Summary
Using the MAGE model, we were able to show how the penetrating electric
field varies with IMF Bz and is applied to the low latitudes. We
summarize our findings as follows: 1. MAGE shows during the S-IMF cases,
the dawn-dusk potential at the equator is about 1 tenth of the CPCP. 2.
The dawn-dusk potential at the equator is applied instantaneously as the
IMF Bz turns. 3. The daytime response of the equatorial vertical ion
drift is about half of that during the nighttime, due probably to the
E-region conductance influence. 4. MAGE simulation shows PRE during the
S-IMF case, and PRE is absent in the ICON IVM observation. Further
observations and modeling are needed to resolve this discrepancy.