Models of Greenhouse Effect

Here is a neat way to sum up a range of models of greenhouse effect using the overall energy balance equation of Miskolczi (M7). The energy balance equation represents two flux terms of equal magnitude, propagating into opposite directions, while using the same solar energy F as an energy source. The first term (Su-F) heats the atmosphere and the second term (Ed-Eu) maintains the surface energy balance.

F — Solar flux in
Su — Surface flux up
Eu — Atmospheric flux up
Ed — Atmospheric flux down

They can be represented as equations of linear algebra:

1.1 F = Su – F + Ed – Eu — overall energy balance equation
1.2 0 = F – Eu — energy balance at top of atmosphere

The following are different three constraints:

2.1 0 = Ed – Eu — the steel greenhouse, top of atmosphere constraint.
2.2 0 = Su – Ed — the Kirchhoff’s law, IR radiative equilibrium between surface and atmosphere
2.3 0 = Su – F — the third option, for completeness.

By substituting each of 2.1, 2.2 and 2.3 into 1.1 and 1.2 we get three different solutions for surface temperature with three decreasing levels of greenhouse effects.

3.1 Su=2F
3.2 Su=3F/2
3.3 Su=F

The three models of greenhouse effect are shown in the figure below, ordered by increasing surface temperature. Below the diagrams are representation of the modeled and equilibrium lapse rates, the increase in air temperature with altitude for each of the models.

Slide13.png

Here are a few points of interest that argue that the middle semi-transparent model is the correct model:

  1. In the left-hand model the model lapse rate increases faster than the equilibrium lapse rate — a quasi-stable atmospheric condition called an inversion. In the right-hand model the lapse rate increases more slowly than the equilibrium value — an atmospheric situation where large volumes of air rise through the profile. In each of these situations the equilibrium is eventually reestablished to the middle model, where the lapse rate is ‘just right’.
  2. Note that the models on the left and right side also have a discontinuity between the surface and the lower atmosphere. The center does not. Only the center model minimizes energy and maximizes entropy. Temperature discontinuities are not consistent with maximizing entropy.
  3. The three options could also represent zonal difference, from high to tropical latitudes.

In a previous post it was noted that the widely regarded semi-infinite model of greenhouse effect follows the ‘steel greenhouse’ solution. However, as noted above, this solution is one extreme that is unphysical due to the temperature discontinuity between the surface and the lower atmosphere.

Note that this simple model represents only the overall conservation of energy constraints on the system, and a number of other constraint and processes are in play (more discussed in the category Miskolczi above left). However, the central Kirchhoff law model is the only plausible solution with radiative balance throughout the whole atmosphere. However, this model suggests that all of the processes that contribute to the greenhouse effect are already contributing their maximum warming effect, as they cannot increase beyond the limits set by energy conservation. Miskolczi concludes that global warming must therefore be due to other mechanisms and not greenhouse gases.

95 Comments

  1. jae May 27, 2008 4:38 pm
  2. jae May 27, 2008 4:38 pm
  3. admin May 29, 2008 2:25 am

    Hi jae. No I had not until yesterday or so. Wish I had as it does give a genteler introduction.

    http://landshape.org/enm

  4. admin May 29, 2008 2:25 am

    Hi jae. No I had not until yesterday or so. Wish I had as it does give a genteler introduction.

    http://landshape.org/enm

  5. Ken Gregory June 1, 2008 7:15 pm

    There is a near infinite supply of greenhouse gases available to the atmosphere in the form of water vapor from the ocean to provide the greenhouse effect, but the relative humidity in the atmosphere is much less than one. Therefore, there must be some greenhouse equilibrium mechanism to control the relative humidity, and therefore the strength of the greenhouse effect. The precipitation systems controls the relative humidity.

    If some temporary disturbance adds a large amount of greenhouse gases into the atmosphere, temperatures will temporarily increase, as it did in 1998 due to the super El Nino. If one believes that a temperature rise will cause more water vapor, which will cause more temperature rise, and more water vapor yet again, one would expect temperatures to continue to rise after 1998. But the opposite happened, temperatures fell as the greenhouse equilibrium mechanism restored the balance. The extra greenhouse gases rained out to restore the equilibrium.

    This greenhouse equilibrium mechanism doesn’t care if the initial increase of greenhouse gases was water vapor or CO2. If somehow we suddenly released an amount of CO2 to the atmosphere equal in GHG effect of the 1998 El Nino water vapor , the temperature effect would be the same. Temperatures would increase by 0.6 Celsius, but would fall within a year to the original temperature, as the greenhouse equilibrium mechanism restores the greenhouse strength to the equilibrium value by raining out the excess greenhouse gases. Adding man-made CO2 to the atmosphere just rains out an equivalent amount of water vapor.

