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Implications of Time Variations for the Origin of Low Energy Cosmic Ray Nitrogen and Oxygen Nuclei

Mewaldt, R. A. and Stone, E. C. and Vogt, R. E. (1975) Implications of Time Variations for the Origin of Low Energy Cosmic Ray Nitrogen and Oxygen Nuclei. In: Proceedings of the 14th International Cosmic Rays Conference. Vol.2. Max Planck Gesellschaft , pp. 804-809.

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We report observations of time variations in the quiet time intensity of 5-27 MeV/nuc nitrogen and oxygen and 13-25 MeV/nuc helium nuclei, obtained with the Caltech Electron/Isotope Spectrometers on IMP 7 and 8. We find no significant correlation of the O variations with variations in the low intensity fluxes of 1-2 MeV solar protons. However, we do find the O intensity to be well correlated with the modulation of galactic cosmic rays as measured by neutron monitors. When compared with the neutron monitor, the factor of ~ 3 change in the 0 intensity during 1972 through 1974 is consistent with the factor of ~ 30 increase observed since 1969. These observations imply that the enhanced low energy N and O fluxes are not of solar origin, but originate far enough from the sun that they undergo substantial modulation and have significantly increased access to 1 AU at times of minimum solar modulation. It may be possible to determine the charge state of the He and O by comparing their time variations. The He and O variations are strongly correlated, and both exhibit similar hysteresis effects when compared to the neutron monitor.

Item Type:Book Section
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Mewaldt, R. A.0000-0003-2178-9111
Stone, E. C.0000-0002-2010-5462
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Additional Information:© 1975 MPE. Provided by the NASA Astrophysics Data System. This work was supported in part by the National Aeronautics and Space Administration under Contract NAS5-11066 and Grant NGR 05-002-160.
Group:Space Radiation Laboratory
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NASANGR 05-002-160
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Space Radiation Laboratory1975-09
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ID Code:44865
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Deposited On:14 Apr 2014 23:54
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