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A survey of anisotropic energetic particle flows observed by STEREO

Leske, R. A. and Cohen, C. M. S. and Dotson, B. and Mewaldt, R. A. and Cummings, A. C. and Labrador, A. W. and Stone, E. C. and Wiedenbeck, M. E. and Christian, E. R. and von Rosenvinge, T. T. (2013) A survey of anisotropic energetic particle flows observed by STEREO. In: Solar Wind 13: Proceedings of the Thirteenth International Solar Wind Conference. AIP Conference Proceedings. No.1539. American Institute of Physics , Melville, NY, pp. 227-230. ISBN 978-0-7354-1163-0.

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The Low Energy Telescopes (LETs) onboard the twin STEREO spacecraft have been measuring the anisotropies of energetic particles since before the beginning of solar cycle 24. Large unidirectional anisotropies often appear at the onset of magnetically well-connected solar energetic particle (SEP) events, suggesting beamed particles with relatively little scattering. Also, long-lasting bidirectional flows are seen during the decay phase of several SEP events. Some of these instances appear to be within interplanetary coronal mass ejections (ICMEs), as indicated by characteristics such as magnetic field rotations or bidirectional suprathermal electrons. We present preliminary findings from a survey of LET proton anisotropy observations, which illustrate that bidirectional flows appear more likely to come from directions far from the nominal Parker spiral direction than do unidirectional beams, consistent with previous studies. Individual cases that show unusual intensity depletions perpendicular to the magnetic field or pitch angle distributions otherwise indicative of magnetic mirroring are presented in more detail.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Leske, R. A.0000-0002-0156-2414
Cohen, C. M. S.0000-0002-0978-8127
Mewaldt, R. A.0000-0003-2178-9111
Cummings, A. C.0000-0002-3840-7696
Labrador, A. W.0000-0001-9178-5349
Stone, E. C.0000-0002-2010-5462
Wiedenbeck, M. E.0000-0002-2825-3128
Christian, E. R.0000-0003-2134-3937
Additional Information:© 2013 AIP Publishing LLC. This work was supported by the National Aeronautics and Space Administration (NASA) at Caltech and JPL under sub-contract SA2715-26309 from the University of California at Berkeley under NASA contract NAS5- 03131, and by NASA award NNX08AK87G. We thank the MAG investigators on STEREO formaking their data publicly available.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
University of California BerkeleyUNSPECIFIED
Subject Keywords:Solar energetic particles, anisotropies, STEREO
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2013-19
Series Name:AIP Conference Proceedings
Issue or Number:1539
Classification Code:PACS: 96.50.-e,, 96.50.Vg
Record Number:CaltechAUTHORS:20130625-131632943
Persistent URL:
Official Citation:A survey of anisotropic energetic particle flows observed by STEREO R. A. Leske, C. M. S. Cohen, B. Dotson, R. A. Mewaldt, A. C. Cummings, A. W. Labrador, E. C. Stone, M. E. Wiedenbeck, E. R. Christian, and T. T. von Rosenvinge, AIP Conf. Proc. 1539, 227 (2013), DOI:10.1063/1.4811029
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:39089
Deposited On:26 Jun 2013 14:38
Last Modified:09 Nov 2021 23:42

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