Although the webserver file for the UAH dataset has not been updated yet, the man who is “in the know” because he’s a major part of the process has released the December UAH global lower troposphere temperature anomaly value. It is 0.18°C down from .254°C the previous month.
2008 10 0.166
2008 11 0.254
2008 12 0.180
Here is what Dr. Spencer had to say on his website today:
Latest Global Average Tropospheric Temperatures
Since 1979, NOAA satellites have been carrying instruments which measure the natural microwave thermal emissions from oxygen in the atmosphere. The signals that these microwave radiometers measure at different microwave frequencies are directly proportional to the temperature of different, deep layers of the atmosphere. Every month, John Christy and I update global temperature datasets that represent the piecing together of the temperature data from a total of eleven instruments flying on eleven different satellites over the years. As of 2008, our most stable instrument for this monitoring is the Advanced Microwave Sounding Unit (AMSU-A) flying on NASA’s Aqua satellite.
The graph above represents the latest update; updates are usually made within the first week of every month. The smooth curve in the graph is a fourth-order polynomial fit to the data, which smooths out the large amount of monthly variability in the data and helps reveal the underlying ‘trends’. (There is no claim that this curve has any predictive power for the coming months or years.)