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Space Weather

``Space weather'' is a recent phrase and indeed a buzzword in solar and space physics. It refers broadly to the conditions in space that may affect human activities on Earth and in space. These conditions change in response to solar activity like flares, solar wind phenomena like CMEs, CIRs and periods with southwards IMF (interplanetary magnetic field), and the associated changes in coupling between the ionosphere, magnetosphere, and solar wind. One important point is that the magnetosphere, perhaps even more so than the solar wind, is a dynamic, time-varying entity which responds in complex, poorly understood ways to changes in the solar wind.

This Lecture is set up as follows. The first section contains a general overview of space weather, in which the phenomena, solar-terrestrial relationships, locations, and important effects of space weather events are summarized and then explained in more detail. The second section sets these phenomena in context by describing the space weather events observed during one of the most intense space weather events in recent history, that of March 1989. The final section contains a basic physical model which integrates these observations into an understandable (but incomplete model). At the present time obtaining a detailed understanding and predictive capability for space weather is one of NASA's main goals in Space Physics. Perhaps some of you will be able to help to do this.

Iver Cairns
Thu Sep 23 17:35:28 EST 1999