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Global MHD Simulations of Dayside Magnetopause Dynamics. THEMIS Event: May 20, 2008 20:30 – 22:30. M. M. Kuznetsova, D. G. Sibeck , M. Hesse , L. Rastaetter , T. Gombosi. http:// ccmc.gsfc.nasa.gov. NASA Goddard Space Flight Center. Global MHD Simulation Model.
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Global MHD Simulations of Dayside Magnetopause Dynamics. THEMIS Event: May 20, 2008 20:30 – 22:30 M. M. Kuznetsova, D. G. Sibeck, M. Hesse, L. Rastaetter, T. Gombosi http://ccmc.gsfc.nasa.gov NASA Goddard Space Flight Center
Global MHD Simulation Model BATS-R-US (CSEM, University of Michigan)uses an adaptive grid composed of rectangular blocks arranged in varying degrees of spatial refinement levels. Resolution at Dayside Magnetopause Including Flanks: 1/16 Re 15 – 20 mln grid cells
Runs with Modeled Conditions Kuznetsova et al, 2004 Solar Wind Parameters: N = 2 cm –3 , T = 20,000 Ko, Vx = 300 km/s, |B| = 5 nT IMF Turning From Northward Orientation (θ= 0) to IMF Clock angleθ < 120o:
Sub-Solar FTE Structure Theta = 120o BATSRUS Cluster Pressure Masha_Kuznetsova_031704_4a Pressure
Vortices Generation at the Flanks Close to regions of large flow velocity shear and almost anti-parallel magnetic field. Theta = 120o
Vortices at the Flanks for Southward IMF Theta = 180o Joe_Borovsky_040207_1c
THEMIS Dayside Event: May 20, 2008, 20:30 – 22:30 Solar wind propagated from ACE to 33 Re Global Magnetosphere at 22:00 Resolution at Dayside Magnetopause: 1/16 Re
Weak Magnetic Field Cavity Follows the FTE. Time: 20:51:10 UT Magnetic field (|B|) Pressure (P) Density (N) Velocity (|V|)
Significant Deviations from 2D Tilted Flux Tube Z = - 1.5 Re Slice - 1 Re - 2 Re + 1 Re
View from the Sun Start points for field line tracing at Z = - 1.5 Re slice
Component Reconnection Near Sub-Solar Region (Y ~ 0 – 2 Re) And Anti-Parallel Reconnection at Flanks (Y ~ 12 - 15 Re)
FTE at Flanks (Y = 12 Re) is Connected to FTE at the Sub-Solar Region ( Y = 0 ). X-slice Y-slice Z-slice
Slices Through FTE Magnetic Field Strength X = 1 |Y – 15| < 2 Y = 0 Z = - 1.5 |Y - 12| < 2 Time: 20:51:10 UT
Slice Through FTE: Y = 0 Time interval: 20:40 – 21:00 Magnetic Field Strength
FTE Bulge with Strong Core Field Time: 20:51:10 UT Pressure (P) Magnetic field (|B|) The plasma pressure exhibit a ring-shaped structure surrounding a central depression Density (N) Velocity (|V|) The flow around the flux rope is largest at the magnetosphere side.
Signature of Bended Flux Rope (FTE) Near Sub-Solar Region Y = 0 Y = - 2 Re Y = 2 Re + 2 Re + 2 Re Bended Flux Rope (FTE) Near Sub-Solar Region
Slice Through FTE: X = 1 |Y - 15| < 2 Time interval: 20:40 – 21:00 Magnetic Field Strength