Assimilative modeling of equatorial plasma depletions observed by C/NOFS

Abstract

Using electric field measurements as inputs, the assimilative physics-based ionospheric model (PBMOD) successfully reproduced density depletions observed at early morning local times during four consecutive orbits of the Communication/Navigation Outage Forecasting System (C/NOFS) satellite on 17 June 2008. However, the PBMOD running with plasma drift data from empirical models as inputs predicted neither plasma depletions nor irregularities on this day. Coincident over flights of a large depletion by C/NOFS and the DMSP-F17 satellite allow estimates of its longitudinal and latitudinal scale sizes. The satellite-based estimates are shown to be in reasonable agreement with PBMOD predictions. The model's reproduction of observed temporal and spatial distributions of plasma depletions suggests that our assimilative technique can be used to enhance space-weather forecasts.