Monday, January 17, 2011

Lindzen e-mail to Dessler on 1/14/11

Dear Andy,

It is clear where you are going wrong. You are confusing changes over long periods during which equilibration can occur with fluctuations from which feedbacks can be determined. Note that in order to measure feedbacks from outgoing radiation, one must look at time scales that are short compared to equilibration times (years) but long compared to the action of feedback processes (days). That fluctuations in clouds, volcanos, etc. occur over the relevant time scales is obvious as is the fact that such fluctuations must, of necessity, cause changes in surface temperature. The issue of whether clouds can cause El Nino is a red herring. Incidentally, we have looked at your data. If you restrict yourself to relevant time segments, your r-square goes up greatly, and if you perform an analysis of leads and lags, you too get a negative feedback from fluctuations in outgoing radiation that lag SST (whether you choose segments or your entire record -- though again, r square is much larger for segments). The ambiguities in the choice of segments in Lindzen-Choi 2009 disappear when one uses 2 or 3 month smoothing.

Best wishes,


No comments: