MAPPING IONOSPHERIC CONVECTION RESPONSE TO IMF BY NEGATIVE AND BZ POSITIVE CONDITIONS

We have used the Assimilative Mapping of Ionospheric Electrodynamics ( AMIE) procedure to derive electric potential patterns for a period of strong and slowly varying northward interplanetary Magnetic Field (IMF ). Using these patterns we offer some insight into high-latitude conve ction response to differing IMF conditions between the hours of 0850 a nd 1720 UT on 14 January 1988. We introduce a newly assimilated data s et, Defense Meteorological Satellite Program (DMSP) ion drift measurem ents, as a means of mapping electric fields in polar regions. Also, fo r the first time we map both southern and northern hemisphere convecti on flows. We show that significantly different convection patterns are simultaneously possible in the two polar caps when B(z) is positive, and that asymmetries in these patterns are influenced by the strength of B(y) and B(x). When the ratio \B(y)/B(z)\ exceeds unity the polar c ap convection increases and changes from sunward to anti-sunward for B (z) positive conditions.