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Author Chandra, R. ♦ Pariat, E. ♦ Schmieder, B. ♦ Mandrini, C. H. ♦ Uddin, W.
Source Aryabhatta Research Institute of Observational Sciences (ARIES)
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Magnetic clouds ♦ NOAA 10501
Abstract The geoeffective magnetic cloud (MC) of 20 November 2003 was associated withthe 18 November 2003 solar active events in previous studies. In some of these, it was estimated that the magnetic helicity carried by the MC had a positive sign, as did its solar source, active region (AR) NOAA 10501. In this article we show that the large-scale magneticfield of AR 10501 has a negative helicity sign. Since coronal mass ejections (CMEs)are one of the means by which the Sun ejects magnetic helicity excess into interplanetaryspace, the signs of magnetic helicity in the AR and MC must agree. Therefore, this findingcontradicts what is expected from magnetic helicity conservation. However, using, for thefirst time, correct helicity density maps to determine the spatial distribution of magnetic helicityinjections, we show the existence of a localized flux of positive helicity in the southern part of AR 10501. We conclude that positive helicity was ejected from this portion of the AR leading to the observed positive helicity MC.
Part of series sp261-127
Educational Use Research
Education Level UG and PG
Learning Resource Type Article