Paper#: 106
Poster #:
Session Name: Workshop 1B: High Latitude Processes
Room: West Ballroom
Day: Monday
Time: 1:55-2:15 p.m.
Abstract Title: Implications of Ionospheric Substorm Electrodynamics Model
PresentSurname: Gjerloev, J.W.
All Authors: J.W. Gjerloev, R.A. Hoffman
Abstract : A three dimensional current system model has been developed for the nighttime sector during the expansion phase through early recovery phase of bulge-type auroral substorms. This model was derived from height integrated horizontal ionospheric currents calculated from models of the height integrated conductivity and convection electric field models previously published. These models were based on a set of data from the Dynamics Explorer 2 satellite taken and organized on the basis of global auroral images from Dynamics Explorer 1. In contrast to a simple downward current post-midnight and upward current pre-midnight forming the substorm current wedge, we find the feeding as well as the drainage of the current wedge component of the westward electrojet is due principally to an imbalance of the downward region 0 and upward region 1 current sheets under which the electrojet is flowing. The total nightside westward electrojet has two maxima, one in the post-midnight bulge, most of which returns to the magnetosphere by midnight, the other in the surge. Emphasis will be put on tracing the field-aligned currents into the magnetosphere as well as validation of the model using magnetometer data from other substorm events.