Anomalous cosmic rays in the distant heliosphere and the reversal of the Sun's magnetic polarity in Cycle 23
Abstract
Beginning in early June 2001 and extending over a ∼3 month period the Cosmic Ray Subsystem (CRS) experiment on Voyager 1 (80.3 AU, 34°N) observed a rapid transition in the energy of the peak intensity of anomalous cosmic ray (ACR) He from ∼11 MeV/n to ∼25 MeV/n. One month later there began a similar spectral shift at Voyager 2 (64.7 AU, 24°S). When these ACR transition times are extrapolated back from the estimated location of the heliospheric termination shock (TS) to the Sun (∼1 year) there is reasonable agreement with the range of times obtained for the polarity reversal of the interplanetary magnetic field (IPB) in the northern hemisphere near the Sun and the later reversal in the south. We interpret these changes in the ACR spectra as giving a global view of the interplanetary field reversal at the TS and confirmation of the important role of the TS in controlling the ACRs.
Additional Information
© 2007 by the American Geophysical Union. Received 28 November 2006; revised 5 January 2007; accepted 17 January 2007; published 7 March 2007. We thank Yi-Ming Wang of the Naval Research Laboratory, Washington, D.C., for valuable discussions. This work was supported by NASA under contract NAS7-03001.Attached Files
Published - 2007-04.pdf
Supplemental Material - grl22776-sup-0001-t01.txt
Supplemental Material - grl22776-sup-0002-t02.txt
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Additional details
- Eprint ID
- 56034
- Resolver ID
- CaltechAUTHORS:20150324-133810503
- NAS7-03001
- NASA
- Created
-
2015-03-24Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 2007-04