by Dennis Ambler
With the current claims yet again of “record temperatures” it may be of interest to look again at this Q & A from James Hansen in 2005. It is still on the website.
Here are a few extracts:
The Elusive Absolute Surface Air Temperature (SAT)
Q. What exactly do we mean by SAT ?
A. I doubt that there is a general agreement how to answer this question. Even at the same location, the temperature near the ground may be very different from the temperature 5 ft above the ground and different again from 10 ft or 50 ft above the ground. Particularly in the presence of vegetation (say in a rain forest), the temperature above the vegetation may be very different from the temperature below the top of the vegetation. (more…)