Self-consistent inner magnetosphere simulation driven by a global MHD model
Abstract
We present results from a one-way coupling between the kinetic Ring Current Atmosphere Interactions Model with Self-Consistent B field (RAM-SCB) and the Space Weather Modeling Framework (SWMF). RAM-SCB obtains plasma distribution and magnetic field at model boundaries from the Block Adaptive Tree Solar Wind Roe Upwind Scheme (BATS-R-US) magnetohydrodynamics (MHD) model and convection potentials from the Ridley Ionosphere Model within SWMF. We simulate the large geomagnetic storm of 31 August 2005 (minimum SYM-H of -116 nT). Comparing SWMF output with Los Alamos National Laboratory geostationary satellite data, we find SWMF plasma to be too cold and dense if assumed to consist only of protons; this problem is alleviated if heavier ions are considered. With SWMF inputs, we find that RAM-SCB reproduces well storm time magnetosphere features: ring current morphology, dusk side peak, pitch angle anisotropy, and total energy. The RAM-SCB ring current and Dst are stronger than the SWMF ones and reproduce observations much better. The calculated field-aligned currents (FAC) compare reasonably well with 2 h averaged pictures from Iridium satellite data. As the ring current peak rotates duskward in the storm main phase, the region 2 FACs rotate toward noon, a feature also seen in observations. Finally, the RAM-SCB magnetic field outperforms both the dipole and the BATS-R-US field at Cluster and Polar spacecraft locations. This study shows the importance of a kinetic self-consistent approach and the sensitive dependence of the storm time inner magnetosphere on plasma sheet conditions and the cross polar cap potential. The study showcases the RAM-SCB capability as an inner magnetosphere module coupled with a global MHD model.
- Publication:
-
Journal of Geophysical Research (Space Physics)
- Pub Date:
- December 2010
- DOI:
- 10.1029/2010JA015915
- Bibcode:
- 2010JGRA..11512228Z
- Keywords:
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- Magnetospheric Physics: Ring current;
- Magnetospheric Physics: Magnetospheric configuration and dynamics;
- Magnetospheric Physics: Energetic particles: trapped;
- Magnetospheric Physics: Magnetic storms and substorms (7954);
- Magnetospheric Physics: Numerical modeling;
- numerical modeling;
- ring current;
- inner magnetosphere;
- self-consistent simulation;
- magnetic fields