Human influence on tropospheric temperature

Because two well known skeptics, doctors Christy and Spencer, live in Huntsville who specialize in tropospheric data analysis, this caught my eye and hopefully @wxman :

Human influence on the seasonal cycle of tropospheric temperature | Science

Anthropogenic climate change has become clearly observable through many metrics. These include an increase in global annual temperatures, growing heat content of the oceans, and sea level rise owing to the melting of the polar ice sheets and glaciers. Now, Santer et al. report that a human-caused signal in the seasonal cycle of tropospheric temperature can also be measured (see the Perspective by Randel). They use satellite data and the anthropogenic “fingerprint” predicted by climate models to show the extent of the effects and discuss how these changes have been caused.
. . . <bunch of good stuff> . . .
CONCLUSION
Our results suggest that attribution studies with the seasonal cycle of tropospheric temperature provide powerful and novel evidence for a statistically significant human effect on Earth’s climate. We hope that this finding will stimulate more detailed exploration of the seasonal signals caused by anthropogenic forcing.​

I'll ask if I can get a copy of the paper. If not, the paywall is not that high. Regardless, the abstract (be careful!!!) makes an interesting assertion that the winter temperatures are remaining constant but the summer temperatures have increased, the "Tac".

Bob Wilson

 

I got a nice reply. I'll read the paper and supporting data later this evening.

The team used a climate model (actually several) to define a base signal of tropospheric temperature changes at different altitudes corresponding to the microwave sounder. The model(s) include volcanic and solar irradiance. Then using the RSS, NOAA, and UAH dataset calculated the offset from the model(s) giving the noise, man-made noise. So rather than looking at global temperature changes, they looked at seasonal and the temperature differences between high and low troposphere (TMT).

Somethings were obvious such as the seasonal variability between winter and summer is higher in the land dominated Northern hemisphere versus sea dominated Southern hemisphere. But the greater summer temperatures appear to be due to the land drying. This provides higher temperature extremes in the summer, not so much in the winter.

Unexpected, the microwave data shows significant differences with UAH 6.0 and the previous version 5.6 that agrees with RSS and NOAA. This was not a primary goal of this paper but fell out of the signal-to-noise ratio analysis.

This is from my first fast reading. I need to go back and re-read the paper to dive into some of the references.

Bob Wilson