Writing in the October 1 issue of Nature, David Victor and Charles Kennel, both of the University of California, San Diego, argue for pegging climate policy to a new «array of planetary vital signs,» such
as changes in the heat content of the oceans.
This
includes changes in heat content of the lithosphere (Beltrami et al., 2002), the atmosphere (e.g., Trenberth et al., 2001) and the total heat of fusion due to melting of i) glaciers, ice caps and the Antarctic and Greenland Ice Sheets (see Chapter 4) and ii) arctic sea ice (Hilmer and Lemke, 2000).
[Response: Hi Roger, Please point me to one study anywhere in the literature which has used the surface temperature record to
infer changes in the heat content of the atmosphere.
Instead, they discuss new ways of playing around with the aerosol judge factor needed to explain why 20th - century warming is about half of the warming expected for increased in GHGs; and then expand their list of fudge factors to include smaller volcanos, stratospheric water vapor (published with no estimate of uncertainty for the predicted change in Ts), transfer of heat to the deeper ocean (
where changes in heat content are hard to accurately measure), etc..
Given the implications for interpretation and application of satellite data, we used model output to gauge how well
interannual changes in heat content (HC) can be inferred indirectly from other fields.
To place the changes of ocean heat content in perspective, Figure 5.4 provides updated estimates of
the change in heat content of various components of the Earth's climate system for the period 1961 to 2003 (Levitus et al., 2005a).
The average temperature changes are not the same (because of the different thickness of the layers), but
the changes in heat content are — what the upper layer loses in heat, the lower gains.
Changes in the heat content of the oceans.
where H is the heat content of the land - ocean - atmosphere system and T ′ is the change in surface temperature in response to
a change in heat content.....
Of course,
change in heat content is related to change in temperature by the heat capacity.
And since this flux has been very steady for a very long time, it can't be the source of
the change in heat content.
A change in the entropy of a system is caused by
a change in its heat content, where the change of entropy is equal to the heat change divided by the average absolute temperature (Ta):
Changes in the heat content of the deep ocean are thus far more sensitive to the air - sea thermal interchanges than previously considered.
At that point you try and measure
changes in heat content of the upper ocean, more precisely, the flow of energy into and out of the upper ocean by measuring the change in heat content over time.
These records show changes in some of the major currents, including
a change in the heat content of the Kuroshio Extension, a warm - water current off of the coast of Japan.
Figure 4 shows the same data as in Figure 3, except expressed as a temperature change rather than as
a change in heat content.»
However, the major conclusions shown are about
the change in heat content (temperature) estimates.
So I went off to see what
the change in the heat content of the ocean has looked like over the period of record.