ISTP resources have been used to illustrate the reality of a direct and prompt (~1 hr) response of polar ionospheric plasma outflows to CME-generated magnetic clouds in the solar wind, consistent with a statistical data set from the '80s. The results are consistent with strong ionospheric bulk heating driven principally by variations of the solar wind dynamic pressure and probably mediated by enhanced dayside field-aligned current systems. The result was a cloud of dense, relatively cold ionospheric outflow that is delivered through the magnetospheric lobes to the near-Earth plasma sheet, where it may have impacts on the occurrence of dynamic behaviors related to substorms and storms, such as reconnection, dipolarization, and localized bursty bulk flows. It will clearly be important to extend the statistical study through solar maximum, and to monitor the dayside heating and outflow region with greater time resolution and more comprehensive spatial coverage, so as to gain further clues as to the detailed mechanisms of the solar wind interaction with this important region.
© 1999 American Geophysical Union