    The role of precipitation systems in controlling the greenhouse effect is described in Dr. Roy Spencer’s article Global Warming and Nature’s Thermostat here http://www.weatherquestions.com/Roy-Spencer-on-global-warming.htm, which is an extension of extension of Richard Lindzen’s “Infrared Iris” hypothesis.

    Dr. Spencer says we don’t know why the greenhouse effect is limited to its current value. That was before the Miskolczi paper, Greenhouse effect in semi-transparent planetary atmospheres. This paper describes the overall energy balance equations that limit the greenhouse effect to the current value.

    http://www.friendsofscience.org

  6. Ken Gregory June 1, 2008 7:15 pm

    There is a near infinite supply of greenhouse gases available to the atmosphere in the form of water vapor from the ocean to provide the greenhouse effect, but the relative humidity in the atmosphere is much less than one. Therefore, there must be some greenhouse equilibrium mechanism to control the relative humidity, and therefore the strength of the greenhouse effect. The precipitation systems controls the relative humidity.

    If some temporary disturbance adds a large amount of greenhouse gases into the atmosphere, temperatures will temporarily increase, as it did in 1998 due to the super El Nino. If one believes that a temperature rise will cause more water vapor, which will cause more temperature rise, and more water vapor yet again, one would expect temperatures to continue to rise after 1998. But the opposite happened, temperatures fell as the greenhouse equilibrium mechanism restored the balance. The extra greenhouse gases rained out to restore the equilibrium.

    This greenhouse equilibrium mechanism doesn’t care if the initial increase of greenhouse gases was water vapor or CO2. If somehow we suddenly released an amount of CO2 to the atmosphere equal in GHG effect of the 1998 El Nino water vapor , the temperature effect would be the same. Temperatures would increase by 0.6 Celsius, but would fall within a year to the original temperature, as the greenhouse equilibrium mechanism restores the greenhouse strength to the equilibrium value by raining out the excess greenhouse gases. Adding man-made CO2 to the atmosphere just rains out an equivalent amount of water vapor.

    The role of precipitation systems in controlling the greenhouse effect is described in Dr. Roy Spencer’s article Global Warming and Nature’s Thermostat here http://www.weatherquestions.com/Roy-Spencer-on-global-warming.htm, which is an extension of extension of Richard Lindzen’s “Infrared Iris” hypothesis.

    Dr. Spencer says we don’t know why the greenhouse effect is limited to its current value. That was before the Miskolczi paper, Greenhouse effect in semi-transparent planetary atmospheres. This paper describes the overall energy balance equations that limit the greenhouse effect to the current value.

    http://www.friendsofscience.org

  7. JM June 3, 2008 6:18 pm

    Maybe there’s something I’m not getting but something appears seriously wrong here.

    “3.1 Su=2F
    3.2 Su=3F/2
    3.3 Su=F”

    3.1 or 3.2 mean the surface has greater output flux than the input solar flux – clearly wrong.

    3.3 says the surface is a mirror (probably with zero atmospheric flux as well) – also clearly wrong.

    Are you sure you’re presenting this right?

  8. JM June 3, 2008 6:18 pm

    Maybe there’s something I’m not getting but something appears seriously wrong here.

    “3.1 Su=2F
    3.2 Su=3F/2
    3.3 Su=F”

    3.1 or 3.2 mean the surface has greater output flux than the input solar flux – clearly wrong.

    3.3 says the surface is a mirror (probably with zero atmospheric flux as well) – also clearly wrong.

    Are you sure you’re presenting this right?

  9. admin June 3, 2008 6:42 pm

    >3.1 or 3.2 mean the surface has greater output flux than the input solar flux – clearly wrong.

    Su>F is the greenhouse effect.

    >3.3 says the surface is a mirror (probably with zero atmospheric flux as well) – also clearly wrong.

    These are consequences of different constraints – neither right or wrong.

    http://landshape.org/enm

  10. admin June 3, 2008 6:42 pm

    >3.1 or 3.2 mean the surface has greater output flux than the input solar flux – clearly wrong.

    Su>F is the greenhouse effect.

    >3.3 says the surface is a mirror (probably with zero atmospheric flux as well) – also clearly wrong.

    These are consequences of different constraints – neither right or wrong.

    http://landshape.org/enm

  11. JM June 4, 2008 12:14 am

    “Su>F is the greenhouse effect.”

    So you’re saying that the upward flux from the surface of the earth is greater than 1380 W/m2 (the incident solar flux at the top of the atmosphere)?

    Where’s the extra coming from? (Double in the case of 3.1, 50% more in the case of 3.2)

    3.3 clearly doesn’t apply (the earth is not a mirror)

    Second issue. If 2.1, 2,2, 2.3 are *alternative* constraints, when is it permissible to disregard Kirchoffs *law*? It would seem to me the model should comply with it at all times.

    The presentation here just doesn’t make sense. I think you’ve got something wrong.

  12. JM June 4, 2008 12:14 am

    “Su>F is the greenhouse effect.”

