Data‐based modeling of the geomagnetosphere with an IMF‐dependent magnetopause

Abstract

The paper presents first results of the data‐based modeling of the geomagnetospheric magnetic field, using the data of Polar, Geotail, Cluster, and Time History of Events and Macroscale Interactions during Substorms satellites, taken during the period 1995–2012 and covering 123 storm events with SYM‐H ≥ −200 nT. The most important innovations in the model are (1) taking into account the interplanetary magnetic field (IMF)‐dependent shape of the model magnetopause, (2) a physically more consistent global deformation of the equatorial current sheet due to the geodipole tilt, (3) symmetric and partial components of the ring current are calculated based on a realistic background magnetic field, instead of a purely dipolar field, used in earlier models, and (4) the validity region on the nightside is extended to ∼40–50 RE. The model field is confined within a magnetopause, based on Lin et al. (2010) empirical model, driven by the dipole tilt angle, solar wind pressure, and IMF Bz. A noteworthy finding is a significant dependence of the magnetotail flux connection across the equatorial plane on the model magnetopause flaring rate, controlled by the southward component of the IMF.