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On the atmospheric response experiment to a Blue Arctic Ocean
Author(s) -
Nakamura Tetsu,
Yamazaki Koji,
Honda Meiji,
Ukita Jinro,
Jaiser Ralf,
Handorf Dörthe,
Dethloff Klaus
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl070526
Subject(s) - environmental science , the arctic , arctic , climatology , oceanography , atmospheric sciences , meteorology , geology , geography
We demonstrated atmospheric responses to a reduction in Arctic sea ice via simulations in which Arctic sea ice decreased stepwise from the present‐day range to an ice‐free range. In all cases, the tropospheric response exhibited a negative Arctic Oscillation (AO)‐like pattern. An intensification of the climatological planetary‐scale wave due to the present‐day sea ice reduction on the Atlantic side of the Arctic Ocean induced stratospheric polar vortex weakening and the subsequent negative AO. Conversely, strong Arctic warming due to ice‐free conditions across the entire Arctic Ocean induced a weakening of the tropospheric westerlies corresponding to a negative AO without troposphere‐stratosphere coupling, for which the planetary‐scale wave response to a surface heat source extending to the Pacific side of the Arctic Ocean was responsible. Because the resultant negative AO‐like response was accompanied by secondary circulation in the meridional plane, atmospheric heat transport into the Arctic increased, accelerating the Arctic amplification.