The 17–22 October (1999) solar-interplanetary-geomagnetic event: Very intense geomagnetic storm associated with a pressure balance between interplanetary coronal mass ejection and a high-speed stream

	Become an AGU Member Subscribe to AGU Journals



Read Full Article (file size: 1417451 bytes) Cited by JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, A07S14, doi:10.1029/2005JA011394, 2006 The 17–22 October (1999) solar-interplanetary-geomagnetic event: Very intense geomagnetic storm associated with a pressure balance between interplanetary coronal mass ejection and a high-speed stream Alisson Dal Lago Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Walter D. Gonzalez Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Laura A. Balmaceda Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany Luis E. A. Vieira Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Ezequiel Echer Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Fernando L. Guarnieri Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Jean Santos Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany Marlos R. da Silva Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Aline de Lucas Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Alicia L. Clua de Gonzalez Instituto Nacional de Pesquisas Espaciais, São José dos Campos, São Paulo, Brazil Ranier Schwenn Max-Planck-Institut für Sonnensystemforschung, Katlenburg-Lindau, Germany Nelson J. Schuch Centro Regional Sul de Pesquisas Espaciais, Santa Maria, Rio Grande do Sol, Brazil Abstract Using observations from the Advanced Composition Explorer (ACE) magnetic field and plasma experiments, we investigate the magnetic, thermal, and dynamic pressure balance in the border of a high-speed stream (HSS) and an average-speed interplanetary coronal mass ejection (ICME) observed on 21–22 October (1999). We believe that the HSS compressed the ICME and intensified its internal southward magnetic field, resulting in a very intense geomagnetic storm, with peak Dst of −237 nT. In solar cycle 23 this was the only event, out of 18 very intense geomagnetic storms, i.e., peak Dst < −200 nT, which was caused by such a mechanism. We also address the solar origin of this very intense geomagnetic storm, using combined solar data from three different sources: a ground-based source, coronal hole maps from the National Solar Observatory (NSO) at Kitt Peak, and two satellite-based sources, eruption activity from the Extreme Ultraviolet Imaging Telescope (EIT) and coronal mass ejection observations from the Large Angle and Spectrometric Coronagraph (LASCO), both aboard the Solar and Heliospheric Observatory (SOHO). A coronal hole is evident just beside (to the east of) the active region from which an average-speed coronal mass ejection lifted off on 17–18 October (1999). This was the only possible solar origin of the 21–22 October interplanetary geomagnetic event. Received 31 August 2005; accepted 28 March 2006; published 22 June 2006. Keywords: coronal mass ejections; geomagnetic storms; speed streams. Index Terms: 2788 Magnetospheric Physics: Magnetic storms and substorms (7954); 7513 Solar Physics, Astrophysics, and Astronomy: Coronal mass ejections (2101); 7511 Solar Physics, Astrophysics, and Astronomy: Coronal holes; 2111 Interplanetary Physics: Ejecta, driver gases, and magnetic clouds; 2102 Interplanetary Physics: Corotating streams. Read Full Article (file size: 1417451 bytes) Cited by Citation: Dal Lago, A., et al. (2006), The 17–22 October (1999) solar-interplanetary-geomagnetic event: Very intense geomagnetic storm associated with a pressure balance between interplanetary coronal mass ejection and a high-speed stream, J. Geophys. Res., 111, A07S14, doi:10.1029/2005JA011394. Copyright 2006 by the American Geophysical Union.

Abstract