Premium
Simulated Sudden Stratospheric Warming; Synoptic Evolution
Author(s) -
Blackshear W. T.,
Grose W. L.,
Turner R. E.
Publication year - 1987
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.49711347707
Subject(s) - anticyclone , climatology , sudden stratospheric warming , advection , stratosphere , environmental science , atmospheric sciences , westerlies , global warming , atmospheric circulation , cyclone (programming language) , geology , polar vortex , climate change , oceanography , physics , field programmable gate array , computer science , computer hardware , thermodynamics
An analysis is presented of a sudden stratospheric warming event which occurred spontaneously during a general circulation model simulation of the global atmospheric circulation. Two separate warming pulses exhibit the same dynamical evolution with a ‘cycle’ of about two weeks. Two distinct phases of the warming cycle are apparent: (1) the generation of an intense localized warm cell in conjunction with significant adiabatic heating associated with cross‐isobar flow which has been induced by vertically propagating long wave disturbances; and (2) the northward transport of that warm cell via advection by the essentially geostrophic windfield corresponding to an intense, offset polar cyclone, in conjunction with a strong Aleutian anticyclone. During the first warming pulse in January, a moderate Aleutian anticyclone was in place prior to the warming cycle and was intensified by interaction with an eastward travelling anticyclone induced by the differential advection of the warm cell. the second warming pulse occurred in early February with a strong Aleutian anticyclone already established. In contrast to the January event, the warming in February culminated with reversal of the zonal westerlies to easterlies over a significant depth of the stratosphere.