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Solar flare impacts on ionospheric electrodyamics
Author(s) -
Qian Liying,
Burns Alan G.,
Solomon Stanley C.,
Chamberlin Phillip C.
Publication year - 2012
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 - 10.1029/2012gl051102
Subject(s) - tec , ionosphere , solar flare , physics , f region , electron density , atmospheric sciences , flare , equator , magnetic dip , zenith , total electron content , solar maximum , geophysics , electron , astrophysics , solar cycle , magnetic field , astronomy , solar wind , latitude , optics , quantum mechanics
The sudden increase of X‐ray and extreme ultra‐violet irradiance during flares increases the density of the ionosphere through enhanced photoionization. In this paper, we use model simulations to investigate possible additional contributions from electrodynamics, finding that the vertical E × B drift in the magnetic equatorial region plays a significant role in the ionosphere response to solar flares. During the initial stage of flares, upward E × B drifts weaken in the magnetic equatorial region, causing a weakened equatorial fountain effect, which in turn causes lowering of the peak height of the F 2 region and depletion of the peak electron density of the F 2 region. In this initial stage, total electron content (TEC) enhancement is predominantly determined by solar zenith angle control of photoionization. As flares decay, upward E × B drifts are enhanced in the magnetic equatorial region, causing increases of the peak height and density of the F 2 region. This process lasts for several hours, causing a prolonged F 2 ‐region disturbance and TEC enhancement in the magnetic equator region in the aftermath of flares. During this stage, the global morphology of the TEC enhancement becomes predominantly determined by these perturbations to the electrodynamics of the ionosphere.