http://www.agu.org/pubs/crossref/200...GL018584.shtml
GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L02301, doi:10.1029/2003GL018584, 2004
Does the recent freshening trend in the North Atlantic indicate a weakening thermohaline
circulation?
Peili Wu, Richard Wood, and Peter Stott
Met Office, Hadley Centre for Climate Prediction and Research,United Kingdom

Abstract
[1] It is widely expected that the thermohaline circulation of the ocean will slow down as
greenhouse gas concentration in the atmosphere increases. This is partly due to an intensified
hydrological cycle in a warmer climate. Is the recent observed freshening trend in the North
Atlantic an indication of what has been expected? We report a similar freshening trend reproduced in
an ensemble of four coupled model simulations with all major historical external (natural and
anthropogenic) forcings. The modelled freshening trend originates from the Arctic Ocean where sea
ice decrease and river runoffs increase with the same trend. Instead of weakening, we find an upward
trend in the North Atlantic meridional overturning circulation.


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david
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