UPDATE (April 16 2010) WITH RESPONSE BY KEVIN TRENBERTH PRESENTED WITH HIS PERMISSION
I do not agree with your comments. We are well aware that there are well over a dozen estimates of ocean heat content and they are all different yet based on the same data. There are clearly problems in the analysis phase and I don’t believe any are correct. There is a nice analysis of ocean heat content down to 2000 m by von Schuckmann, K., F. Gaillard, and P.-Y. Le Traon 2009: Global hydrographic variability patterns during 2003–2008, /J. Geophys. Res.,/ *114*, C09007, doi:10.1029/2008JC005237. but even those estimates are likely conservative. The deep ocean is not
well monitored and nor is the Arctic below sea ice. That said, there is a paper in press (embargoed) that performs an error analysis of ocean heat content.
Our article highlights the discrepancies that should be resolved with better data and analysis, and improved observations must play a key role.
Thank you for your response. I am aware of the debate on the quality of the ocean data, and have blogged on the von Schuckman et al paper. Since 2005, however, the data from 700m to the surface seems robust spatially (except under the arctic sea ice as you note). An example of the coming to agreement among the studies is Figure 2 in
Leuliette, E. W., and L. Miller (2009), Closing the sea level rise budget with altimetry, Argo, and GRACE, Geophys. Res. Lett., 36, L04608, doi:10.1029/2008GL036010.
We both agree on the need for further data and better analyses. I have posted on this issue; e.g. see
However, I do not see how such large amounts of heat could have transited to depths below 700m since 2005 without being detected.
I am very supportive, however, of your recognition that it is heat in Joules that we should be monitoring as a primary metric to monitor global warming. Our research has shown significant biases in the use of the global average surface temperature for this purpose; e.g.
Pielke Sr., R.A., C. Davey, D. Niyogi, S. Fall, J. Steinweg-Woods, K. Hubbard, X. Lin, M. Cai, Y.-K. Lim, H. Li, J. Nielsen-Gammon, K. Gallo, R. Hale, R. Mahmood, S. Foster, R.T. McNider, and P. Blanken, 2007: Unresolved issues with the assessment of multi-decadal global land surface temperature trends. J. Geophys. Res., 112, D24S08, doi:10.1029/2006JD008229. http://pielkeclimatesci.files.wordpress.com/2009/10/r-321.pdf
Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114,
D21102, doi:10.1029/2009JD011841. http://pielkeclimatesci.files.wordpress.com/2009/11/r-345.pdf
Would you permit me to post your reply below along with my response on my weblog.
KEVIN’S FURTHER REPLY
Roger you may post my comments. The V.s paper shows quite a lot of heat below 700 m.
MY FURTHER RESPONSE
Thanks! On the V.s et al paper, lets assume their values since 2005 deeper than 700m are correct [which I question since I agree with you on the data quality and coverage at the deeper depths]. However, if they are correct, how much of this heat explains the “missing” heat?
It would be useful (actually quite so) if you would provide what is the missing heat in Joules.
END OF UPDATE
There was a remarkable press release 0n April 15 from the NCAR/UCAR Media Relations titled
The article starts with the text
BOULDER—Current observational tools cannot account for roughly half of the heat that is believed to have built up on Earth in recent years, according to a “Perspectives” article in this week’s issue of Science. Scientists at the National Center for Atmospheric Research (NCAR) warn in the new study that satellite sensors, ocean floats, and other instruments are inadequate to track this “missing” heat, which may be building up in the deep oceans or elsewhere in the climate system.
“The heat will come back to haunt us sooner or later,” says NCAR scientist Kevin Trenberth, the lead author. “The reprieve we’ve had from warming temperatures in the last few years will not continue. It is critical to track the build-up of energy in our climate system so we can understand what is happening and predict our future climate.”
Excerpts from the press release reads
“Either the satellite observations are incorrect, says Trenberth, or, more likely, large amounts of heat are penetrating to regions that are not adequately measured, such as the deepest parts of the oceans. Compounding the problem, Earth’s surface temperatures have largely leveled off in recent years. Yet melting glaciers and Arctic sea ice, along with rising sea levels, indicate that heat is continuing to have profound effects on the planet.”
“A percentage of the missing heat could be illusory, the result of imprecise measurements by satellites and surface sensors or incorrect processing of data from those sensors, the authors say. Until 2003, the measured heat increase was consistent with computer model expectations. But a new set of ocean monitors since then has shown a steady decrease in the rate of oceanic heating, even as the satellite-measured imbalance between incoming and outgoing energy continues to grow.”
Some of the missing heat appears to be going into the observed melting of ice sheets in Greenland and Antarctica, as well as Arctic sea ice, the authors say.
Much of the missing heat may be in the ocean. Some heat increase can be detected between depths of 3,000 and 6,500 feet (about 1,000 to 2,000 meters), but more heat may be deeper still beyond the reach of ocean sensors.”
Trenberth’s [and co-author, NCAR scientist John Fasullo], however, are grasping for an explanation other than the actual real world implication of the absence of this heat.
- First, if the heat was being sequestered deeper in the ocean (lower than about 700m), than we would have seen it transit through the upper ocean where the data coverage has been good since at least 2005. The other reservoirs where heat could be stored are closely monitored as well (e.g. continental ice) as well as being relatively small in comparison with the ocean.
- Second, the melting of glaciers and continental ice can be only a very small component of the heat change (e.g. see Table 1 in Levitus et al 2001 “Anthropogenic warming of Earth’s climate system”. Science).
Thus, a large amount heat (measured as Joules) does not appear to be stored anywhere; it just is not there.
There is no “heat in the pipeline” [or “unrealized heat”] as I have discussed most recently in my post
Kevin Trenberth and John Fasullo are not recognizing that the diagnosis of upper ocean heat content changes (with it large mass) makes in an effective integrator of long term radiative imbalances of the climate system as I discussed in my papers
Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55.
Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335.
The assessment of ocean heat storage changes in Joules is a much more robust methodology to assess global warming than the use of small changes in the satellite diagnosis of radiative forcing from the satellites which have uncertainties of at least the same order. Trenberth and Fasullo need to look more critically at the satellite data as well as propose how heat in Joules could be transported deep into the ocean without being seen.
I am contacting Kevin to see if he would respond to my comments on this news article (and his Science perspective) in a guest post on my weblog.