Comments on: Surface Temperatures – estimating the SD of the trends http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/ The power of numeracy Tue, 16 Mar 2010 22:03:06 -0500 http://wordpress.org/?v=2.8.6 hourly 1 By: rzsxxbesklq http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/comment-page-1/#comment-179081 rzsxxbesklq Thu, 16 Jul 2009 18:39:57 +0000 http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/#comment-179081 o0jAV8 <a href="http://zdltmlnchnbb.com/" rel="nofollow">zdltmlnchnbb</a>, [url=http://lflbmpvvvjbn.com/]lflbmpvvvjbn[/url], [link=http://mzgtzfwimequ.com/]mzgtzfwimequ[/link], http://hljloxcjhkku.com/ o0jAV8 zdltmlnchnbb, [url=http://lflbmpvvvjbn.com/]lflbmpvvvjbn[/url], [link=http://mzgtzfwimequ.com/]mzgtzfwimequ[/link], http://hljloxcjhkku.com/

]]> By: Franko http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/comment-page-1/#comment-168480 Franko Fri, 08 Aug 2008 11:32:27 +0000 http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/#comment-168480 The trend changes with time. More insight if actual is compared to output of a low pass filter. AR predict, backward and forward, run low pass both ways, and average to remove phase delay. How to interpret the errors, I am not shure. The trend changes with time. More insight if actual is compared to output of a low pass filter. AR predict, backward and forward, run low pass both ways, and average to remove phase delay. How to interpret the errors, I am not shure.

]]> By: Niche Modeling » Example of Simple Linear Regression - global warming trends http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/comment-page-1/#comment-99974 Niche Modeling » Example of Simple Linear Regression - global warming trends Tue, 18 Mar 2008 20:43:16 +0000 http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/#comment-99974 [...] Below are graphs for the last ten years and the trend line for global temperatures for four sources from Anthony Watts over the period January 1998 to February 2008. The simple linear regression line through the points shows the 10 year trend. One of the main claims of the theory of global warming is that greenhouse gases in the atmosphere cause increasing temperatures. If temperatures stop increasing for long enough, while greenhouse gases such as CO2 continue to rise, then we could be justified in not believing the theory. The basic numeracy skill from statistics is the hypothesis test. To set up the test we assume no difference between the datum being tested (called a null hypothesis or H0) and estimate the probability of assuming incorrectly, based on the data. The hypothesis test on these data would be as follows: First, we estimate the expected variability of the trend. The standard deviation of the 10 year trend was estimated directly from the trends over the entire period of data collection according to the robust procedure described here. We also calculate the difference between the IPCC expected trend of 0.2C per decade and observed trend per decade. We then estimate the probability of the observed trend, given an expected trend of 0.2C by comparing the difference and the SD. This gives us the probability of the null hypothesis is rejected, that there is no difference between the predicted and the observed trends. We can estimate the actual probability for each of the global temperature indices with the R function pnorm() as follows: [...] [...] Below are graphs for the last ten years and the trend line for global temperatures for four sources from Anthony Watts over the period January 1998 to February 2008. The simple linear regression line through the points shows the 10 year trend. One of the main claims of the theory of global warming is that greenhouse gases in the atmosphere cause increasing temperatures. If temperatures stop increasing for long enough, while greenhouse gases such as CO2 continue to rise, then we could be justified in not believing the theory. The basic numeracy skill from statistics is the hypothesis test. To set up the test we assume no difference between the datum being tested (called a null hypothesis or H0) and estimate the probability of assuming incorrectly, based on the data. The hypothesis test on these data would be as follows: First, we estimate the expected variability of the trend. The standard deviation of the 10 year trend was estimated directly from the trends over the entire period of data collection according to the robust procedure described here. We also calculate the difference between the IPCC expected trend of 0.2C per decade and observed trend per decade. We then estimate the probability of the observed trend, given an expected trend of 0.2C by comparing the difference and the SD. This gives us the probability of the null hypothesis is rejected, that there is no difference between the predicted and the observed trends. We can estimate the actual probability for each of the global temperature indices with the R function pnorm() as follows: [...]

]]> By: admin http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/comment-page-1/#comment-98790 admin Wed, 12 Mar 2008 18:51:00 +0000 http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/#comment-98790 Hi Lucia. Yes, bouncing statistical analysis around is a great way to blog. There is value in different people checking things different ways. Although, neither AR models or an empirical approach captures the full variability due to long term persistence (LTP). Its closer to 2.5 times the variability derived from the IID result. See <a href="http://landshape.org/enm/?p=13">here</a>. Cheers Hi Lucia. Yes, bouncing statistical analysis around is a great way to blog. There is value in different people checking things different ways.

Although, neither AR models or an empirical approach captures the full variability due to long term persistence (LTP). Its closer to 2.5 times the variability derived from the IID result. See here. Cheers

]]> By: lucia http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/comment-page-1/#comment-98769 lucia Wed, 12 Mar 2008 16:52:23 +0000 http://landshape.org/enm/surface-temperatures-estimating-the-sd-of-the-trends/#comment-98769 Ohhh!!! We are all starting to get the same results.. different ways! (This is the upside to minor disagrements.) Way cool. :) Ohhh!!! We are all starting to get the same results.. different ways! (This is the upside to minor disagrements.)

Way cool. :)

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