HR: 0830h
AN: SA21B-0090    [PDF]
TI: Solar Activity Variations in the Topside Ionosphere
AU: * Venkatraman, S
EM: sarita@utdallas.edu
AF: University of Texas at Dallas, P. O. Box 830688 MS/FO22, Richardson, TX 75083 United States
AU: Heelis, R
EM: heelis@utdallas.edu
AF: University of Texas at Dallas, P. O. Box 830688 MS/FO22, Richardson, TX 75083 United States
AB: The fundamental properties of the topside ionosphere are dependent on the low altitude F region plasma and neutral dynamics. Variations in solar activity can cause pressure gradients to drive neutral winds in the F region. These winds blowing from one hemisphere to another can raise the F peak in one hemisphere and lower it in the other hemisphere. This leads to field aligned motion of plasma in turn affecting composition and temperature in the topside. In this study, data are obtained from the Defense Meteorological Satellite Program (DMSP) satellites for varying levels of solar activity. Variations driven by solar activity within a month (for e.g. during equinox) and for the same months, the average F10.7 level is representative of the sunspot cycle. The aim here is to understand solar activity influences on the topside over periods ranging from many years (for e.g. fraction of a solar cycle) to a few months. During solstices, solar activity will additionally drive variations in E x B drifts and neutral winds responsible for changing the behavior in the topside. The extent to which these variations are seen over a period of a few months versus period of a few years (for e.g. fraction of a solar cycle) will be also investigated by examining daytime and nighttime passes.
DE: 2415 Equatorial ionosphere
DE: 2467 Plasma temperature and density
DE: 2481 Topside ionosphere
SC: SPA - Aeronomy [SA]
MN: 2003 Fall Meeting