Please use this identifier to cite or link to this item:
Title: The response of the magnetosphere to the passage of a coronal mass ejection on March 20-21 1990
Authors: Taylor, J. R.
Lester, M.
Yeoman, T. K.
Emery, B. A.
Knipp, D. J.
Orr, D.
Solovyev, S. I.
Hughes, T. J.
Luhr, H.
First Published: 1-Jun-1997
Publisher: European Geosciences Union (EGU), Copernicus Publications, Springer Verlag (Germany)
Abstract: The geomagnetic response to the passage of a coronal mass ejection (CME) is studied. The passage of the CME resulted in a storm sudden commencement (SSC) at 2243 UT on March 20 1990 with disturbed magnetic activity during the following 24 h. The auroral, sub-auroral and equatorial magnetic response to the southward turning at 1314 (±5) UT on March 21 and the equatorial response to the southward turning associated with the SSC on 20 March are discussed in terms of existing models. It is found that the auroral and sub-auroral response to the southward turning associated with the SSC is a factor 2 or more quicker than normal due to the shock in the solar wind dynamic pressure. The low-latitude response time to the southward turning, characterised by Dst and the magnetopause current corrected Dst*, is unaffected by the shock. Dst and Dst*, characteristic of the equatorial magnetic field, responded to the 1314 (±5) UT southward turning prior to the first observed substorm expansion phase onset, suggesting that a dayside loading process was responsible for the initial enhancement in the ring current rather than nightside particle injection. The response time of the auroral and sub-auroral magnetic field to the southward turning at 1314 (±5) UT on March 21 is measured at a variety of longitudes and latitudes. The azimuthal propagation velocity of the response to the southward turning varied considerably with latitude, ranging from ~8 km s–1 at 67°N to ~4 km s–1 at 55°N. The southward velocity of the equatorward boundary of the northern polar convection pattern has been measured. This velocity was ~1.2 km s–1 at 1600 MLT, although there was evidence that this may vary at different local times.
DOI Link: 10.1007/s005850050483
ISSN: 0992-7689
eISSN: 1432-0576
Type: Journal Article
Rights: Archived with reference to SHERPA/RoMEO and publisher website. © European Geosciences Union 1997 Version of record:
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

Files in This Item:
File Description SizeFormat 
angeo-15-671-1997.pdf2.25 MBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.