    So you’re saying that the upward flux from the surface of the earth is greater than 1380 W/m2 (the incident solar flux at the top of the atmosphere)?

    Where’s the extra coming from? (Double in the case of 3.1, 50% more in the case of 3.2)

    3.3 clearly doesn’t apply (the earth is not a mirror)

    Second issue. If 2.1, 2,2, 2.3 are *alternative* constraints, when is it permissible to disregard Kirchoffs *law*? It would seem to me the model should comply with it at all times.

    The presentation here just doesn’t make sense. I think you’ve got something wrong.

  13. admin June 4, 2008 12:40 am

    No the surface averaged flux, taking into account the rotation of the Earth, but yes it is more than the average incoming. Its balanced by the atmosphere down flux. Thats the point of the greenhouse effect.

    As to Kirchhoff;s law, some disagree with its application to the atmosphere it seems. Check out the CA BB and discussions with pliny elsewhere on the Miskolczi topic.

    http://www.climateaudit.org/phpBB3/viewtopic.php?f=4&t;=161&st;=0&sk;=t&sd;=a&start;=110

    JM you are asking the right questions to improve understanding at least. Cheers

    http://landshape.org/enm

  14. admin June 4, 2008 12:40 am

    No the surface averaged flux, taking into account the rotation of the Earth, but yes it is more than the average incoming. Its balanced by the atmosphere down flux. Thats the point of the greenhouse effect.

    As to Kirchhoff;s law, some disagree with its application to the atmosphere it seems. Check out the CA BB and discussions with pliny elsewhere on the Miskolczi topic.

    http://www.climateaudit.org/phpBB3/viewtopic.php?f=4&t=161&st=0&sk=t&sd=a&start=110

    JM you are asking the right questions to improve understanding at least. Cheers

    http://landshape.org/enm

  15. JM June 4, 2008 9:10 am

    ” yes it is more than the average incoming. ”

    Where is it coming from then? I wasn’t aware that the earth generated its own electromagnetic radiation.

  16. JM June 4, 2008 9:10 am

    ” yes it is more than the average incoming. ”

    Where is it coming from then? I wasn’t aware that the earth generated its own electromagnetic radiation.

  17. Anonymous June 4, 2008 10:06 am
  18. davids June 4, 2008 10:06 am
  19. JM June 4, 2008 11:41 am

    David (at #8)

    I understand the greenhouse effect, I also understand thermodynamics and energy balance models.

    I asked you a simple question. The model appears to suggest that the earth creates it’s own energy. Let’s take the two conclusions you’ve hung your hat on:

    3.1 Su=2F
    3.2 Su=3F/2

    Now F =~ 1380 W/m2 flux from the Sun.

    Q1. So 3.1 says 2 x 1380 = 2740 W/m2 upwards from the surface of the earth. Where is that coming from?

    Q2. And 3.2 says 1.5 x 1380 = 2070 W/m2 upwards from the surface of the earth. Where is that coming from?

    Q3. How do you choose between the two constraints?

    Seriously, I think you’ve made a mistake somewhere.

  20. JM June 4, 2008 11:41 am

    David (at #8)

    I understand the greenhouse effect, I also understand thermodynamics and energy balance models.

    I asked you a simple question. The model appears to suggest that the earth creates it’s own energy. Let’s take the two conclusions you’ve hung your hat on:

    3.1 Su=2F
    3.2 Su=3F/2

    Now F =~ 1380 W/m2 flux from the Sun.

    Q1. So 3.1 says 2 x 1380 = 2740 W/m2 upwards from the surface of the earth. Where is that coming from?

    Q2. And 3.2 says 1.5 x 1380 = 2070 W/m2 upwards from the surface of the earth. Where is that coming from?

    Q3. How do you choose between the two constraints?

    Seriously, I think you’ve made a mistake somewhere.

  21. admin June 4, 2008 1:19 pm

    F is the average absorbed radiation of 235W/m2. This is averaged over the whole surface of the earth. Your figure is top of atmosphere instantaneous insolation I think.

    Q3. One of the main choices is if Kirchhoff’s Law applies in this Earth’s situation. That is one of the issues in M’s paper. If models were to accept it, then 3.2 should constrain greenhouse to current levels.

    Didn’t mean to be patronizing. It’s just that the temperature increase over expected black body temperature due to the greenhouse effect is mysterious, and I have seen people struggle with that, and wikipedia is a good introduction.

    http://landshape.org/enm

  22. admin June 4, 2008 1:19 pm

    F is the average absorbed radiation of 235W/m2. This is averaged over the whole surface of the earth. Your figure is top of atmosphere instantaneous insolation I think.

    Q3. One of the main choices is if Kirchhoff’s Law applies in this Earth’s situation. That is one of the issues in M’s paper. If models were to accept it, then 3.2 should constrain greenhouse to current levels.

