Tuesday, July 20, 2010

Monitoring global temperatures daily.

I've been running a macro each day to monitor JAXA sea ice. I've added to it facilities for updating UAH satellite temperatures. Now I've added an automatically updated plot of the 5 main global temperature indices, HADCrut3, Gistemp, NOAA-NCDC, UAH and MSU-RSS. Of course, these are each only updated monthly, but the macro checks each day for new info, so the plots should remain current. Below the jump:

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:

And now the monthly indices, shown for the last year, and the last four years. They will normally be updated on the same day as the above plots.

Finally, a tracking plot to follow whether 2010 will be a record for any of the indices. Cumulative anomaly just means the cumulative sum of monthly anomalies for 2010. The comparison is to 2005 for GISS and NOAA, and 1998 for the other indices. For GISS and NOAA, 1998 is lightly dotted. Since the absolute value doesn't matter in the comparison, I've started at an arbitrary level, spaced for clarity.  Months are shown with vertical stripes. Details here.


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