Long-Term Temporal Behavior of Interplanetary and Trapped Anomalous Cosmic Rays
Abstract
New measurements of the long-term temporal history of anomalous cosmic rays (ACRs) at 1 AU are presented, based on data from SAMPEX and ACE. Over the period from 1992 to 1997 the interplanetary intensity of 8 to 27 MeV/nuc ACR oxygen increased by a factor of -5 as solar minimum approached. The intensity of ACR oxygen trapped in the Earth's magnetosphere showed a corresponding time history. Early in 1998 both the interplanetary and trapped intensities suddenly decreased with the onset of solar activity leading to the next solar maximum. We discuss the relation of the time-delay between changes in the interplanetary and trapped fluxes, possible solar/interplanetary causes of these changes, and the lifetime of trapped ACRs in Earth's magnetosphere.
Additional Information
This work was supported by NASA under grants NAGS-2963 and NAGS-6912 at Caltech, and at the Jet Propulsion Laboratory and the Goddard Space Flight Center.Attached Files
Published - 1999-23.pdf
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Additional details
- Eprint ID
- 54781
- Resolver ID
- CaltechAUTHORS:20150212-105955417
- NASA
- NAGS-2963
- NASA
- NAG5-6912
- Created
-
2015-02-13Created from EPrint's datestamp field
- Updated
-
2020-03-09Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 1999-23