Friday, August 14, 2009

Changes in net flow of ocean heat correlate with past climate anomalies

Science Daily: 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."…

Image by NASA

No comments: