An Interesting Admission And An Error By Gavin Schmidt

Update 28 May 2012 – Gavin’s Responses and My Replies

Gavin responds in OHC Model/Obs Comparison Errata comment #17 by Ken Lambert where he tries (unsuccessfully) to spin that he was talking about the ability to measure the TOA radiative fluxes well enough to close with the upper ocean heat budget changes on annual time periods [I agree on the difficulty of measuring radiative fluxes].  However, within the uncertainty of the upper ocean heat data, it is an accurate measure of what the annual average TOA radiative imbalance is as the ocean itself does the time and space integration.

Gavin wrote originally that

Assuming that there is a direct one-to-one comparison on annual timescales to TOA imbalance is not valid.

I showed he was wrong. He is still in error. He disingenuously writes in his comment that

 “….variations in OHC-700m metric can come from many sources: spatial coverage, ocean internal variability, differences in surface heat flux etc”

Gavin also responds to Ken Lambert’s comment # 18 with

 “There are changes on land, in ice, in the Arctic, in the deep ocean, in the water storage etc. that on a year to year basis are significant.”

Ocean internal variability does not matter except for heat that would be transferred deeper than 700m. Surface heat fluxes are accounted for in the heating of the ocean, as the troposphere has not changed its global heat content in a number of years (e.g. see).  In terms of spatial coverage, such a limitation of coverage is not reported by the Argo research team. Indeed, if that were a problem, I am sure they would be requesting more profilers.  ;-)

The land and sea ice are very small components of the heat within the climate system, as even his colleague Jim Hansen agrees with.  Gavin’s comment about the Arctic makes no sense. Finally, heat transfer to deeper in the ocean should be seen in the Argo network, as has been discussed previously on my weblog. In any case, how much heat does he conclude can be transferred to that depth in any one year?

Gavin finally states that

Our model suggests that OHC-700m is strongly correlated (not perfectly) to the TOA imbalance and is ~90% of the total heat content change.

If he really wanted a scientifically constructive debate, he would present the magnitude of the terms in heat budget outside of the upper ocean. He does agree, in the above statement, that ~90%  of the OHC is in the upper 700m of the ocean. Thus at the very end of his comment, he admits that

There is a direct one-to-one comparison on annual timescales to TOA imbalance.

Gavin, instead of admitting he was wrong (as we are all some of the time), just persists in his erroneous statement instead of modifying it.

On the other issue that Gavin commented on (#20), he writes

Just FWIW, RP Sr’s post today is wrong on both counts. The trend in the historical runs (1951-1999) was 0.15 x 10^22 J/yr, not the trend in the control runs.

However, Gavin wrote in the original post that

Not sure what is going there. Possibly it could be an issue with control drift. I did a quick analysis of the 1951-1999 trend in the GISS-ER ensemble mean total OHC and it is 0.15 x 10^22 J/yr.

I interpreted the above sentence to mean that the “control drift” was “0.15 x 10^22 J/yr”.  That seemed to be what he is referring to with the use of “it”. If his writing was just sloppy, what is the magnitude of the “control drift” in the GISS runs for the upper ocean heat content in Joules per decade?

I am glad that Gavin has presented his feedback to the insightful comments by Ken Lambert, as this is further documenting the limitation in the quantitative skill of the GISS model to predict global climate system heat changes.

******************************ORIGINAL POST**********************

In Gavin Schmidt’s post

OHC Model/Obs Comparison Errata

he presents an interesting admission and an erroneous statement. First his admission

1. In a reply to the comment by Paul S on Figure 1 in Cai et al. 2010  [#15] on his post

Gavin writes

[Response: Not sure what is going there. Possibly it could be an issue with control drift. I did a quick analysis of the 1951-1999 trend in the GISS-ER ensemble mean total OHC and it is 0.15 x 10^22 J/yr. (0.07 to 0.23  x 10^22 J/yr range within the ensemble). It's possible that Cai et al is only showing a single run? - gavin]

This documents a linear bias in the GISS multi-decadal model runs of 1.5 x 10^22 J per decade (0.7 to 2.3 x10^22 J per decade).

2. In response to an excellent  comment by Ken Lambert [#17], Gavin writes

Assuming that there is a direct one-to-one comparison on annual timescales to TOA imbalance is not valid.

Gavin is in error as shown in the paper

Ellis et al. 1978: The annual variation in the global heat balance of the Earth. J. Geophys. Res., 83, 1958-1962

and as I have discussed in my paper

Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer.  Meteor. Soc., 84, 331-335.

There is a direct relationship between ocean heat content changes and TOA radiative imbalances even on the annual time scale.

I have reproduced below the figure from that paper that shows a direct relationship between the TOA radiative imbalance and ocean heat content is valid. I posted on this recently in

A Summary Of Why The Global Annual-Average Surface Temperature Is A Poor Metric To Diagnose Global Warming

Ken Lambert in his next comment [#18] succinctly also refutes Gavin when he writes

How else is the TOA energy imbalance globally stored in the Earth system if not on the one to one time scale at which it occurs?

It appears that Gavin incompletely appreciates the value of the upper ocean heat storage as a metric to diagnose the magnitude of global warming.  

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