Cool Antarctica May Warm Rapidly This Century, Study Finds

From: Eric Swanson (swanson_at_notspam.net)
Date: 10/22/04 

Date: Fri, 22 Oct 2004 01:31:17 +0000 (UTC)

For Roger, after his post:
Subject: Bush Even Spins Weather Reports!

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GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L18209,
doi:10.1029/2004GL020724, 2004

 Southern Hemisphere climate response to ozone
 changes and greenhouse gas increases

 D. T. Shindell, G. A. Schmidt

 Abstract

 While most of the Earth warmed rapidly during recent decades,
 surface temperatures decreased significantly over most of
 Antarctica. This cooling is consistent with circulation
 changes associated with a shift in the Southern Annular Mode
 (SAM). It has been suggested that both Antarctic ozone depletion
 and increasing greenhouses gases have contributed to these
 trends. We show that a climate model including the stratosphere
 and both composition changes reproduces the vertical structure
 and seasonality of observed trends. We find that the two
 factors have had comparable surface impacts over recent
 decades, though ozone dominates above the middle troposphere.
 Projected impacts of the two factors on circulation over the
 next fifty years oppose one another, resulting in minimal
 trends. In contrast, their effects on surface climate reinforce
 one another, causing a departure from the SAM pattern and a
 turnabout in Antarctic temperatures, which rise more rapidly
 than elsewhere in the Southern Hemisphere.

 Published 25 September 2004.

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-- 
Eric Swanson --- E-mail address: e_swanson(at)skybest.com   :-) 
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