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[school-discuss] global warming ---> it's a good bit cooler than the government models assumed

August 28, 2002


Atmospheric measurements made at Earth's geographic poles provide a convenient 
way of validating and calibrating global circulation models. Such 
measurements also might provide some of the first conclusive evidence of 
global change in the middle and upper atmospheres. But new data shows that 
the current models are wrong: Temperatures over the South Pole are much 
colder in winter than scientists had anticipated.

As reported in the Aug. 28 issue of Geophysical Research Letters, scientists 
have found that temperatures during mid-winter in the stratopause and 
mesopause regions at the South Pole are about 40-50 degrees Fahrenheit colder 
than model predictions. 


"With the reduced down-welling, the predicted mesopause temperature near 60 
miles altitude decreased from about minus 120 degrees Fahrenheit to about 
minus 140 degrees Fahrenheit, in better agreement with our measurements for 
mid-winter conditions," Gardner said. "In the stratopause region, the 
predicted temperature decreased from about 35 degrees Fahrenheit to about 12 
degrees Fahrenheit, also in better agreement with our measurements."

The recent measurements establish a baseline for polar temperatures, which can 
then be compared against future changes as greenhouse gases continue to 
accumulate, Gardner said. "The measurements also show that we have a flaw in 
some of our global atmospheric circulation models. Now we can go back and 
improve those models to better predict the temperatures in the middle and 
upper atmospheres throughout both hemispheres."

The National Science Foundation funded the work.



Jim Kloeppel,

This text derived from http://www.news.uiuc.edu/scitips/02/0828southpole.html