Three-dimensional simulation of equatorial spread-F with meridional wind effects

Abstract

The NRL SAMI3 three-dimensional simulation code is used to examine the effect of meridional winds on the growth and suppression of equatorial spread F (ESF). The simulation geometry conforms to a dipole field geometry with field-line apex heights from 200 to 1600 km at the equator, but extends over only 4 degrees in longitude. The full SAMI3 ionosphere equations are included, providing ion dynamics both along and across the field. The potential is solved in two dimensions in the equatorial plane under a field-line equipotential approximation. By selectively including terms in the potential equation, the reduced growth predicted by Maruyama (1988) and the stabilization predicted by Zalesak and Huba (1991) are separately realized. We find that ESF is stabilized by a sufficiently large constant meridional wind (60 m/s in our example).