UC (whose comments should always be read attentively) wondered the other day about the effect of taking monthly normals – a step that is routine in much climate analysis as a preliminary to analysis. In the case of Dessler v Spencer, both parties to the litigation work after-taking monthly normals ( “post-normal” statistics, so to speak :) )
I’ve spent a couple of days looking at CERES data without taking normals and present a couple of questions for readers to think about. (I know the answers.) I’d like readers to answer according to their general knowledge and not by looking up or researching.
The first question: the “solar constant” (as measured by CERES) is approximately 340.5 wm-2 (1362/4). What is the variation in average annual incoming solar as measured by CERES?
I’ve temporarily shut off comments on this thread so that you have an opportunity to make your answer without being affected by the answers from other readers. Update: Open now.
Answer: the difference between the annual max and annual min is about 23 wm-2, or about 5 times the 3.8 wm-2 anticipated from doubled CO2, as readers quickly observed. Some people instinctively think about solar variability, but it’s the eccentricity that matters.
Question 2: What is the approximate annual variability in global tropospheric temperature (pick an AMSU lower troposphere level) ? Does the annual temperature maximum coincide with the annual forcing maximum? If not, how much is the phase difference?