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On the temporal character and regionality of the Arctic Oscillation
Author(s) -
Overland James E.,
Adams Jennifer Miletta
Publication year - 2001
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 - 10.1029/2000gl011739
Subject(s) - arctic oscillation , climatology , north atlantic oscillation , arctic , zonal and meridional , the arctic , geology , oscillation (cell signaling) , pacific decadal oscillation , oceanography , sea surface temperature , biology , genetics
Decadal differences between the 1990s and 1980s in winter (JFM) sea‐level pressure and 300 mb zonal winds have an Arctic‐centered character with nearly equal contributions from the Atlantic and Pacific sectors. In contrast, the differences between positive and negative Arctic Oscillation (AO) composites defined from monthly values of Principal Components from the same period have similar magnitudes in the Pacific and Arctic, but have an additional large North Atlantic Oscillation (NAO) signature in the Atlantic sector. Thus Arctic changes on decadal scales are more symmetric with the pole than suggested by the standard AO index definition. Change point analysis of the AO shows that a shift in value near 1989 is an alternate hypothesis to a linear trend. Analysis of zonal and meridional winds by longitudinal sectors shows the importance of the standing wave pattern in interpreting the AO, which supplements the view of the AO as a simple zonal average (annular) mode.