Papers on Magnetospheric Physics
Global simulation of the Geospace Environment Modeling substorm challenge event
Article first published online: 20 SEP 2012
Copyright 2001 by the American Geophysical Union.
Journal of Geophysical Research: Space Physics (1978–2012)
Volume 106, Issue A1, pages 381–395, 1 January 2001
How to Cite
2001), Global simulation of the Geospace Environment Modeling substorm challenge event, J. Geophys. Res., 106(A1), 381–395, doi:10.1029/2000JA000605., , , , , , , , , and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 4 MAY 2000
- Manuscript Received: 9 FEB 2000
We use a global model of Earth's magnetosphere and ionosphere to simulate the Geospace Environment Modeling (GEM) substorm challenge event of November 24, 1996. We compare our results to International Monitor for Auroral Geomagnetic Effects (IMAGE) ground magnetometer data, assimilative mapping of ionospheric electrodynamics (AMIE) polar cap potential and field aligned current patterns, Polar Visible Imaging System (VIS) estimates of the polar cap magnetic flux, GOES 8 geosynchronous magnetometer data, IMP 8 magnetometer data, and Geotail plasma and magnetic field data. We find generally good agreement between the simulation and the data. The modeled evolution of this substorm generally follows the phenomenological near-Earth neutral line model. However, reconnection in the tail is very localized, which makes establishing a causal relation between tail dynamics and auroral dynamics difficult, if not impossible. We also find that the model results critically depend on the parameterization of auroral Hall and Pedersen conductances and anomalous resistivity in the magnetosphere. For many combinations of parameters that enter these parameterizations, no substorm develops in the model, but instead the magnetosphere enters a steady convection mode. The main deviation of the model from the data is excessive convection, which leads to a strong, driven westward electrojet in the growth phase, only partial tail loading, and a reduced recovery phase. Possible remedies are a better model for auroral conductances, an improved anomalous resistivity model, and a more realistic treatment of the ring current.