Duskside F-region dynamo currents: its relationship with prereversal enhancement of vertical plasma drift

• Main Authors: J. Park, H. Lühr, B. G. Fejer, K. W. Min
• Format: Article
• Language: English
• Published: Copernicus Publications 2010-11-01
• Series: Annales Geophysicae
• Online Access: https://www.ann-geophys.net/28/2097/2010/angeo-28-2097-2010.pdf

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.