HR: 15:10h
AN: SM23C-06    [Abstracts]
TI: Using DOUBLE STAR and CLUSTER Synoptic Observations to Test Global MHD Simulations of the Large-scale Topology of the Dayside Merging Region
AU: * Berchem, J
EM: jberchem@igpp.ucla.edu
AF: IGPP, UCLA, Los Angeles, CA 90095-1567 United States
AU: Marchaudon, A
SM23C-06 AF: Mullard SSL, University College London, Surrey, RH5 6NT United Kingdom
AU: Bosqued, J
SM23C-06 AF: CNRS, CESR, Toulouse, 31000 France
AU: Escoubet, C P
SM23C-06 AF: ESA, ESTEC, Noordwijk, 2200 AG Netherlands
AU: Dunlop, M
SM23C-06 AF: Rutherford Appleton Laboratory, Didcot, Oxon, OX11 0QX United Kingdom
AU: Owen, C J
SM23C-06 AF: Mullard SSL, University College London, Surrey, RH5 6NT United Kingdom
AU: Reme, H
SM23C-06 AF: CNRS, CESR, Toulouse, 31000 France
AU: Balogh, A
SM23C-06 AF: The Blackett Laboratory, Imperial College, London, SW7 2BZ United Kingdom
AU: Carr, C
SM23C-06 AF: The Blackett Laboratory, Imperial College, London, SW7 2BZ United Kingdom
AU: Fazakerley, A N
SM23C-06 AF: Mullard SSL, University College London, Surrey, RH5 6NT United Kingdom
AU: Cao, J B
SM23C-06 AF: Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, 100080 China
AB: Synoptic measurements from the DOUBLE STAR and CLUSTER spacecraft offer a unique opportunity to evaluate global models in simulating the complex topology and dynamics of the dayside merging region. We compare observations from the DOUBLE STAR TC-1 and CLUSTER spacecraft on May 8, 2004 with the predictions from a three-dimensional magnetohydrodynamic (MHD) simulation that uses plasma and magnetic field parameters measured upstream of the bow shock by the WIND spacecraft. Results from the global simulation are consistent with the large-scale features observed by CLUSTER and TC-1. We discuss topological changes and plasma flows at the dayside magnetospheric boundary inferred from the simulation results. The simulation shows that the DOUBLE STAR spacecraft passed through the dawn side merging region as the IMF rotated. In particular, the simulation indicates that at times TC-1 was very close to the merging region. In addition, we found that the bifurcation of the merging region in the simulation results is consistent with predictions by the antiparallel merging model. However, because of the draping of the magnetosheath field lines over the magnetopause, the positions and shape of the merging region differ significantly from those predicted by the model.
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2724 Magnetopause and boundary layers
DE: 2740 Magnetospheric configuration and dynamics
DE: 2753 Numerical modeling
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005