HR: 16:50h
AN: SH52B-04    [PDF]
TI: Towards a Predictive Model of Low Latitude Ionospheric Space Weather
AU: * Keskinen, M
EM: keskinen@ppd.nrl.navy.mil
AF: Charged Particle Physics Branch, Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave., S.W., Washington, DC 20375 United States
AU: Ossakow, S L
EM: ossakow@ccf.nrl.navy.mil
AF: Plasma Physics Division, Naval Research Laboratory, 4555 Overlook Ave., S.W.,, Washington, DC 20375 United States
AU: Fejer, B G
EM: bfejer@cc.usu.edu
AF: Utah State University, CASS, Logan, UT 84322 United States
AB: Space weather in the earth's equatorial ionosphere, in the form of rising bubble structures, can have significant effects on space-based satellite communications and navigation system and, as a result, have important societal consequences. For example, the Global Positioning System (GPS) can suffer severe scintillation and fading due to the ionospheric density structures associated with equatorial ionospheric bubbles. The development of a predictive model of equatorial ionospheric bubbles will help to mitigate against the deleterious effects of low latitude ionospheric structure and variability. A fully three-dimensional model of the evolution of equatorial ionospheric bubbles is needed to develop a predictive capability. Using numerical simulation techniques we have studied the 3D linear and nonlinear evolution of equatorial ionospheric bubbles. The background ionosphere used to initialize the 3D mesoscale bubble model is computed from a first-principles macroscale equatorial fountain model. Near the prereversal enhancement the 3D mesoscale bubble model is initialized using the background parameters over the entire geomagnetic flux tube. We find that bubble-like structures with extremely sharp gradients can be generated off the equator at anomaly latitudes. We study the effects of various parameters, e.g., prereversal drifts, neutral wind effects, background Pedersen conductivity, and parallel conductivity on the evolution and triggering of equatorial bubbles. Initial studies using data assimilation will be presented as well as comparision with experimental data.
DE: 2100 INTERPLANETARY PHYSICS
DE: 2400 IONOSPHERE
DE: 2700 MAGNETOSPHERIC PHYSICS
DE: 7500 SOLAR PHYSICS, ASTROPHYSICS, AND ASTRONOMY
DE: 7800 SPACE PLASMA PHYSICS
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting