Tuesday, May 25, 2010

General Ocean Warming Confirmed

There is nothing more wonderful in science than data that is creditable.  This confirms that over the past two decades or so, that the ocean is storing more heat that breakeven.  It does not tell us why and it could have more to do with a switch over in the global current system than say the sun itself which is not obviously warmer.

Of course we merely may not be able to measure the obvious.  All I know for sure is that any given hypothesis has its champions and detractors and no consensus exists.

Obviously if there is simply more heat been stored in the ocean perhaps reflecting a slower movement rate for some obscure reason or perhaps a lower volume rate, then an obvious consequence is a larger injection of warmer water into the Arctic and we have at least clarified what is going on there.

Since the bronze age found surface temperatures in the Atlantic as much as two degrees warmer we also know that this process is unlikely to be temporary.

So why is the ocean warming?  Or perhaps more accurately, why is more sunlight been absorbed than what we have previously understood or have we have we simply missed important information?

Perhaps the Antarctic is presently not consuming as much heat as in the past.  That is the mechanism that I think able to make the necessary shifts we have been seeing.  If the Antarctic simply does not draw warm surface water in or alternately not push a lot of cold water out then we have the necessary influence that could shift over the centuries and act like a switch by abruptly dumping a lot of deep cold water into the rest of the ocean once every thousand years or so.

Yet present warming appears to be reflecting a strengthening that is superior to what has preceded it.  Since we know that a two degree is in fact possible in the north Atlantic this is evidence conforming to a restoration of the warm climate of the known warm eras.

Integrating it all is still some ways off.

New Study Finds Ocean Warmed Significantly Since 1993

The international science team analyzed nine different estimates of heat content in the upper ocean, based on ocean temperature data from a global array of more than 3,200 Argo free-floating profiling floats and longer data records from expendable bathythermographs dropped from ships. Image credit: International Argo Project

by Staff Writers

Washington DC (SPX) May 21, 2010

The upper layer of Earth's ocean has warmed since 1993, indicating a strong climatechange signal, according to a new international study co-authored by oceanographer Josh Willis of NASA's Jet Propulsion Laboratory, Pasadena, Calif. The energy stored is enough to power nearly 500 100-watt light bulbs for each of the roughly 6.7 billion people on the planet.

"We are seeing the global ocean store more heat than it gives off," said John Lyman, an oceanographer at the National Oceanic and Atmospheric Administration's Joint Institute for Marine and Atmospheric Research, who led the study that analyzed nine different estimates of heat content in the upper ocean from 1993 to 2008.

The team combined the estimates to assess the size and certainty of growing heat storage in the ocean. Their findings will be published in the May 20 edition of the journal Nature. The scientists are from NASA, NOAA, the Met Office Hadley Centre in the United Kingdom, the University of Hamburg in Germany and the Meteorological Research Institute in Japan.

"The ocean is the biggest reservoir for heat in the climate system," said Willis. "So as the planet warms, we're finding that 80 to 90 percent of the increased heat ends up in the ocean."

A warming ocean is a direct cause of global sea level rise, since seawater expands and takes up more space as it heats up. The scientists say that this expansion accounts for about one-third to one-half of global sea level rise.

Combining multiple estimates of heat in the upper ocean - from the surface to about 610 meters (2,000 feet) down - the team found a strong multi-year warming trend throughout the world's ocean.

According to measurements by an array of autonomous free-floating ocean floats called Argo, as well as by earlier devices called expendable bathythermographs, or XBTs, that were dropped from ships to obtain temperature data, ocean heat content has increased over the last 16 years.

The team notes that there are still some uncertainties and some biases.

"The XBT data give us vital information about past changes in the ocean, but they are not as accurate as the more recent Argo data," said Gregory Johnson, an oceanographer at NOAA's Pacific Marine Environmental Laboratory. "However, our analysis of these data gives us confidence that on average, the ocean has warmed over the past decade and a half, signaling a climate imbalance."

Data from the array of Argo floats - deployed by NOAA and other U.S. and international partners - greatly reduce the uncertainties in estimates of ocean heat content over the past several years, the team said. There are now more than 3,200 Argo floats distributed throughout the world's ocean sending back information via satellite on temperature, salinity, currents and other ocean properties.

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