Duskside F-region dynamo currents: its relationship with prereversal enhancement of vertical plasma drift
From magnetic field observations by CHAMP we estimate F-region dynamo current densities near the sunset terminator during solar maximum years from 2001 to 2002. The dynamo currents are compared with the pre-reversal enhancement (PRE) of vertical plasma drift as observed by ROCSAT-1. The seasonal...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2010-11-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/28/2097/2010/angeo-28-2097-2010.pdf |
| Summary: | From magnetic field observations by CHAMP we estimate F-region dynamo current
densities near the sunset terminator during solar maximum years from 2001 to
2002. The dynamo currents are compared with the pre-reversal enhancement
(PRE) of vertical plasma drift as observed by ROCSAT-1. The
seasonal-longitudinal variation of PRE can be largely related to the F-region
dynamo current density, with the correlation coefficient reaching 0.74. The
correlation can be further improved if we consider a zonal gradient of the
E-region Pedersen conductivity, which also depends on season and longitude.
It is widely accepted that the F-region dynamo drives PRE near sunset. For
the first time, our observations provide confirmation for the close
relationship between the F-region dynamo current density and PRE. |
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| ISSN: | 0992-7689 1432-0576 |