Posted on 09/29/2006 3:19:10 PM PDT by blam
Mystery of the Missing Heat: Upper ocean has cooled slightly in recent years, despite warming climate
Sid Perkins
Between 2003 and 2005, the top layers of the world's oceans cooled slightly, but scientists aren't sure where the heat went.
According to climate data gathered worldwide, 2003, 2004, and 2005 are three of the five warmest years since reliable record keeping of global air temperatures began more than a century ago. However, oceanographic surveys suggest that on average, the upper 750 meters of the world's ice-free oceans cooled about 0.03°C during that 3-year period.
This cooling reverses an oceanic-warming trend observed since the 1950s, oceanographer John M. Lyman and his colleagues report in the Sept. 28 Geophysical Research Letters. Between 1993 and 2003, the average temperature of the upper layers of the icefree ocean rose about 0.09°C, they note.
The newly documented cooling occurred throughout the top 750 m of ocean and seems to have extended to deeper waters as well, says study coauthor Josh K. Willis, an oceanographer now at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Data used in the new analysis were gathered by buoys tethered in deep water, instruments towed by or dropped from ships, and an armada of robotic probes, says Lyman, who's at the National Oceanographic and Atmospheric Administration (NOAA) laboratory in Seattle.
While the top layers of the ocean have cooled slightly overall, some limited areas have warmed, says coauthor Gregory C. Johnson, also of NOAA in Seattle. The cooling trend, as well as its patchiness, probably results from variations in climate cycles such as the Pacific Decadal Oscillation, he notes.
"Even within a long-term warming trend, you can have short-term drops in [ocean] temperature due to year-to-year variability," says Lyman.
Scientists are working to identify where the heat went. One possibility: It may have moved to the deepest layers of the ocean. The cooling of surface waters would cause them to contract, triggering a small drop in sea level, says Willis. But satellite data suggest that sea level is still rising. So, the missing heat may have gone deep, causing waters there to expand and prevent a decline in sea level. However, "it's hard to envision a way to put that much heat down deep so quickly," says Willis.
In another scenario under consideration, the missing heat may have radiated into space. However, satellite observations don't support that notion, says Bruce A. Wielicki, a physicist at NASA's Langley Research Center in Hampton, Va. Yet another possibility is that the heat warmed some of the waters in polar regions and promoted melting of the ice cover there, he notes.
"We have a few more pieces to unravel" about where the heat has gone, comments Sarah T. Gille, an oceanographer at Scripps Institution of Oceanography in La Jolla, Calif. "It's a real conundrum."
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BUMP!
Hmmmmm, interesting. All of that stuff combined could have some effect. But if we had a major ice age similar to the one that sent glaciers all the way into present-day America and carved out the Great Lakes, somehow I think our efforts would be overwhelmed by the lack of solar energy reaching earth. But it all depends on how big the greenhouse effect really is from CFC's, CO2, etc. We're still building our knowledge of the greenhouse effect and nobody knows for sure whether these gases really generate a greenhouse effect and how strong that effect is.
I can tell ya this.
The amount of energy currently coming to the earth from the sun is so much bigger than anything we can generate...and the energy that will be lost when the earth transitions to an oval orbital pattern (due to Milankovitch Forcing) will be so large that we would LOVE to have greenhouse gasses to keep some heat in...
The plain fact is, the earth is REALLY REALLY big, and we are REALLY REALLY small and we cannot really affect things on the scale that Al Gore imagines.
Actually, can we be sure that increased melting of our ice caps doesn't cool the surrounding water somewhat?
You might find this site interesting
Antarctic Ice Increasing AND Decreasing
http://www.ecoenquirer.com/antarctic-ice.htm
Seemingly contradictory research results, such as recent reports of both decreasing and increasing Antarctic ice, can be explained with a new metaphysical theory.
Ya know, these guys are putting their jobs on the line to publish this stuff.
yitbos
There are a number of sources on Milankovitch Forcing from Wikipedia to N.O.A.A.
The basic premise is that the earth's orbit is not a perfect circle, nor a constant ellipse, but rather varies from circular to elliptical over time in a periodic fashion.
The variation is caused by the variation in gravitational forces upon the earth by the other planets, which have their own orbits which also vary. As they move around the sun at different rates, sometimes they are closer to each other (and their gravitational force sums to pull the earth slightly) and other times they are on opposite sides of the sun from each other (at which point their gravitational force subtracts from each other).
There are actually a LOT of different sources of variation and the records show very slow changes (120Kyr - Milankovitch) to as small as 11 yrs due to solar flare activity.
Have fun.
It said the IPCC report also "warns that carbon dioxide emissions have risen during the past five years by three percent, well above the 0.4 percent a year average of the previous two decades."
Interestingly global land and atmospheric temperatures have not increased in, the last eight years.
Ocean temperatures have actually fallen for the last three years.
Bottomline, direct radiation effects of CO2 at the surface is 0.2oC or each doubling of CO2 concentration in the atmosphere and the Global Warming hype depends on hypothetical feedback processes implemented in models but eludes empirical confirmation in the real world.
"the direct radiative effects of doubled CO2 can cause a maximum surface warming [at the equator] of about 0.2 K, and hence roughly 90% of the 2.0-2.5K surface warming obtained by the GCM is caused by atmospheric feedback processes described above."
--- "Increased Atmospheric CO2: Zonal and Seasonal Estimates of the Effect on the Radiation Energy Balance and Surface Temperature" (V. Ramanathan and M. S. Lian), J. Geophys. Res., Vol. 84, p. 4949, 1979.
There are a number of sources on Milankovitch Forcing from Wikipedia to N.O.A.A.
And recent work that investigates the problematic nature of Milankovitch's cycles offer an alternative source of the 100k cycle that fits much better than eccentricity.
Refer:
Ice Ages & Astronomical Causes
Brief Introduction to the History of Climate
by Richard A. MullerSpectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity
Richard A. Muller* and Gordon J. MacDonald
I thought everyone already knew that.
Interesting reading...I started on it and bookmarked it.
Note: Neither source suggests that human activity is responsible for the huge shifts in global temperature that have occurred over the eons.
I don't buy it. Cold water is denser than warm water, so it would have been the cold water to move down there.
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