Counterpoints at:
http://www.nature.com/ngeo/journal/v1/n6/abs/ngeo208.html
Nature Geoscience 1, 399 - 403 (2008)
Published online: 25 May 2008 | doi:10.1038/ngeo208
Subject Category: Climate science
Warming maximum in the tropical upper troposphere deduced from thermal winds
Robert J. Allen & Steven C. Sherwood
Abstract
Climate models and theoretical expectations have predicted that the upper troposphere should be warming faster than the surface. Surprisingly, direct temperature observations from radiosonde and satellite data have often not shown this expected trend. However, non-climatic biases have been found in such measurements. Here we apply the thermal-wind equation to wind measurements from radiosonde data, which seem to be more stable than the temperature data. We derive estimates of temperature trends for the upper troposphere to the lower stratosphere since 1970. Over the period of observations, we find a maximum warming trend of 0.65plusminus0.47 K per decade near the 200 hPa pressure level, below the tropical tropopause. Warming patterns are consistent with model predictions except for small discrepancies close to the tropopause. Our findings are inconsistent with the trends derived from radiosonde temperature datasets and from NCEP reanalyses of temperature and wind fields. The agreement with models increases confidence in current model-based predictions of future climate change.
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http://www.ossfoundation.us/projects/environment/global-warming/myths/troposphere-not-warming
Troposphere Not Warming
This is a common denialist/skeptic meme. The reality is that while there are significant complexities in the tropospheric measurements and models, homogenized analysis indicates that generally the troposphere is doing what is expected of it in accord with the various models and general expectations.
Troposphere Not Warming
Santer et al 2008 Fig. 6
Satellite measurements have had their problems and continued observation and modeling aids in correcting for aberrations, errors, and biases. Reasonably dealing with biases in data, and aberrations, are important to assessing the reasonability of a particular data set. This of course needs to be considered with other data sets and models. This is an inter-dynamic process, and continues to improve as more and more scientists examine the models and observations.
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http://www.realclimate.org/index.php/archives/2008/05/tropical-tropopshere-ii/
24 May 2008
Tropical tropospheric trends again
Back in December 2007, we quite heavily criticised the paper of Douglass et al (in press at IJoC) which purported to show that models and data were inconsistent when it came to the trends in the tropical troposphere. There were two strands to our critique: i) that the statistical test they used was not appropriate and ii) that they did not acknowledge the true structural uncertainty in the observations. Most subsequent discussion has been related to the statistical issue, but the second point is perhaps more important.
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http://www.realclimate.org/index.php/archives/2008/10/tropical-tropopshere-iii/
12 October 2008
Tropical tropospheric trends again (again)
— gavin @ 6:45 PM - (Italian)
Many readers will remember our critique of a paper by Douglass et al on tropical tropospheric temperature trends late last year, and the discussion of the ongoing revisions to the observational datasets. Some will recall that the Douglass et al paper was trumpeted around the blogosphere as the definitive proof that models had it all wrong.
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Hugh Bartlett said:
Check this out for June 2009:
http://www.drroyspencer.com/latest-global-temperatures/
Okay, it is the lower atmosphere, not surface temperature. But this is by satellite data, which is less prone to the vagaries in measurement technology that plague surface meassurements (urban heat island effects, etc.). The baseline is 1979-1998, the period of greatest surface warming, but if there is a greenhouse effect, it is in the atmosphere that it would be manifesting itself. There, the trend is basically flatlined over the last 30 years.
