical evidence. Miskolczi does better.

Proofs of errors in the Kiehl-Trenberth distribution
See Zagony: http://hps.elte.hu/zagoni/Proofs_of_the_Miskolc...

My link, which you refer to as a paper, is an online text book in Oceanography for college students, by a research professor from Texas A & M.
The research you are quarreling with can be found here:

http://www.atmo.arizona.edu/students/courselink...

I wouldn't have had a chance at the cheap shot, if the paper would have stood scrutiny by the atmospheric physics community. I admit that I am not a mind reader, but the mistakes found in the Miskolczi paper, are consistent with an expectation that its publication in a main stream journal would not be possible. A paper of such importance, if it were valid, would get more favorable attention in the climate science community, and citation than this one has.

If you have some specific flaws to point out in the research by Kiel and Trenberth, it would be of interest to know what it is, and why you find it unconvincing.

Eric: I've read that paper. It is certainly no more "convicning" than Miskolczi's. Care to explain the discontinuity at the surface?

BTW,
"The paper itself was published in an obscure Hungarian journal because it would not pass peer review in a respectable international journal."

That is a cheap shot, Eric, and I don't need to tell you which logical error is involved with the statement. And Steve McIntyre is showing over and over that "peer review in international journals" doesn't mean much in the "climate science" world, especially in cases where close buddies and former co-authors are the reviewers. Climate science has a black eye, IMHO.

Jae,
If complex science scares you , maybe you should stop reading about it.
Complexity is a fact of life.

The measurements are from a classic paper published by Kiehl and Trenberth (1996).
See the diagram in the following link for a description of the earth's energy balance.

http://oceanworld.tamu.edu/resources/oceanograp...

The real model is too complex to describe in detail.

Now, that is really scary. How can you validate such a model?

"The value of lambda, as I pointed out is not derived from the equation, but taken from real measurements of upward IR radiation, which average 390W/M2, versus 240 W/M2 for the actual incoming solar radiation not directly reflected into space."

Where can I get those measurements?

Jae said,

Eric: Is RC’s model “trash,” too?

It is not a real model. It is a conceptual framework to help non scientists understand the gist of what is done in a real computer calculation. It fills a need to transmit to lay people, such as you and I, what the more complex equations and computer calculations are doing. The real model is too complex to describe in detail.

The value of lambda, as I pointed out is not derived from the equation, but taken from real measurements of upward IR radiation, which average 390W/M2, versus 240 W/M2 for the actual incoming solar radiation not directly reflected into space.

Jae,
Firstly, upper limits that are derived from equations that don't apply cannot be relied on to be correct. If they are consistent with data, it could simply be an accident.
Second, as I have already mentioned, the empirical data shows a ratio of upward radiation from the surface to incoming solar radiation of 1.62, which is larger than the supposed upper limit of 1.5 which is claimed as the upper limit according to Mizkolczi. This upward radiation is on top of the other means by which heat is removed from the surface to the atmosphere, transpiration and convection.

It would seem that a flawed derivation, and contradiction by experiment should doom this paper to oblivion.

The apparent lack of warming of the upper troposphere in the tropics was a result of data analysis problems which have been corrected, by recent papers.
With these corrections it has been shown that the upper troposphere is warmer than the surface, and has been warming.

The supposed conflict was with model elements unrelated to the absorption and re-reradiation by GHG's, but rather with the adiabitic approximation used to calculate the temperature of moist air which rises by convection.
This physical principle is alleged to be used by all climate models.

Eric:

"The validity of the theory of of Ferenc Miskolczi seems in doubt to people with a knowledge of physics who have read it carefully. People over at the Eli Rabbet blog have pointed out that Miskolczi’s invocation of the virial theorem with regard to the earth’s atmosphere is invalid, and his interpretation of the concept of local thermal equilibrium, and the misuse of Kirchoff equations."

The problem with all their criticisms about the Kirchoff Law and the Viral Theorem is that the empirical data seem to support M's concepts, regardless of whether M might be using the wrong terminology. The empirical data does not seem to support any alternative theories, especially the surface discontinuity nonsense. And no apparent warming of the troposphere at 10 K in the tropics, as predicted by all models.

Eric: Is RC's model "trash," too?

