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Isentropic mixing in the Arctic stratosphere during the 1992–1993 and 1993–1994 winters
Author(s) -
Dahlberg Steven P.,
Bowman Kenneth P.
Publication year - 1995
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 - 10.1029/95gl00356
Subject(s) - polar vortex , northern hemisphere , climatology , stratosphere , entrainment (biomusicology) , vortex , atmospheric sciences , arctic , isentropic process , environmental science , the arctic , latitude , meteorology , geology , geography , physics , oceanography , mechanics , geodesy , rhythm , acoustics
Dynamic isolation of the winter Arctic circumpolar vortex during 1992–1993 and 1993–1994 (the second and third northern hemisphere winters of the UARS mission) is studied using quasi‐horizontal isentropic trajectories. Ejection of vortex air and entrainment of mid‐latitude air into the vortex are quantified and compared with climatological values obtained from the analysis of 16 Arctic winters. A number of unusual features of both winters are discussed. The most notable features are the anomalous isolation experienced by the vortex during December 1992 and the unusual degree of isolation and persistence of the vortex during February and March of both years. The 1992–1993 winter season is the most consistently isolated vortex on record. Only during January 1993, when entrainment is large, is this pattern of extreme isolation broken.