HR: 09:30h
AN: SA11B-06    [Abstracts]
TI: Towards a Model for Midlatitude Stormtime Ionospheric Mesoscale and Small Scale Structure
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: Basu, S
EM: sbasu@bu.edu
AF: Boston University, Center for Space Physics, Boston, MA 02215 United States
AU: Basu, S
EM: santimay.basu@hanscom.af.mil
AF: AFRL/VSBXP, 29 Randolph rd, Hanscom AFB, MA 01731 United States
AB: The response of the midlatitude ionosphere to geomagnetic storms is governed by several factors, e.g., magnetospheric leakage electric fields, dynamo action of thermospheric winds driven equatorward by auroral heating, and the equatorward propagation of fast time scale ionospheric waves and disturbances. Inner magnetospheric electric fields may generate sub-auroral polarization streams (SAPS). Equatorward of SAPS strong ionospheric coupling to plasmaspheric tail-like structures can occur. Several studies have addressed the large scale midlatitude ionospheric and thermospheric response to magnetic storms. However few quantitative models for the mesoscale and small scale structure and dynamics of the midlatitude stormtime ionosphere have been developed. Both ground and space-based observations have shown that the midlatitude stormtime ionosphere can be highly structured down to meter scale sizes. This structure appears to be located in and near the auroral - sub auroral boundary region. Recently, we have shown that SAPS can become structured due to gradient-driven processes in the presence of strong convection. A preliminary composite model for midlatitude stormtime mesoscale and small scale ionospheric structure, which combines auroral and sub-auroral irregularity generation mechanisms, is presented.
DE: 2435 Ionospheric disturbances
DE: 2439 Ionospheric irregularities
DE: 2443 Midlatitude ionosphere
DE: 2447 Modeling and forecasting
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting