Lucia reported on HadSST June 2009 values, which are out quickly and are surprisingly high given seemingly low RSS values. Lucia:
it looks like the HadSST’s temperature anomalies may finally break their all time high temperature anomalies. The June anomaly of 0.50 C is a big jump up from 0.355C for May:
The preliminary June 2009 HadISST results are a bit of a surprise given that prior RSS results showed a relatively cool June 2009.
I was hoping to do a quick examination of the data, but, as so often in climate science, the comparison took far longer than it should have because of a strange screwup in how the UK Met Office archived the HadISST data. (They double-counted one month in one of their archives – unfortunately the one that I downloaded. I wasted a LOT of time trying to figure out what was going on until I identified the problem. You’d think that some climate scientist somewhere would have noticed that one month occurred twice in the data, but I guess not. I’ll post a bit on this in a comment below. )
I examined HadISST and RSS for the tropics (20S-20N) – partly to simplify things, partly because I’ve been following tropical temperatures. By accident, my first plot was of the HadISST Junes 2009 preliminary in K. Generally one sees plots in anomaly deg C. However, these are derived from absolute temperatures and it never does any harm to squint at data from different directions. So today we’re going to plot in K rather than anomaly deg C.
Here is a plot of the difference – there is obviously a striking asymmetry between SH and NH with 2009 being colder in the NH and warmer in the SH (particularly in the upwelling zones). Squinting back at the 2009 SST plot, it seems relatively cool in the Atlantic hurricane development zone, indicating that 2009 is not likely to have a bumper crop of Atlantic hurricanes.
I did similar plots for RSS TLT and will show a couple. Here is RSS TLT for June 2009 – again in K rather than anomaly deg C. In the K plot, the Sahara is obviously a remarkable anomaly that doesn’t stick out in the anomaly deg C plots.
The June 2009 to June 2005 difference for RSS TLT is far more muted than the corresponding HadISST difference, especially at the edges of the southern tropics. There is an interesting increase in east Africa.
Finally here is a plot of June 2009 lapse rate (over the ocean) which again has an interesting pattern. There is a very low lapse rate at the upwelling zone on the west coast of Africa – presumably related to the warm TLT temperatures over the Sahara.
What does this mean, if anything? Dunno.
The SH-ness of the HadISST increase is interesting because it’s definitely been a cool North American summer. We haven’t used our air conditioner once this year and most days, I’ve worn a light sweater. (I’m a Canadian – I like this sort of weather.) Has it been a warm Australian winter?
We’ve been pretty quick to notice temperature declines in other series and need to be equally attentive to temperature increases. In my opinion, as I’ve observed many times, the pure time series properties of the various temperature series do not permit elaborate conclusions one way or the other on the future course of temperatures – either on the part of Rahmstorf and similar data torturers or on the part of people deriving a morale from relatively little temperature increase over the past decade.