How big was the Carrington 1859 Flare?
Abstract
The 1859 space weather event was distinguished by its great geomagnetic storm, widespread low-latitude aurora, and intense solar energetic particle event (inferred from the NO3 concentration in polar ice cores). Arguably each of these three effects was the largest ever observed. What can we say about the size of the associated solar flare? We have two observations with which to make such an assessment: (1) Carrington's and Hodgson's report of the white-light flare and (2) the solar flare effect or magnetic crochet observed in the Kew and Greenwich magnetograms. Estimates of the area, duration, spectrum, and intensity of the white-light emission indicate a large (~2 x 1030 erg) but not unequalled event (the white-light emission of the 24 April 1984 >X13 flare contained ~6 x 1030 erg). The magnetic crochet of 130 nT in the horizontal force, however, exceeds that for all >X10 soft X-ray flares observed from 1984-2002 (we are presently compiling magnetic data for the recent October-November 2003 activity for comparison with the 1859 event). Thus at this point, we can conservatively say that Carrington's flare likely had a soft X-ray classification >X10 and was at least comparable to the largest flares recorded during the spacecraft era.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2004
- Bibcode:
- 2004AGUSMSH43A..03C
- Keywords:
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- 1739 Solar/planetary relationships;
- 2788 Storms and substorms;
- 7519 Flares