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Geomagnetic activity signatures in wintertime stratosphere wind, temperature, and wave response
Author(s) -
Seppälä A.,
Lu H.,
Clilverd M. A.,
Rodger C. J.
Publication year - 2013
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/jgrd.50236
Subject(s) - stratosphere , polar vortex , earth's magnetic field , atmospheric sciences , northern hemisphere , climatology , quasi biennial oscillation , geology , sudden stratospheric warming , environmental science , physics , magnetic field , quantum mechanics
We analyzed ERA‐40 and ERA Interim meteorological re‐analysis data for signatures of geomagnetic activity in zonal mean zonal wind, temperature, and Eliassen‐Palm flux in the Northern Hemisphere extended winter (November–March). We found that for high geomagnetic activity levels, the stratospheric polar vortex becomes stronger in late winter, with more planetary waves being refracted equatorward. The statistically significant signals first appear in December and continue until March, with poleward propagation of the signals with time, even though some uncertainty remains due to the limited amount of data available ( ∼ 50 years). Our results also indicated that the geomagnetic effect on planetary wave propagation has a tendency to take place when the stratosphere background flow is relatively stable or when the polar vortex is stronger and less disturbed in early winter. These conditions typically occur during high solar irradiance cycle conditions or westerly quasi‐biennial oscillation conditions.