Convection electric field in the near-Earth tail during the super magnetic storm of November 20-21, 2003

Abstract

[1] We examine the electric field observations made by the Geotail spacecraft in the magnetotail during the intense magnetic storm of November 20-21, 2003. During this storm, Geotail traversed the magnetotail at R ∼ 9-12 Re from dusk to dawn through the midnight sector at ∼17 UT on November 20 and observed the convection electric field in the near-Earth plasma sheet for the main phase and early recovery phase. While the electric field in the plasma sheet during the storm interval shows highly turbulent characteristics in a wide range of local time, the average intensity of the duskward electric field is not so different in magnitude from those observed during other small to moderate level storms. A comparison with those calculated using the empirical models reveals that the independent behavior of the tail convection intensity with regard to the storm driver intensity still holds for an intense storm case. These results give a further support to the hypothesis suggested by our previous study that the tail convection supplies the ring current particles rather constantly regardless of the solar wind condition. Copyright 2006 by the American Geophysical Union.