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Observations of the longitudinal spread of solar energetic particle events in solar cycle 24

Cohen, C. M. S. and Mason, G. M. and Wiedenbeck, M. E. and Haggerty, D. K. and Gomez-Herrero, R. and Bucik, R. and Christian, E. R. and Cummings, A. C. and Korth, A. and Labrador, A. W. and Leske, R. A. and Mall, U. and Mewaldt, R. A. and Stone, E. C. and von Rosenvinge, T. T. (2012) Observations of the longitudinal spread of solar energetic particle events in solar cycle 24. In: Physics of the heliosphere: a 10 year retrospective. AIP Conference Proceedings. No.1436. American Institute of Physics , Melville, NY, pp. 103-109. ISBN 978-0-7354-1026-8.

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With the twin STEREO spacecraft, significantly separated from L1-based satellites such as ACE, simultaneous multi-point measurements of solar energetic particle (SEP) events can be made for H-Fe ions from a few hundred keV/nuc to over 100 MeV/nuc and for electrons from tens to hundreds of keV. These observations allow studies of the longitudinal characteristics of SEP events to advance beyond statistical analysis of single point measurements. Although there have been few large SEP events thus far in cycle 24, there have been a number of smaller events that have been detected by more than one spacecraft. The composition of these SEP events, as indicated by the H/He and Fe/O abundance ratios, shows a dependence on longitudinal distance from the solar source in some events, at times with ratios varying by an order of magnitude. However, these variations are not organized by either the speed or width of the associated coronal mass ejections.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Cohen, C. M. S.0000-0002-0978-8127
Mason, G. M.0000-0003-2169-9618
Wiedenbeck, M. E.0000-0002-2825-3128
Haggerty, D. K.0000-0001-6395-8943
Christian, E. R.0000-0003-2134-3937
Cummings, A. C.0000-0002-3840-7696
Labrador, A. W.0000-0001-9178-5349
Leske, R. A.0000-0002-0156-2414
Mewaldt, R. A.0000-0003-2178-9111
Stone, E. C.0000-0002-2010-5462
Additional Information:© 2012 American Institute of Physics. This work was funded by NASA under grants NNX08AI11G and NNX10AQ68G at Caltech, NNX10AT75G at JHUAPL, and subcontracts SA2715-26309 from UC Berkeley (NASA contract NAS5-03131) and N00173-10-1-G010 from NRL. The STEREO/SEPT project is supported under grant 50 OC 0902 by the German Bundesministerium für Wirtschaft through the Deutsches Zentrum für Luft und Raumfahrt (DLR). We thank Nariaki Nitta for useful discussions regarding solar source identifications. We used data from the CME catalog generated and maintained at the CDAW Data Center by NASA and The Catholic University of America in cooperation with NRL and from the CACTus CME catalog, generated and maintained by the SIDC at the Royal Observatory of Belgium.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Deutsches Zentrum für Luft und Raumfahrt (DLR)50 OC 0902
Subject Keywords:element relative abundance, solar composition, solar coronal mass ejections, solar radiation, solar wind
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2012-20
Series Name:AIP Conference Proceedings
Issue or Number:1436
Classification Code:PACS: 96.50.Vg, 96.60.Vg, 96.60.Q-, 96.50.Pw, 96.60.P-, 96.60.Qe
Record Number:CaltechAUTHORS:20120529-081329347
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31666
Deposited By: Tony Diaz
Deposited On:08 Jun 2012 18:21
Last Modified:09 Nov 2021 19:57

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