Dayside equatorial-plane convection and IMF sector structure
Abstract
Using 1290 hours of GEOS-2 electron gun measurements between 0800 LT and 1900 LT we have analyzed the dependence of dayside magnetospheric convection in the equatorial plane at L=6.6 RE on the IMF sector structure, i.e. IMF By≶0 and IMF Bx≶0. For all IMF sector orientations the plasma flow at noon is directed predominantly sunward with a slight dawnward component. For positive IMF By the plasma convection around 0900 LT has a duskward component which turns into a dawnward component for negative IMF By values. The ratio between the electric field amplitudes at 1500 LT (dusk sector) and those at 0900 LT (dawn sector) increases from about 2 for IMF By positive to 3-4 for negative IMF By components. The convection pattern does neither show a dependence on the Bx component of the IMF nor is it significantly different for gardenhose (Bx.By<0) and nongardenhose (Bx.By>0) orientations of the IMF. These results support the idea of component merging rather than the antiparallel merging hypothesis.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- April 1986
- DOI:
- 10.1029/JA091iA04p04557
- Bibcode:
- 1986JGR....91.4557B
- Keywords:
-
- Convection;
- Earth Magnetosphere;
- Interplanetary Magnetic Fields;
- Magnetohydrodynamic Flow;
- Electric Fields;
- Equatorial Atmosphere;
- Kp Index;
- Space