The characterization of the RealClimate simple Greenhouse model is not accurate. It is meant as an conceptual explanation of a much more complicated calculation that requires computers, so that people can understand the concepts involved and get a rough idea of the physical principles that operate, while putting up some reasonable numbers.
For example, the real atmosphere has a complicated dependence of temperature versus height, while they use a single value of temperature in their calculation. A more complex simplified model is given in the July issue of the Physics and Society Newsletter at the AIP web site.

The maximum possible greenhouse effect parameter, which reflects the ratio of the upward radiation from the ground, to the incoming solar radiation using this simplified model is 2. The actual value, which was derived from actual experimental data on upward radiation from the ground is given as
1.62 if you carry out the calculation using the value obtained for lambda.
This is obviously less than the theoretical limit, but clearly greater than 1 and is clearly greater than the 1.5 that you claim is the alternative theory's upper limit.

So it is the real data on upward radiation that is providing the value of the greenhouse parameter, not the simplified theory which illustrates how it works. The simplified theory is not meant to calculate the value of the greenhouse parameter itself, and cannot possibly do so.

The validity of the theory of of Ferenc Miskolczi seems in doubt to people with a knowledge of physics who have read it carefully. People over at the Eli Rabbet blog have pointed out that Miskolczi's invocation of the virial theorem with regard to the earth's atmosphere is invalid, and his interpretation of the concept of local thermal equilibrium, and the misuse of Kirchoff equations.

The paper itself was published in an obscure Hungarian journal because it would not pass peer review in a respectable international journal.

As has been pointed out, the simple experiment with the air and the bottle is trash, unless it is shown that the variation in radiation from the sun, and the IR and optical absorption of the container as well as the convection have been taken into account.

I thought the definitive model description for AGW was by Spencer Weart;

http://www.realclimate.org/index.php/archives/2...

This is the classical layered atmosphere with vertical CO2 barriers trapping the ascending IR. I don't get it. Everyone agrees that CO2 does its absorbing at around 650cms as the Cabauw measurements confirmed; at this level SU effectively =ED, but it is the equation ED=SU [1-TA] which is pertinent; this is consistent with Stefan-Boltzman and the Pielke Snr et al paper: "Unresolved issues with the assessment of multidecadal global land surface temperature trends." Basically at each ED=SU[1-TA] point there is a LTE; a Local Thermodynamic Equilibrium is defined as the distance an air molecule travels before encountering a temperature change; this is the mean free path of the molecule; with the GH effect at this low level there can be no discontinuity between the surface and the LTE above; the GH exchange is balanced and the CO2 molecules have been completely thermalised within the LTE air parcel; Miskolczi assumes at (c) on p3, that the atmosphere is in LTE but it is regionalised so that, as he says on p12, "At the top of the atmosphere the net IR radiative flux is equal to the global average outgoing long wave radiation." This is entirely consistent with Pielke Snr and Stefan Boltzman and requires no anthromorphised gaia-like planet which knows what IR should go where to achieve the Kirchhoff equilibrium. What happens at each LTE has been described by Chilingar and to a lessor extent, Douglass and Christy; the LTE is convectively lifted to the CEL, which at 7-8km, is far below the stratosphere outward emission point (OLR) demanded by the Weartian model. At the CEL the LTE parcel is no longer temperature distinguished from the surrounding air and its CO2 molecules can therefore emit outside the no longer thermalised LTE; and here is the issue; this air has lost energy rising; the isotropic emissions, ED and EU are equal, but the classical model says the CEL ED adds to the CO2 absorbing level ED and therefore adds energy to the surface; but it can't do this for number of reasons; the surface LTE will maintain itself because this is where the GH effect dominates; if there is more CEL ED then there will be more SU EU because the CO2 surface layer will cause it; no extra SU EU will be absorbed by the surface CO2 because that surface CO2 has been thermalised and saturated; any extra CEL ED will become SU EU passing through the saturated window. Alternatively, the Specific Humidity at the surface increases cooling of the effect of extra CO2 at that level. This appears to be happening. Is there anything happening which is consistent with the Weartian model?

David #9
No, they don't need to be separated by vacuum - just by IR transparent gas. The model just gathers the GHG in bands - everything else can remain in place. The mode of heat transfer is IR only between layers, then within, conduction of the heat intercepted by layers to keep the temperature on both sides the same (that's why the layers are assumed thin, so conduction is perfect).

