The global temperature bounced upward in March. March anomaly is +0.11 C. Below is the UAH satellite temperature anomaly record since the satellite program began.–Chart courtesy of Dr Spencer. (click on the chart for clarity)
Dr Spencer provides some background on these global temperature measurments:
Since 1979, NOAA satellites have been carrying instruments that 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. Contrary to some reports, the satellite measurements are not calibrated in any way with the global surface-based thermometer records of temperature. They instead use their own on-board precision redundant platinum resistance thermometers calibrated to a laboratory reference standard before launch.
These UAH satellite temperatures are the “gold standard”.
The revisionism that goes on with the so-called respected organizations that report surface temperature invalidates their work in my view. For the those wondering what I mean, it is this. Because their charts are a matter of record, we can see how they have on various occasions revised the charts. The temperatures in the 1930tys have been lowered and the more recent temperatures have been raised. All of this is to give the illusion that the recent years are warmer and that the rate of increase is more dramatic. Note the NASA (GISS) chart below. The data as presented in 1980 are plotted in blue. The data as presented in 2010 are in red.
CRU did something similar. See chart below showing the revisions made between 2001 and 2010.