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Two components in major solar particle events

Cane, H. V. and von Rosenvinge, T. T. and Cohen, C. M. S. and Mewaldt, R. A. (2003) Two components in major solar particle events. Geophysical Research Letters, 30 (12). Art. No. 8017. ISSN 0094-8276. doi:10.1029/2002GL016580.

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A study has been made of 29 intense, solar particle events observed in the energy range 25–80 MeV/nuc near Earth in the years 1997 through 2001. It is found that the majority of the events (19/29) had Fe/O ratios that were reasonably constant with time and energy, and with values above coronal. These all originated on the Sun's western hemisphere and most had intensities that rose rapidly at the time of an associated flare (and coronal mass ejection). Interplanetary shocks observed near Earth had little effect on particle intensities during these events. The remaining 10 events had different intensity-time profiles and Fe/O ratios that varied with time and energy with event-averaged values at or below coronal. Most of these originated near central meridian and 6 had strong interplanetary shocks that were observed near Earth. There were four events with two peaks in the intensity-time profiles, the first near the time of the associated flare (with high Fe/O) and the other at shock passage (with a lower Fe/O) suggesting that solar particle events have two components. At high rigidities the first component (probably flare generated) usually dominates and interplanetary shock-accelerated particles (forming the second component) make a minor contribution except in the case of unusually fast shocks.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Cohen, C. M. S.0000-0002-0978-8127
Mewaldt, R. A.0000-0003-2178-9111
Additional Information:© 2003 by the American Geophysical Union. Received 8 November 2002; revised 31 January 2003; accepted 6 February 2003; published 24 May 2003. This research was partially supported by NASA under grant NAG5-6912. HVC was partially funded by a NASA contract with USRA.
Group:Space Radiation Laboratory
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Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2003-61
Issue or Number:12
Record Number:CaltechAUTHORS:20150323-134235895
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Official Citation:Cane, H. V., T. T. von Rosenvinge, C. M. S. Cohen, and R. A. Mewaldt (2003), Two components in major solar particle events, Geophys. Res. Lett., 30, 8017, doi:10.1029/2002GL016580, 12
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:55976
Deposited By: Deborah Miles
Deposited On:24 Mar 2015 17:21
Last Modified:10 Nov 2021 20:53

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