- Ray Pierrehumbert
Certainly interesting - plus a lot of strange weather being reported as well.
You are being a nonconformist in your choice of the more obvious "near surface layer(ch04)" UAH amsu graph.Other websites generally suggest the less obvious 14000ft channel 5, without ever giving an explanation. The message is the same on both.
RSS just published their TLT May anomaly0.588C is the second warmest anomaly since May 1998 - 0.668C.
There's no mystery about the use of channel 5. That channel allows one to plot 20-year highs and lows, which are not available in channel 4.
I find the set up at that site odd. The y axis values appears to be upside down, there's no data for half of the 'controversial' 1998, and there is a temp rise hump in the middle of every year that seems at odds with their data, where the higher temps are Oct - Mar for some years. And, as Nick pointed out, there are more utilities for the channel 05 data than the surface channel (04), which is where the point of controversy is strongest (isn't it?).I'm no expert, so if someone could explain these things, or confirm that they're a bit odd, I'd be grateful.
Just remembered - the 1998 data is truncated because that's when the data stream starts for the current satellite they're using.
The y axis is negative, and the record started in 1998.As for ch 4 vs ch 5, I am not sure. I guess there is more scientific interest in a pure tropospheric signal than one where some land temps may mix in.
The negative nature of the y-axis is because it's not actually showing temperature - it's showing "brightness temperature" which takes a little explanation.And there really is a seasonal variation because (a) different amount of land in northern vs southern hemispheres and (b) eccentricity of Earth's orbit. Compare the seasonal variation of the sea surface chart with that of ch04/ch05. It'll make sense if you think about it.
Thanks for clearing that up for me.The UAH May anomaly has come out.http://www.drroyspencer.com/2010/06/may-2010-uah-global-temperature-update/
The temperature time series at the Met Office has 2010 slightly warmer than 1998... so far.http://hadobs.metoffice.com/hadcrut3/diagnostics/global/nh+sh/
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