    Didn’t mean to be patronizing. It’s just that the temperature increase over expected black body temperature due to the greenhouse effect is mysterious, and I have seen people struggle with that, and wikipedia is a good introduction.

    http://landshape.org/enm

  23. JM June 4, 2008 3:50 pm

    “F is the average absorbed radiation of 235W/m2. ”

    I think the question still stands. For the surface to radiate it has to absorb in the first place. So if the relationship is Su = 2F, where does the other half come from?

    btw – I find this whole presentation in terms of flux a bit hard to deal with. Flux is (loosely) energy per unit time, so M has built in a “balance” where everything has to come to equilibrium more or less instantaneously. The model seems to describe reflection more than radiance. Why don’t you express it in energetic (say enthalpy) terms?

    “It’s just that the temperature increase over expected black body temperature due to the greenhouse effect is mysterious”

    Mysterious? In what way? It seems like a simple matter of thermodynamics to me.

  24. JM June 4, 2008 3:50 pm

    “F is the average absorbed radiation of 235W/m2. ”

    I think the question still stands. For the surface to radiate it has to absorb in the first place. So if the relationship is Su = 2F, where does the other half come from?

    btw – I find this whole presentation in terms of flux a bit hard to deal with. Flux is (loosely) energy per unit time, so M has built in a “balance” where everything has to come to equilibrium more or less instantaneously. The model seems to describe reflection more than radiance. Why don’t you express it in energetic (say enthalpy) terms?

    “It’s just that the temperature increase over expected black body temperature due to the greenhouse effect is mysterious”

    Mysterious? In what way? It seems like a simple matter of thermodynamics to me.

  25. admin June 4, 2008 10:06 pm

    “Mysterious? In what way? It seems like a simple matter of thermodynamics to me.”

    If it is not mysterious to you then why the problem with Su=2F. They are equivalent are they not? I am just trying to get to where the issue is for you. Presentation in terms of fluxes is stock standard AFAIK.

    http://landshape.org/enm

  26. admin June 4, 2008 10:06 pm

    “Mysterious? In what way? It seems like a simple matter of thermodynamics to me.”

    If it is not mysterious to you then why the problem with Su=2F. They are equivalent are they not? I am just trying to get to where the issue is for you. Presentation in terms of fluxes is stock standard AFAIK.

    http://landshape.org/enm

  27. JM June 5, 2008 12:14 am

    Let’s make a reasonable assumption. To the first order the only energy entering the system does so in the form of F (ie. from the sun)

    Therefore Su = 2F implies that the surface must (sticking with flux for the moment)

    – reflect 100% of the incident energy (or if you prefer absorb and reradiate 100% of what it absorbs)
    – radiate an additional amount to make up the second half of 2F

    Where does the second half come from?

  28. JM June 5, 2008 12:14 am

    Let’s make a reasonable assumption. To the first order the only energy entering the system does so in the form of F (ie. from the sun)

    Therefore Su = 2F implies that the surface must (sticking with flux for the moment)

    – reflect 100% of the incident energy (or if you prefer absorb and reradiate 100% of what it absorbs)
    – radiate an additional amount to make up the second half of 2F

    Where does the second half come from?

  29. Nick Stokes June 5, 2008 12:58 am

    JM, David’s explanation of the steel greenhouse should explain it. A notional shell around the Earth, 10 m above the surface, transparent to sunlight, but blocking IR. An average of, say 300 W/m2 coming in to the surface (SW), and being radiated outward to space from the shell (LW). But the shell radiates 300 W/m2 in both directions. So the surface actually radiates up 600 W/m2. 300 comes from sunlight, 300 IR from the shell.

  30. Nick Stokes June 5, 2008 12:58 am

    JM, David’s explanation of the steel greenhouse should explain it. A notional shell around the Earth, 10 m above the surface, transparent to sunlight, but blocking IR. An average of, say 300 W/m2 coming in to the surface (SW), and being radiated outward to space from the shell (LW). But the shell radiates 300 W/m2 in both directions. So the surface actually radiates up 600 W/m2. 300 comes from sunlight, 300 IR from the shell.

  31. jae June 5, 2008 1:51 am

    “JM, David’s explanation of the steel greenhouse should explain it. A notional shell around the Earth, 10 m above the surface, transparent to sunlight, but blocking IR. An average of, say 300 W/m2 coming in to the surface (SW), and being radiated outward to space from the shell (LW). But the shell radiates 300 W/m2 in both directions. So the surface actually radiates up 600 W/m2. 300 comes from sunlight, 300 IR from the shell.”

    I have never understood this idea. It completely ignores the other 99% of the gases that are involved and have to be warmed (thermalized). It ignores convection. It ignores clouds. It ignores the fact that the oceans absorb most of the energy that falls on it. IMHO, it is about as simplistic as the K&T cartoon.

  32. jae June 5, 2008 1:51 am

    “JM, David’s explanation of the steel greenhouse should explain it. A notional shell around the Earth, 10 m above the surface, transparent to sunlight, but blocking IR. An average of, say 300 W/m2 coming in to the surface (SW), and being radiated outward to space from the shell (LW). But the shell radiates 300 W/m2 in both directions. So the surface actually radiates up 600 W/m2. 300 comes from sunlight, 300 IR from the shell.”

    I have never understood this idea. It completely ignores the other 99% of the gases that are involved and have to be warmed (thermalized). It ignores convection. It ignores clouds. It ignores the fact that the oceans absorb most of the energy that falls on it. IMHO, it is about as simplistic as the K&T cartoon.

  33. Nick Stokes June 5, 2008 1:56 am

    JM, jae, I should have mentioned that the steel greenhouse is in vacuum. And I meant 10km high. It just illustrates how the surface can emit more than it gets in sunlight, because it exchanges IR with the shell, just as the earth’s surface exchanges IR with the atmosphere. The temperature is higher, but the nett heat flux is the same.

  34. Nick Stokes June 5, 2008 1:56 am

    JM, jae, I should have mentioned that the steel greenhouse is in vacuum. And I meant 10km high. It just illustrates how the surface can emit more than it gets in sunlight, because it exchanges IR with the shell, just as the earth’s surface exchanges IR with the atmosphere. The temperature is higher, but the nett heat flux is the same.

  35. admin June 5, 2008 2:02 am

    jae: It is meant to be a simple theoretical model and not meant to be realistic. There is value in a high level of abstraction, just different value to models at other levels of abstraction. The idea here with the three basic assumptions is questioning whether even the most abstract level of the standard model is right.

    http://landshape.org/enm

  36. admin June 5, 2008 2:02 am

    jae: It is meant to be a simple theoretical model and not meant to be realistic. There is value in a high level of abstraction, just different value to models at other levels of abstraction. The idea here with the three basic assumptions is questioning whether even the most abstract level of the standard model is right.

    http://landshape.org/enm

  37. JM June 5, 2008 12:27 pm

    I’m sorry these explanations don’t wash.

    Firstly let’s note that the model produces an absurd conclusion: Su=2F. The earth simply does not radiate 2x the flux it receives from the sun, it just doesn’t. I could stop right there.

    But moving on. The 300W from the surface and 300W from the “greenhouse” doesn’t work. Flux is a vector quantity, and so it has a direction (in this case up and down). So the correct equation is 300-300 = 0, not 300 + 300 = 600.

    If you want a result like 300+300 = 600, you need to express the model in terms of energy (aka enthalpy) and start using thermodynamics instead of radiation physics. You should be doing this anyway because while there is a law for the conservation of energy, there isn’t one for the “conservation” of flux. No David, flux is not stock standard for thermodynamics, far from it.

    If this presentation truly is an accurate presentation of M’s model, then the model is junk. It is internally inconsistent and produces absurd conclusions.

  38. JM June 5, 2008 12:27 pm

    I’m sorry these explanations don’t wash.

    Firstly let’s note that the model produces an absurd conclusion: Su=2F. The earth simply does not radiate 2x the flux it receives from the sun, it just doesn’t. I could stop right there.

    But moving on. The 300W from the surface and 300W from the “greenhouse” doesn’t work. Flux is a vector quantity, and so it has a direction (in this case up and down). So the correct equation is 300-300 = 0, not 300 + 300 = 600.

    If you want a result like 300+300 = 600, you need to express the model in terms of energy (aka enthalpy) and start using thermodynamics instead of radiation physics. You should be doing this anyway because while there is a law for the conservation of energy, there isn’t one for the “conservation” of flux. No David, flux is not stock standard for thermodynamics, far from it.

    If this presentation truly is an accurate presentation of M’s model, then the model is junk. It is internally inconsistent and produces absurd conclusions.

  39. Jan Pompe June 5, 2008 3:50 pm

    Hi JM,

    First of can you cite a radiation conservation law that says Su = 2F is a contradiction of it?

    Radiative flux is not a vector quantity it is scalar with units joules/m^2/s. It’s actually more like in and out which means it has a sign but not really direction in the sense vectors have direction (consider E = .5*m*v^2 the vector component, velocity, is already squared). Mind you we can treat it as vector by working with radiation pressure which is the average linear momentum of the photons but why complicate things? To add it you are going to have to take the square of the velocity component and you are back where you started.

    A very rough thumbnail: the average insolation is ~1380/4 (1-A) = 241 (no clouds or atmospheric absorption of incoming) the average surface temperature is 288 and the radiation due to that (yes I know it’s not accurate and there is a lot wrong with taking an average this way, but it’s just a sanity check) which gives us a Black body radiation of ~ 390 W/m^2 it’s in the ball park. This part of it really isn’t controversial and to call it junk on this basis is to call all the EBMs ever produced junk even the K & T paper with the cartoon jae mentions and IPCC uses. It offended my intuition the first time I saw it too.

