HR: 14:40h
AN: SM53A-05 [Abstracts]
TI: MHD simulations of the transpolar potential response to solar wind density variations
AU: * Ober, D
EM: daniel.ober@atk.com
AF: ATK Mission Research, 589 West Hollis Street
Suite 201, Nashua, NH 03062
United States
AU: Wilson, G
EM: gordonr.wilson@atk.com
AF: ATK Mission Research, 589 West Hollis Street
Suite 201, Nashua, NH 03062
United States
AU: Burke, B
EM: William.Burke2@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Road, Hanscom AFB, MA 01731
United States
AU: Maynard, N
EM: nelson.maynard@atk.com
AF: ATK Mission Research, 589 West Hollis Street
Suite 201, Nashua, NH 03062
United States
AU: Siebert, K
EM: keith.siebert@atk.com
AF: ATK Mission Research, 589 West Hollis Street
Suite 201, Nashua, NH 03062
United States
AB:
Recent analyses of an isolated solar wind density pulse on 10 January 1997, while the interplanetary electric field remained
steady, identified a dramatic increase in the transpolar potential (TP) from 130 to 220 kV. The TP models of neither Weimer
nor Siscoe-Hill predict such an increase. However, magnetohydrodynamic (MHD) simulations of the event do predict a TP
increase consistent with satellite measurements. The response is transient, decaying on time scales of tens of minutes
toward a final equilibrium close to the original potential. The simulated TP enhancement derives from significant erosion of
the dayside magnetopause and transport of newly opened magnetic flux across the polar cap. The exponential decay of the TP
results from inductance in the magnetosphere-ionosphere circuit. MHD simulation results for different solar wind density
increases/decreases will be presented and discussed. The time dependent TP for varying solar wind density conditions can be
fairly well described using the dayside merging rate derived from the MHD simulations to power an LR circuit model of the
magnetosphere-ionosphere system.
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2753 Numerical modeling
DE: 2784 Solar wind/magnetosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005