Physics
Scientific paper
Dec 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006agufmsm33d..05c&link_type=abstract
American Geophysical Union, Fall Meeting 2006, abstract #SM33D-05
Physics
2730 Magnetosphere: Inner, 2753 Numerical Modeling, 2778 Ring Current, 2784 Solar Wind/Magnetosphere Interactions, 2788 Magnetic Storms And Substorms (7954)
Scientific paper
The plasmasheet source for the stormtime ring current depends significantly on the interplanetary conditions during the preceding quiet period. We have investigated how this dependence affects the local-time asymmetries in storm-time ring current development by applying realistic plasmasheet boundary conditions based on averages of GEOTAIL data to a magnetically self-consistent ring-current simulation model. By statistical analysis of GEOTAIL data, Wang et al. [this meeting] have found two interesting trends: (1) For strongly northward IMF (2 nT < IMF B_z < 8 nT), high solar-wind density (> 6.5 cm-3), and lower solar-wind speed (< 400 km/s), the overall plasmasheet ion density is the highest among the northward IMF conditions considered, and there is a strong dawn-dusk asymmetry at radial distances r > 8 R_E with high ion densities and low ion temperatures in the post-midnight quadrant of the plasma sheet. (2) For weakly northward IMF (0 < IMF B_z < 2 nT), high solar-wind speed (> 400 km/s), and lower solar-wind density (< 6.5 cm-3), the overall plasmasheet ion density is the lowest and its temperature is highest in the pre-midnight sector among all the northward IMF conditions considered, and there is no strong density enhancement in the post-midnight quadrant of the plasma sheet at r > 8 R_E, such as is seen on average under condition (1). From simple particle-transport considerations, it is expected that condition (1), under which there is (on average) a dense population of low-energy ions in the post-midnight quadrant, may lead to relative enhancement of the ring-current plasma pressure in the post-midnight quadrant. In contrast, condition (2), in which there is (on average) a dense population of high-energy particles in the pre-midnight quadrant of the plasma sheet, may lead to enhancement of the ring-current plasma pressure in the pre-midnight quadrant rather than elsewhere. We test these hypotheses by carrying out magnetically self-consistent simulations of the ring current with appropriate boundary conditions, corresponding to the two different solar-wind conditions and for boundary conditions made time-dependent in accordance with actual solar-wind conditions during a particular geomagnetic storm. In our ring current simulations the magnetic field is in force balance with the plasma in the equatorial plane. The electric field includes corotation, quiescent Stern-Volland convection, and storm-associated enhancements in a less well-shielded convection electric field. The boundary conditions for the ring current model are applied at geosynchronous altitude in this study, which we obtain by mapping the GEOTAIL data to geosynchronous altitude using a modified Magnetospheric Specification Model.
Chen Margaret W.
Lyons Larry R.
Schulz Michael
Wang Chenjie
No associations
LandOfFree
Solar Wind Influence on MLT Dependence of Plasmasheet Conditions and Implications for Ring Current Modeling does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Solar Wind Influence on MLT Dependence of Plasmasheet Conditions and Implications for Ring Current Modeling, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solar Wind Influence on MLT Dependence of Plasmasheet Conditions and Implications for Ring Current Modeling will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-973404