Rusted Sky

JPL.NASA.GOV: News Releases

NASA Sees Arctic Ocean Circulation Do an About-Face
November 13, 2007
PASADENA, Calif. – A team of NASA and university scientists has detected an ongoing reversal in Arctic Ocean circulation triggered by atmospheric circulation changes that vary on decade-long time scales. The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming.

The team, led by James Morison of the University of Washington's Polar Science Center Applied Physics Laboratory, Seattle, used data from an Earth-observing satellite and from deep-sea pressure gauges to monitor Arctic Ocean circulation from 2002 to 2006.

They measured changes in the weight of columns of Arctic Ocean water, from the surface to the ocean bottom. That weight is influenced by factors such as the height of the ocean's surface, and its salinity. A saltier ocean is heavier and circulates differently than one with less salt.

As I've said before - we keep assuming that there's some sort of 'normal' state that we should try to maintain. The question I've got about that is - who gets to define normal? Are we looking at temps during the Little Ice Age? Or the Medieval Climate Optimum? Maybe the 1930s - THAT was a fun time.

The Earth has cycles that we're only beginning to understand. The big trick, near as I can tell it, is to figure out what we've got to be READY for.

Not try to determine some artificial set-point on the Earth's thermostat.

J.