SEARCH BLOG: Global Warming
Climate Science has a couple of interesting articles recently posted.
The first one postulates that oceans, as giant heat reservoirs, are a potentially a better indicator of global warming and cooling than surface temperatures:
“• The earth’s heat budget observations, within the limits of their representativeness and accuracy, provide an observational constraint on the radiative forcing imposed in retrospective climate modeling.
• A snapshot at any time documents the accumulated heat content and its change since the last assessment. Unlike temperature, at some specific level of the ocean, land, or the atmosphere, in which there is a time lag in its response to radiative forcing, there are no time lags associated with heat changes.
• Since the surface temperature is a two-dimensional global field, while heat content involves volume integrals, as shown by Eq. (1), the utilization of surface temperature as a monitor of the earth system climate change is not particularly useful in evaluating the heat storage changes to the earth system. The heat storage changes, rather than surface temperatures, should be used to determine what fraction of the radiative fluxes at the top of the atmosphere are in radiative equilibrium. Of course, since surface temperature has such an important impact on human activities, its accurate monitoring should remain a focus of climate research (Pielke et al. 2002a)."
I have to admit that I've struggled a quite bit with this one... largely because I didn't have any scientific training in this area. First, I didn't quite understand how "the heat storage changes" would be accurately measured on a global, three-dimensional basis for the oceans... or even the nature of those measurements unless it is temperature changes. My first inclination was to view this information as telling me that because the oceans act as a giant heat reservoir, atmospheric temperatures are moderated by that effect and that was the importance. But Dr. Pielke was quick to reiterate the conclusions above from the paper as the important points.
The concept is intriguing because oceans are far less susceptible to weather fluctuations and short-temperature changes found in the atmosphere (just ask someone who lives in Michigan about that) which are often pointed to as "proof" of global warming or cooling. With this alternative, it is all about whether the oceanic heat storage is level, increasing or decreasing.
Therefore, I posed the question of reliability and timeliness of using changes in the oceans' heat storage as a measure of global warming/cooling at the Climate Science site and got this response from Dr. Pielke late last night:
"Hi Bruce - The paper
Willis, J.K., D. Roemmich, and B. Cornuelle, 2004: Interannual variability in upper ocean heat content, temperature, and thermosteric expansion on global scales. J. Geophys. Res., 109, C12036, doi: 10.1029/2003JC002260.
discusses in depth the accuracy in which the ocean heat content can be measured.
This data quite accurately samples the upper ocean."
While I am working through this 13-page paper, I have no doubt that my questions will be answered and that is why I recommend that you take the time to learn about this novel approach, if you are concerned about climate change and global warming or cooling.
Dr. Pielke has been quite helpful in getting me to better understand this issue.
The second article poses this hypothesis:
One possible cause of the linear increase [in temperature] may be that the Earth is still recovering from the Little Ice Age. World glaciers and sea ice in the Arctic Ocean have been receding since 1800 or earlier; these are not just recent phenomena. It seems to me that most climate researchers are so caught up in the CO2 effect, the Little Ice Age has been all but forgotten.
It is urgent that natural changes be correctly identified and removed accurately from the presently ongoing changes in order to find the contribution of the greenhouse effect. Some details are given at: http://www.iarc.uaf.edu/highlights/2007/akasofu_3_07/index.php
As I have said before, "Nothing is ever as simple as it first seems." ... and I hope I got it right this time.