Coupled Model of StormTime Effects on the Low

Coupled Model of Storm-Time Effects on the Low- and Mid. Latitude Ionosphere • Goals: – To couple the Rice Convection Model to the NRL-developed SAMI 3 ionosphere model. – To use the coupled code to investigate how prompt-penetration electric fields affect the structure of the low- and mid-latitude ionosphere. • Key Motivation: – Basu et al. (GRL, 28, 3577, 2001) observed near disappearance of postdusk equatorial ionosphere during the great magnetic storm of July 15, 2000, apparently due to prompt-penetration electric fields. – Yin et al. (GRL, 31, L 12806, 2004) observed large-scale changes in maps of Total Electron Content during the same storm. • Status: – The codes have been successfully coupled and run for idealized conditions, producing physically reasonable results (next slide). – Next step: to run through a real storm and see if code are quantitavely consistent with observations. 1

Sample Results from Coupled SAMI 3/RCM Code • Plots show differences in height of F 2 peak and Total Electron Content between - Storm case: 80 k. V jump in the polar-cap potential assumed in RCM (from 40 k. V to 120 k. V) - No storm case: No jump in the polar-cap potential (remains constant at 40 k. V) • • Penetration electric fields raised F 2 peak by more than 100 km in post-dusk sector. Fountain effect depleted equatorial ionosphere and strengthened Appleton peaks. 2