Paper#: 116
Poster #: 27
Session Name: Poster Session 2
Room: East Ballroom
Day: Thursday
Time: 10:10 a.m.-Noon
Abstract Title: Diversion of Ionospheric O+: A Possible Trigger Mechanism?
PresentSurname: Donovan, E.F.
All Authors: C. M. Cully, E. F. Donovan, A. W. Yau, H. J. Opgenoorth
Abstract : Using a long-term set of ion outflow measurements from the Akebono satellite, we have examined the supply of ionospheric O+ to the central plasma sheet. Although a change in the IMF direction likely has little impact on the number flux of escaping ionospheric O+, the corresponding change in the convection electric field could dramatically alter the flight paths of these ions. Specifically, the supply of oxygen ions to the mid-distant CPS in the pre-midnight sector is shown to decrease dramatically and near-instantaneously following a significant convection decrease, such as could be expected after a northward turning of the IMF. With O+ frequently contributing a dominant portion of the CPS mass, this mechanism may constitute a dramatic decrease in the supply of available current carriers in the moments before substorm onset.