  40. Jan Pompe June 5, 2008 3:50 pm

    Hi JM,

    First of can you cite a radiation conservation law that says Su = 2F is a contradiction of it?

    Radiative flux is not a vector quantity it is scalar with units joules/m^2/s. It’s actually more like in and out which means it has a sign but not really direction in the sense vectors have direction (consider E = .5*m*v^2 the vector component, velocity, is already squared). Mind you we can treat it as vector by working with radiation pressure which is the average linear momentum of the photons but why complicate things? To add it you are going to have to take the square of the velocity component and you are back where you started.

    A very rough thumbnail: the average insolation is ~1380/4 (1-A) = 241 (no clouds or atmospheric absorption of incoming) the average surface temperature is 288 and the radiation due to that (yes I know it’s not accurate and there is a lot wrong with taking an average this way, but it’s just a sanity check) which gives us a Black body radiation of ~ 390 W/m^2 it’s in the ball park. This part of it really isn’t controversial and to call it junk on this basis is to call all the EBMs ever produced junk even the K & T paper with the cartoon jae mentions and IPCC uses. It offended my intuition the first time I saw it too.

  41. JM June 5, 2008 6:04 pm

    Jan “First of can you cite a radiation conservation law ”

    You misunderstood me, I proposed using enthalpy *instead* of flux because there is a conservation law for energy but not for flux. But the question remains, if Su is twice F, where is that coming from?

    “[flux] is actually more like in and out which means it has a sign ”

    Ok let’s work with that. Su does not get to be 2F because of flux heading in opposite directions (signs) does it?

    “to call it junk on this basis is to call all the EBMs ever produced junk ”

    No because this is not an energy balance model, it’s a “flux balance” model and since flux doesn’t have a conservation law I don’t see how the model can be supported or derived on the basis of constraints.

    And intuitively, if Su is defined as “upward flux from the surface” it can’t include “downward flux from the steel greenhouse”

  42. JM June 5, 2008 6:04 pm

    Jan “First of can you cite a radiation conservation law ”

    You misunderstood me, I proposed using enthalpy *instead* of flux because there is a conservation law for energy but not for flux. But the question remains, if Su is twice F, where is that coming from?

    “[flux] is actually more like in and out which means it has a sign ”

    Ok let’s work with that. Su does not get to be 2F because of flux heading in opposite directions (signs) does it?

    “to call it junk on this basis is to call all the EBMs ever produced junk ”

    No because this is not an energy balance model, it’s a “flux balance” model and since flux doesn’t have a conservation law I don’t see how the model can be supported or derived on the basis of constraints.

    And intuitively, if Su is defined as “upward flux from the surface” it can’t include “downward flux from the steel greenhouse”

  43. Nick Stokes June 5, 2008 9:31 pm

    Various confusions here. Yes, flux is a vector, and in this 1D example carries a sign. Let’s say, downward positive. I’ll show that everywhere, the nett flux is zero.

    The sun emits F=300 W/m2 SW. The Earth emits -600 W/m2 LW. The steel cover emits 300 W/m2, up and down equally..
    Above the cover, we have F=300 and -300 LW; total 0
    Below the cover we have F=300 and 300 LW from the cover, and Su=-600 from Earth; total 0
    Everything balances. The Earth is hotter than the cover.

  44. Nick Stokes June 5, 2008 9:31 pm

    Various confusions here. Yes, flux is a vector, and in this 1D example carries a sign. Let’s say, downward positive. I’ll show that everywhere, the nett flux is zero.

    The sun emits F=300 W/m2 SW. The Earth emits -600 W/m2 LW. The steel cover emits 300 W/m2, up and down equally..
    Above the cover, we have F=300 and -300 LW; total 0
    Below the cover we have F=300 and 300 LW from the cover, and Su=-600 from Earth; total 0
    Everything balances. The Earth is hotter than the cover.

  45. Jan Pompe June 5, 2008 11:43 pm

    “Yes, flux is a vector, and in this 1D example carries a sign.”

    This one with a spherical front i.e. an isotropic vector. Now that is interesting. How does this work Nick?

    Scalars have sign too lets call energy in positive instead. We depict this in diagrams with arrows which of course is the same as the way we depict vectors but we shouldn’t be confusing them. The property we are talking about here is the radiation flux density just as much an intensive property as the temperature driving the radiation.

  46. Jan Pompe June 5, 2008 11:43 pm

    “Yes, flux is a vector, and in this 1D example carries a sign.”

    This one with a spherical front i.e. an isotropic vector. Now that is interesting. How does this work Nick?

    Scalars have sign too lets call energy in positive instead. We depict this in diagrams with arrows which of course is the same as the way we depict vectors but we shouldn’t be confusing them. The property we are talking about here is the radiation flux density just as much an intensive property as the temperature driving the radiation.

  47. Nick Stokes June 6, 2008 2:14 am

    Flux is a vector. It has direction. If you want to get into the electromagnetics, it is the Poynting vector.

  48. Nick Stokes June 6, 2008 2:14 am

    Flux is a vector. It has direction. If you want to get into the electromagnetics, it is the Poynting vector.

  49. Jan Pompe June 6, 2008 3:13 pm

    nick I stand corrected it may indeed be thought of as a vector when the radiation is seen to be passing through an infinitesimal (arbitrary) surface. However this as much as anything high lights the fact that contrary to what you said in comment 12 to “The Greenhouse Heat Engine” :

    “3. The Kirchhoff Law. Well, as I have said, it is mis-stated, speaking of extensive quantities (emittances etc) instead of intensive (emissivity). ”

    The emittances or fluxes or radiation energy densities, which are expressed in W/m^2 are an intensive property since the value doesn’t change as you increase the area of the surface through which it passes.

  50. Jan Pompe June 6, 2008 3:13 pm

    nick I stand corrected it may indeed be thought of as a vector when the radiation is seen to be passing through an infinitesimal (arbitrary) surface. However this as much as anything high lights the fact that contrary to what you said in comment 12 to “The Greenhouse Heat Engine” :

    “3. The Kirchhoff Law. Well, as I have said, it is mis-stated, speaking of extensive quantities (emittances etc) instead of intensive (emissivity). ”

    The emittances or fluxes or radiation energy densities, which are expressed in W/m^2 are an intensive property since the value doesn’t change as you increase the area of the surface through which it passes.

  51. JM June 7, 2008 12:18 am

    I don’t think you’re presenting M’s ideas correctly. From his paper comes the following assumption:

    “(d) — The surface heat capacity is equal to zero, the surface emissivity G ε is equal to one, and the surface radiates as a perfect blackbody. ”

    Su = 2F violates this, it implies Su = F.

    Then reading the abstract I came across “In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular planetary average flux optical depth of 1.841″

    That would mean that planets with atmospheres were getting knocked out on an assembly line that make Henry Ford proud – they’d all be the same.

    They aren’t. Both venus and mars are counter examples.

    I’m sticking with ‘junk’.

  52. JM June 7, 2008 12:18 am

    I don’t think you’re presenting M’s ideas correctly. From his paper comes the following assumption:

    “(d) — The surface heat capacity is equal to zero, the surface emissivity G ε is equal to one, and the surface radiates as a perfect blackbody. ”

    Su = 2F violates this, it implies Su = F.

    Then reading the abstract I came across “In Earth-type atmospheres sustained planetary greenhouse effect with a stable ground surface temperature can only exist at a particular planetary average flux optical depth of 1.841″

    That would mean that planets with atmospheres were getting knocked out on an assembly line that make Henry Ford proud – they’d all be the same.

    They aren’t. Both venus and mars are counter examples.

    I’m sticking with ‘junk’.

  53. Nick Stokes June 7, 2008 12:20 am

    Jan, emittance is not really intensive; you can express it as per unit area, but not per unit volume. However, if the intensive/extensive contrast seems unhelpful, it isn’t essential. Let’s just say that emittance and emissivity are quite different.

  54. Nick Stokes June 7, 2008 12:20 am

    Jan, emittance is not really intensive; you can express it as per unit area, but not per unit volume. However, if the intensive/extensive contrast seems unhelpful, it isn’t essential. Let’s just say that emittance and emissivity are quite different.

  55. admin June 7, 2008 7:44 pm

    JM: Both venus and mars are counter examples.
    But your quote specifies “In Earth-type atmospheres …”
    Gee that was easy ;-)

    http://landshape.org/enm

  56. admin June 7, 2008 7:44 pm

    JM: Both venus and mars are counter examples.
    But your quote specifies “In Earth-type atmospheres …”
    Gee that was easy ;-)

    http://landshape.org/enm

  57. Jan Pompe June 7, 2008 11:52 pm

    NIck,

    “emittance is not really intensive;”

    flux density is just as intensive a property as pressure which is also expressed as units/unit area. It follows from the definition of an intensive property which is a property that does not depend on the size of the system. Changing the volume is irrelevant and the area (system size in this case) makes no difference.

    Check it out for yourself in wikipedia if you are uncertain. In any case the two words are used interchangeably by enough folks for Merriam-Webster to include one in the definition of the other, and there is a simple linear relationship between the two if used differently.

  58. Jan Pompe June 7, 2008 11:52 pm

    NIck,

    “emittance is not really intensive;”

    flux density is just as intensive a property as pressure which is also expressed as units/unit area. It follows from the definition of an intensive property which is a property that does not depend on the size of the system. Changing the volume is irrelevant and the area (system size in this case) makes no difference.

