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Posted on 08/14/2009 7:17:05 AM PDT by decimon
Physicists at the University of Rochester have combed through data from satellites and ocean buoys and found evidence that in the last 50 years, the net flow of heat into and out of the oceans has changed direction three times.
These shifts in the balance of heat absorbed from the sun and radiated from the oceans correlate well with past anomalies that have been associated with abrupt shifts in the earth's climate, say the researchers. These anomalies include changes in normal storm intensities, unusual land temperatures, and a large drop in salmon populations along the western United States.
The physicists also say these changes in ocean heat-flow direction should be taken into account when predicting global climate because the oceans represent 90 percent of the total heat in the earth's climate system.
The study, which will appear in an upcoming issue of Physics Letters A, differs from most previous studies in two ways, the researchers say. First, the physicists look at the overall heat content of the Earth's climate system, measuring the net balance of radiation from both the sun and Earth. And second, it analyzes more completely the data sets the researchers believe are of the highest quality, and not those that are less robust.
"These shifts happened relatively abruptly," says David Douglass, professor of physics at the University of Rochester, and co-author of the paper. "One, for example, happened between 1976 and 1977, right when a number of other climate-related phenomenona were happening, such as significant changes in U. S. precipitation."
Douglass says the last oceanic shift occurred about 10 years ago, and that the oceans are currently emitting slightly more radiation than they are receiving.
The members of the team, which includes Robert Knox, emeritus professor of physics at the University, believe these heat-flux shifts had previously gone unnoticed because no one had analyzed the data as thoroughly as the Rochester team has.
The team believes that the oceans may change how much they absorb and radiate depending on factors such as shifts in ocean currents that might change how the deep water and surface waters exchange heat. In addition to the correlation with strange global effects that some scientists suspect were caused by climate shifts, the team says their data shows the oceans are not continuously warming—a conclusion not consistent with the idea that the oceans may be harboring "warming in the pipeline." Douglass further notes that the team found no correlation between the shifts and atmospheric carbon dioxide concentration.
"An interesting aspect of this research is that no reference to the surface temperature itself is needed," says Knox. "The heat content data we used, gathered by oceanographers, was gleaned from temperature measurements at various ocean depths up to 750 meters." The team also found that the radiative imbalance was sufficiently small that it was necessary to consider the effect of geothermal heating. Knox believes this is the first time this additional source of heat has been accounted for in such a model.
The team notes that it's impossible to predict when another shift might occur, but they suspect future shifts might be similar to the three observed. Both Douglass and Knox are continuing to analyze various climate-related data to find any new information or correlations that may have so far gone unnoticed.
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About the University of Rochester
The University of Rochester (www.rochester.edu) is one of the nation's leading private universities. Located in Rochester, N.Y., the University gives students exceptional opportunities for interdisciplinary study and close collaboration with faculty through its unique cluster-based curriculum. Its College, School of Arts and Sciences, and Hajim School of Engineering and Applied Sciences are complemented by the Eastman School of Music, Simon School of Business, Warner School of Education, Laboratory for Laser Energetics, Schools of Medicine and Nursing, and the Memorial Art Gallery.
Flux ping.
Douglass further notes that the team found no correlation between the shifts and atmospheric carbon dioxide concentration.
I liked that too.
Or possibly that they are receiving less and emitting the same?
With the low level of sunspot activity I would think that it's possible that that the earth is receiving slightly less than it has at times.
Or possibly that they are receiving less and emitting the same?
With the low level of sunspot activity I would think that it's possible that that the earth is receiving slightly less than it has at times.
That sounds reasonable to me. More important, I think, is that these changes occur short-term and independently of such as carbon dioxide absorption.
Anyone who has seriously studied the data KNOWS that the oceans are moderating the temperature of Earth on several, possibly non-continuous, time scales. There seems to be several “phase shifts” visible in various temperature and radiation data for which the only sensible explanation is oceans absorbing and at some time(s) later releasing heat. The time scales seem to range from daily to millennial. I think a prominent one has a time scale of 6-12 years, and another is a couple centuries long. Until these processes are understood and included in climate models, those models are really garbage.
I'm glad to see that serious work is being done now in this as well as the new ARGOS ocean data network.
It is impressive that these researchers have to include geothermal heat in order get reasonable numbers.
Underwater SUVs?
Who knew?
The ratio of the volumetric heat capacity of water to that of air is approximately 4000, I think. The ratio of the volume of atmosphere to the volume of ocean is around 3. That means that the heat energy contained in the oceans would be approximately 1300 times the heat capacity of the atmosphere.
Only somebody entirely ignorant of physics would attempt to predict the future temperature of the earth's atmosphere without considering whether the ocean is capable of increasing or decreasing the heat in the atmosphere.
For some reason I’m not into finding the exact info, but it is available; I’ve seen it calculated. I think the heating potential of the oceans is something like 400 times that of the atmosphere.
I would accept that. My calculation was about the simplest one could make. The atmosphere probably holds more heat than I assumed because the heat capacity does not decrease with decreasing pressure as much as my simplified calculation assumes.
My exercise was just to show that even the simplest model of the heat capacity of oceans and atmosphere would rule out ignoring the oceans.
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