Premium
A Modeling Study of the Responses of Mesosphere and Lower Thermosphere Winds to Geomagnetic Storms at Middle Latitudes
Author(s) -
Li Jingyuan,
Wang Wenbin,
Lu Jianyong,
Yue Jia,
Burns Alan G.,
Yuan Tao,
Chen Xuetao,
Dong Wenjun
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja026533
Subject(s) - thermosphere , atmospheric sciences , mesosphere , advection , geomagnetic storm , storm , latitude , atmospheric tide , middle latitudes , earth's magnetic field , prevailing winds , ionosphere , geology , climatology , environmental science , geophysics , physics , geodesy , stratosphere , oceanography , quantum mechanics , magnetic field , thermodynamics
Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model (TIMEGCM) simulations are diagnostically analyzed to investigate the causes of mesosphere and lower thermosphere (MLT) wind changes at middle latitudes during the 17 April 2002 storm. In the early phase of the storm, middle‐latitude upper thermospheric wind changes are greater and occur earlier than MLT wind changes. The horizontal wind changes cause downward vertical wind changes, which are transmitted to the MLT region. Adiabatic heating and heat advection associated with downward vertical winds cause MLT temperature increases. The pressure gradient produced by these temperature changes and the Coriolis force then drive strong equatorward meridional wind changes at night, which expand toward lower latitudes. Momentum advection is minor. As the storm evolves, the enhanced MLT temperatures produce upward vertical winds. These upward winds then lead to a decreased temperature, which alters the MLT horizontal wind pattern and causes poleward wind disturbances at higher latitudes.