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Interhemispheric Asymmetry of the Sunward Plasma Flows for Strongly Dominant IMF B Z > 0
Author(s) -
Yakymenko K. N.,
Koustov A. V.,
Fiori R. A. D.
Publication year - 2018
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2017ja024644
Subject(s) - noon , northern hemisphere , southern hemisphere , interplanetary magnetic field , geology , midnight , latitude , polar , ionosphere , convection , physics , atmospheric sciences , geophysics , geodesy , magnetic field , climatology , solar wind , meteorology , astronomy , quantum mechanics
Super Dual Auroral Radar Network (SuperDARN) convection maps obtained simultaneously in both hemispheres are averaged to infer polar cap ionospheric flow patterns under strongly dominant positive interplanetary magnetic field (IMF) B z component. The data set consisted of winter observations in the Northern Hemisphere simultaneously with summer observations in the Southern Hemisphere. Long‐lasting high‐latitude dayside reverse convection cells are shown to have faster sunward flows at near‐magnetic noon hours in the summer/Southern Hemisphere. Sunward flows typically deviate from the midnight‐noon meridian toward 10–11 h of magnetic local time in the summer/Southern Hemisphere and are more aligned with the midnight‐noon meridian in the winter/Northern Hemisphere. Flow deviations in the winter/Northern Hemisphere can be both toward prenoon and postnoon hours, and there is no clear relationship between flow deviation and the IMF B y component. No strong preference for the sunward flow occurrence depending on the IMF B x polarity was found. In addition, the rate of the sunward flow speed increase in response to an increase in driving conditions was found to be comparable for the IMF B x > 0 and B x < 0 .