Pioneer and Voyager observations of Forbush decreases between 6 and 24 AUA detailed phenomenological description of deep space Forbush decreases is given, using Voyager and Pioneer data. The transient reduction in cosmic ray intensity can be produced by (1) reflection at the shock front; (2) increased modulation associated with the disturbed region behind the shock; (3) a barrier mechanism involving large-scale tangential discontinuities; or (4) particle drifts in the enhanced magnetic field by the post-shock region. The presence of a well-defined precursor peak clearly indicates that particle reflection is important. Forbush decreases appear to be an important component in the long-term modulation.
Document ID
19820046942
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Mcdonald, F. B. (New Hampshire Univ. Durham, NH, United States)
Trainor, J. H. (New Hampshire, University Durham, NH, United States)
Webber, W. R. (NASA Goddard Space Flight Center Laboratory for High Energy Astrophysics, Greenbelt, MD, United States)