Source: New research brings satellite measurements and global climate models closer | UW Today To hang a record on one instrument, NOAA-9, is always risky. But there is another factor, the daily temperature change (i.e., "diurnal drift corrections".) This is an area cited in this abstract: Source: An Error Occurred Setting Your User Cookie, March 2015. It makes sense that ocean waters would have well defined, predictable diurnal effects. But land would be the challenge if nothing else because of: water content material angle biological cover This sounds very interesting, a technical challenge to puzzle out. Interesting because this is also a meteorology effect. Climate and weather touching the same phenomena. Bob Wilson ps. Found this interesting read: http://www.atmos.uw.edu/~qfu/Publications/jtech.pochedley.2015.pdf
Estimating temperature of a layer of the atmosphere, while looking down through all the layers above, based on microwave 'brightness', has always been a challenge. It does offer some potential advantages to surface thermometers, so it's a good thing that several groups make the effort. Coverage is truly global (except at high latitudes the 'looking down' angle is steep because the birds don't go there). The initial data is archived (somewhere) so that when the retrieval algorithms are improved, the entire time series can be redone. The record shows much stronger response to ENSO than surface thermometers, this is unexplained and limits its value as a time series. Also, it refers to a place where average T is about -25 and oxygen is scarce. In no way is it a record of T 'where you live'.