The greenhouse theory actually just applies to any heat source at the surface - incident sunlight has the same effect as volcanoes or whatever. Something warms the surface, and some fraction G of the resulting IR gets through. On venus, the only complication is that the incident sunlight warms the atmosphere directly, but that doesn't explain the massive GE.

Nick: I think the layers have to be separated by a vacumn to be proper 'steel greenhouse' layers with a unit G factor. That simply is not the case. Venus is another issue, in that it is fully opaque to short wave. It is more truely semi-infinite. That is different from a setup transparent to short wave and opaque to IR, where the sun shines on the surface. Venus is also possibly emanating significant heat from the surface. It has to be solved for different conditions.

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#7 David
I'm quite comfortable with abstractions. But before taking RC's toy example too far you should note what they say about it:

While this is just a simple model that is not really very Earth-like (no convection, no clouds, only a single layer etc.), it does illustrate some relevant points which are just as qualitatively true for GCMs and the real world.

Now the single layer is a key issue. If you gather the GHG material into a single thin layer, as they say, you get a maximum G factor of 2. That doesn't mean that it will actually be 2; just that that is the max for a huge amount of GHG. But if you gather it into two layers the max is three. Into three layers, the max is 4. And so on.

Continuing abstractly, when you gather into more layers, each layer is more permeable than the single layer. So the increase in G is not as great as the increase in the max would be. But it can increase, and is not limited by 2. And as you increase the layers, you approach more closely the real continuum atmosphere.

That's just as well, because Venus is a hard test. the argument applies to it just as well as to Earth, but the G factor there is much greater than 2. So something is wrong with any argument that leads to 1.5 or 2.

#3 Nick, I guess if you argue that abstractions, including the RealClimate one, are of no relevance then it will difficult to discuss this with you. RealClimate's post says that this is their basic understanding of how the greenhouse effect works and we have known it for 100 years (dummy).

So how simple can you make a model that contains the basic greenhouse physics? Pretty simple actually.

The atmosphere is the greenhouse gas layer they refer to. There is no suggestion that CO2 and H2O concentration start, stop, then start again anywhere in the atmosphere as a 3 layer model would require. These things are mixed in the atmosphere. If the maximum greenhouse effect is 1.5 and not 2 as their model says, then they have been wrong for 100 years. If its 2 and not 1.5 then I am. It can't get much clearer.

David: Fascinating experiment. When I was a graduate student I worked two summers with the Forest Service in Colo. doing research on solar drying of lumber. We used large greenhouses, clad with PE. I remember seeing empty closed greenhouse temperatures as high as 160 F, but I don't remember what the ambient was. For the 3/2 relationship, it would have had to have been over 100 F. Very possible. Wish I still had all the data.

test

Nick #3

For Venus, OLR is only a bit higher than Earth, but Su is huge; a factor much higher than 2.

Don't you mean the OLR is a little higher on earth than for Venus? (about 20 K worth)

Venus fact sheet

Did you know that around about 50km altitude on Venus the temperature and pressure for Venus are similar to Earths ground level?

So pressure level : pressure level Venus us actually cooler than we expect it to be.

David, I don't believe there is any natural greenhouse factor that you can derive by elementary means. The realclimate example was just to give a simple analogy of how obstructing IR increases temperatures. It is equivalent to what you previously referred to as the steel greenhouse, where a gas that totally blocks IR is compressed to a single narrow thin layer. The factor of 2 is arbitrary; if you compress to two separate layers, you would get a factor of 3.

For Venus, OLR is only a bit higher than Earth, but Su is huge; a factor much higher than 2.

David, this comment relates to your previous post in this series, which doesn't seem to have a comments section. I couldn't understand this:

If you imagine an average atmospheric temperature E, radiation is propagating both up and down with an equal intensity of E/2. For balance of energy, Su=F+E/2 and F=OLR. But E is the atmosphere absorbed energy, equal to F. So Su=3OLR/2.

Is E a temperature or a flux (or an energy?)? Are you speaking of TOA (where maybe F=OLR)? Or is it an atmosphere of uniform temperature?

Jan, thanks again for the test/experiment and now the explanation. It should certainly raise some comments around the blogosphere.

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