A Caltech Library Service

Evolution of suprathermal seed particle and solar energetic particle abundances

Mewaldt, R. A. and Mason, G. M. and Cohen, C. M. S. and Gómez-Herrero, R. and Haggerty, D. K. and Leske, R. A. and Wiedenbeck, M. E. (2012) Evolution of suprathermal seed particle and solar energetic particle abundances. In: Physics of the heliosphere: a 10 year retrospective. AIP Conference Proceedings. No.1436. American Institute of Physics , Melville, NY, pp. 206-211. ISBN 978-0-7354-1026-8.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We report on a survey of the composition of solar-wind suprathermal tails and solar energetic particles (SEPs) including data from 1998 to 2010, with a focus on 2007 to 2010. The start of solar cycle 24 included several SEP events that were unusually He-poor. We conclude that these He-poor events are more likely related to Q/M-dependent spectral variations than to seed-particle composition changes. We also find that the quiet-time suprathermal Fe/O ratio during the 2008-2009 solar-minimum was dramatically lower (Fe/O ≤ 0.01) than earlier due in part to very low solar activity, but also suggesting contributions from an oxygen-rich source of suprathermal ions of unknown origin.

Item Type:Book Section
Related URLs:
URLURL TypeDescription DOIArticle
Mewaldt, R. A.0000-0003-2178-9111
Mason, G. M.0000-0003-2169-9618
Cohen, C. M. S.0000-0002-0978-8127
Haggerty, D. K.0000-0001-6395-8943
Leske, R. A.0000-0002-0156-2414
Wiedenbeck, M. E.0000-0002-2825-3128
Additional Information:© 2012 American Institute of Physics. NASA funded this work under grant NNX10AT75G at JHU/APL, and at Caltech under grants NNX08AI11G, NNX10AE45G, and subcontract SA2715-26309 from UC Berkeley under NASA contract NAS5-03131. We thank Eberhard Möbius and Nathan Schwadron for helpful discussions.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Subject Keywords:Solar energetic particles, solar wind, pickup ions, solar composition, solar flares
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2012-19
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:20120529-082347635
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:31667
Deposited By: Tony Diaz
Deposited On:08 Jun 2012 18:14
Last Modified:09 Nov 2021 19:57

Repository Staff Only: item control page