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Electrodynamical Coupling of the Geospace System During Solar Flares
Author(s) -
Liu Jing,
Qian Liying,
Maute Astrid,
Wang Wenbin,
Richmond Arthur D.,
Chen Junjie,
Lei Jiuhou,
Zhang Qinghe,
Xing Zanyang
Publication year - 2021
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja028569
Subject(s) - ionosphere , dynamo , flare , solar flare , physics , solar wind , atmospheric sciences , daytime , geophysics , astrophysics , plasma , magnetic field , quantum mechanics
Reduced daytime upward E×B drifts and weakened fountain effects in equatorial ionosphere have been frequently observed during the initial stage of solar flares. The cause of this phenomenon, however, remains unresolved. The latest state‐of‐art whole geospace model provides an unprecedented opportunity to explore the origin of this response. We show that both prompt penetration electric fields (PPEFs) and internal changes in the wind dynamo process are responsible for the reduced upward ion drifts. Solar‐flare‐induced PPEFs are caused by a reduced high‐latitude potential as a result of flare‐enhanced ionospheric conductances which are distinct from traditional PPEFs that respond to changes in solar wind conditions or magnetosphere dynamics. The neutral wind dynamo source is mainly a reduction in the background low‐latitude eastward electric field. This reduction occurs to maintain current continuity in response to the flare enhancement of low‐latitude Cowling conductance that is relatively greater than the enhancement of the dynamo current source.