Monday, May 21, 2018

Latest Ocean Heat Content Data

Global warming continues.

The data for ocean heat content for the first quarter of this year came out the other day for the global regions 0-700 meters and 0-2000 meters. They're warmer. Recall that changes in ocean heat content are the best way to detect the planet's energy imbalance -- over 90% of the heat trapped by our greenhouse gases finds it way into the ocean.

After some spreadsheet fun I get the following:


W=watts, J=joules, m=meters; yrs=years; Z=zetta=1021; T=tera=1012.

Note that the 0-700 m record is almost 5 times longer than the 0-2000 m record, so even though it's about 3 times smaller (in volume) it's not too surprising it's absorbed more heat over its record length. 

The uncertainties don't include autocorrelation -- the reality that one quarter isn't independent of the previous quarter, because a warm quarter is more likely to follow a warm quarter etc -- because I'm lazy and because I'm still not quite sure how to include it for the uncertainties of a 2nd-order polynomial fit. (Anyone know? Can you do it quick and dirty by using the effective sample size neff as in equation 9 of this document by Tom Wigley?)

Lots of graphs can be found here.



(In my calculations I've only included the Argo data for the 0-2000 m region, which starts in 2005, shown in red in this last graph.)

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