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Eddies and the annular modes of climate variability
Author(s) -
Limpasuvan Varavut,
Hartmann Dennis L.
Publication year - 1999
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 - 10.1029/1999gl010478
Subject(s) - eddy , westerlies , climatology , geology , northern hemisphere , southern hemisphere , troposphere , atmospheric sciences , momentum (technical analysis) , latitude , general circulation model , climate model , climate change , meteorology , oceanography , geodesy , physics , turbulence , finance , economics
The dominant modes of month‐to‐month variation in the troposphere are realistically simulated in a general circulation model whose lower boundary is prescribed with realistic topography and seasonally varying, climatological sea surface temperatures. In both hemispheres, these internal modes describe a nearly zonally symmetric, North‐South shifting of the zonal jets as anomalous westerlies vacillate between high (50°–60°) and low (30°–40°) latitudes. The eddy structures evolve with the jets, and the corresponding eddy momentum forcings support the shifts in jet position. Stationary (synoptic) wave variations mainly account for the total eddy forcings in the Northern (Southern) Hemisphere. Pronounced eddy variations occur over the North Atlantic sector.