    Check it out for yourself in wikipedia if you are uncertain. In any case the two words are used interchangeably by enough folks for Merriam-Webster to include one in the definition of the other, and there is a simple linear relationship between the two if used differently.

  59. Barton Paul Levenson June 9, 2008 9:08 am

    Miskolczi seems to be saying that Kirchhoff’s Law says emission and absorption must be the same. That’s not what it says at all. It says emissivity and absorptivity must be the same (at a given wavelength, for a body in local thermodynamic equilibrium). That’s only one of the many problems with his paper, which really should never have passed peer review.

    And the model presented really does ignore non-radiative fluxes, thus giving a completely wrong answer. Earth’s surface is cooled by two radiative terms (absorption of sunlight in the atmosphere and window radiation) and two non-radiative terms (sensible heat and latent heat). Altogether these mechanisms amount to 209 watts per square meter lost from what would otherwise be the 320 K surface temperature of the Earth. You can’t just ignore those factors if you want to calculate Earth’s surface temperature at all realistically, and Miskolczi does.

    http://members.aol.com/bpl1960

  60. Barton Paul Levenson June 9, 2008 9:08 am

    Miskolczi seems to be saying that Kirchhoff’s Law says emission and absorption must be the same. That’s not what it says at all. It says emissivity and absorptivity must be the same (at a given wavelength, for a body in local thermodynamic equilibrium). That’s only one of the many problems with his paper, which really should never have passed peer review.

    And the model presented really does ignore non-radiative fluxes, thus giving a completely wrong answer. Earth’s surface is cooled by two radiative terms (absorption of sunlight in the atmosphere and window radiation) and two non-radiative terms (sensible heat and latent heat). Altogether these mechanisms amount to 209 watts per square meter lost from what would otherwise be the 320 K surface temperature of the Earth. You can’t just ignore those factors if you want to calculate Earth’s surface temperature at all realistically, and Miskolczi does.

    http://members.aol.com/bpl1960

  61. admin June 9, 2008 11:34 am

    Miskolczi seems to be saying that Kirchhoff’s Law says emission and absorption must be the same.
    Is this clearer? Its from his previous paper http://hps.elte.hu/zagoni/idojaras2004_Vol108_No4.pdf

    As a consequence of the Kirchoff’s law, within the clear atmosphere the
    downward emittance is approximately equal to the absorbed flux density.
    Based on our data set, the global average clear-sky downward atmospheric
    emittance is 311.4 W m–2, while the global average of the absorbed
    radiation by the clear-sky is 311.9 W m–2. This equivalence – for the highly
    variable atmospheric emission spectra and for global scale – was not shown
    before with such a high numerical accuracy.

    the model presented really does ignore non-radiative fluxes
    p3: The net thermal energy to the atmosphere of non-radiative origin is K.

    http://landshape.org/enm

  62. admin June 9, 2008 11:34 am

    Miskolczi seems to be saying that Kirchhoff’s Law says emission and absorption must be the same.
    Is this clearer? Its from his previous paper http://hps.elte.hu/zagoni/idojaras2004_Vol108_No4.pdf

    As a consequence of the Kirchoff’s law, within the clear atmosphere the
    downward emittance is approximately equal to the absorbed flux density.
    Based on our data set, the global average clear-sky downward atmospheric
    emittance is 311.4 W m–2, while the global average of the absorbed
    radiation by the clear-sky is 311.9 W m–2. This equivalence – for the highly
    variable atmospheric emission spectra and for global scale – was not shown
    before with such a high numerical accuracy.

    the model presented really does ignore non-radiative fluxes
    p3: The net thermal energy to the atmosphere of non-radiative origin is K.

    http://landshape.org/enm

  63. sadunkal June 18, 2008 5:40 pm

    Could you sum all this up for a non-scientist please… Is the Miskolczi paper confirmed so far..?

    And is there a long list of peer-reviewed papers somewhere which contradict the “consensus” ? I’m trying to show a scientific-debate-denialist that the science isn’t settled yet…

    Thank you.

    http://sadunkal.blogspot.com

  64. sadunkal June 18, 2008 5:40 pm

    Could you sum all this up for a non-scientist please… Is the Miskolczi paper confirmed so far..?

    And is there a long list of peer-reviewed papers somewhere which contradict the “consensus” ? I’m trying to show a scientific-debate-denialist that the science isn’t settled yet…

    Thank you.

    http://sadunkal.blogspot.com

  65. admin June 19, 2008 7:56 am

    Hello sadunkal. Have a look at this link http://members.shaw.ca/sch25/FOS/Climate_Change_Science.html for a list of issues.

    http://landshape.org/enm

  66. admin June 19, 2008 7:56 am

    Hello sadunkal. Have a look at this link http://members.shaw.ca/sch25/FOS/Climate_Change_Science.html for a list of issues.

    http://landshape.org/enm