HR: 16:15h
AN: SM14A-02    [Abstracts]
TI: Ion-kinetic Mapping Between the Magnetotail and the Ionosphere
AU: * Krauss-Varban, D
EM: varban@ssl.berkeley.edu
AF: Space Sciences Laboratory, UCB, 7 Gauss Way, Berkeley, CA 94720-7450 United States
AU: Karimabadi, H
EM: homa@ece.ucsd.edu
AF: ECE Department, UCSD, 9500 Gilman Dr., La Jolla, CA 92093-0407 United States
AB: Absolute mapping along magnetic field lines between magnetotail locations and their corresponding ionospheric foot points is a notoriously difficult task. On the other hand, it is potentially very rewarding, since many ground based and satellite observations can use the ionosphere to remotely diagnose tail processes. We address the mapping issue with large-scale, 3-D hybrid (kinetic ions, electron fluid) simulations. A numerical equilibrium is created that includes the near-Earth dipolar region and the stretched tail. As in other approaches, the assumptions underlying the modeled tail configuration mean that the mapped features have less absolute meaning than desirable. However, the relative positioning with respect to the open/closed field line boundary and to the background ion precipitation latitude, the dawn-dusk positioning, and the timing of arrival at the ionosphere have long been noted to be very important characteristics. In this study, we focus on signatures related to the extremely thin tail current layer typical for the pre-onset substorm. In particular, we show how Alfvenic perturbations, field-aligned currents, and energetic ions travel in this configuration and map to the ionosphere, with and without localized reconnection taking place.
DE: 2716 Energetic particles, precipitating
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2744 Magnetotail
DE: 2748 Magnetotail boundary layers
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting