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Cosmic ray transverse gradient for a Hale cycleWe have used neutron monitor data obtained at Deep River and Huancayo as well as the vertical underground telescope data obtained at Embudo to compute the cosmic ray transverse gradient (G(sub theta)) for the 1965 to 1990 period. The computed mean value of G(sub theta) for a given qA epoch, changes sign with the change in the solar magnetic polairty in accordance with the predictions of some contemporary hypotheses. Also, we find that the magnitude of G(sub theta) undergoes a significant time variation during a given polarity epoch. It has the largest value near the solar polar field reversal epoch boundaries, when magnetic polarity in the solar northern hemisphere is positive (qA greater than O). For each of the three solar polar field reversals, the change in the magnitude of G(sub theta) is steeper across the epoch boundaries. There is a good correlation between G(sub theta) and the tilt angle of the helisopheric neutral current sheet (HNCS). Our results are in agreement with the reported piecemeal measurements of the latitudinal gradient made by spacecrafts, at different times, at lower primary energies, at far off distances from Earth's orbit. As such, their global significace is appreciable. Even so, it is not clear yet how these findings reflect upon the drift hypothesis in its present form. However, they do affirm the important role played by the tilt angle of HNCS in the modulation processes.
Document ID
19950048204
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ahluwalia, H. S.
(Univ. of New Mexico, Albuqerque, NM United States)
Date Acquired
August 16, 2013
Publication Date
December 1, 1994
Publication Information
Publication: Journal of Geophysical Research
Volume: 99
Issue: A12
ISSN: 0148-0227
Subject Category
Solar Physics
Accession Number
95A79803
Funding Number(s)
CONTRACT_GRANT: NAGW-1468
Distribution Limits
Public
Copyright
Other

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