Equatorial Ionization Anomaly: The Role of Thermospheric Winds and the Effects of the Geomagnetic Field Secular Variation
The vertical plasma drift is the well known driver of the equatorial ionization anomaly (EIA). The latitudinal distribution of ionization in the EIA is determined also by thermospheric meridional wind whose precise role can only be evaluated through the use of theoretical models because it depends not only upon the local configuration of the wind, but is a complex function of its distribution along the entire magnetic field line. Besides, in the Brazilian region, the magnetic field secular variations are fast enough for their effects on the ionosphere to be observed in the time span of the order of a solar cycle. In this work we use the Sheffield University Plasmasphere-Ionosphere Model (SUPIM) to investigate the role of the vertical plasma drift, thermospheric meridional wind and of the magnetic field secular variations in the changing trend of the EIA over the Brazilian region.
KeywordsMeridional Wind Magnetic Equator Drift Model International Geomagnetic Reference Field Vertical Drift
This work was partially supported by CNPq under grant 301643/2009-1.
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