A Multistation Study of Three Sudden Impulses During 1998
Abstract
Sudden impulses, stimulated by step-like changes in solar wind pressure, provide opportunities to study the propagation of ULF waves through Earth's magnetosphere-ionosphere system. We report here on high latitude ground-based observations of three SI events, on April 23, May 15, and May 29, 1998, that occurred near local noon in the American sector. Observations from fluxgate magnetometers in the cusp-latitude MACCS array in Arctic Canada and roughly conjugate U.S. and British sites in Antarctica are used to map out the horizontal propagation of the preliminary impulse of each SI across the high latitude ionosphere. In addition, search coil magnetometer data are used to determine the time of the first appearance of Pc 1-2 pulsations, which are presumably stimulated by the compression of plasma in the outer dayside magnetosphere, and signals from the auroral 427.8 nm photometer at South Pole Station are used to determine the time of arrival of the first precipitated energetic electrons associated with the SI. Comparisons of these arrival times will be used to infer the mode(s) of propagation of information about the SI from the outer magnetosphere to the cusp-latitude ionosphere.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2002
- Bibcode:
- 2002AGUSMSM42A..10R
- Keywords:
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- 2752 MHD waves and instabilities