Update. Today, 20 Aug, Roy Spencer says:
The bottom line is this: You can rely ONLY upon two channels at the Discover “Temperature Trends” page:
(1) the “Aqua ch.5 v2” channel for global-average mid-tropospheric temperatures, from the AMSU on NASA’s Aqua satellite, and
(2) the “Sea Surface” temperatures, which are averaged over the global ice-free oceans (60N to 60S), from the AMSR-E instrument on Aqua.Do not trust any of the other channels for temperature trend monitoring.
So that seems to say that Ch 5 below is OK, but not Ch 4.
First the daily updates of UAH Channels 4 (troposphere near surface) and 5 (about 14,000 feet or 4 km). I've expressed them as anomalies relative to the average of readings shown on the file (1999-2009 for Ch 4; 2002-2009 for Ch 5). Anomalies are used to take out the seasonal variation, making relative values easier to see. The date shown is the date when the macro was run: