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Detailed Reference Information |
Langner, U.W., Potgieter, M.S. and Webber, W.R. (2003). Modulation of cosmic ray protons in the heliosheath. Journal of Geophysical Research 108: doi: 10.1029/2003JA009934. issn: 0148-0227. |
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A contemporary numerical model including a solar wind termination shock, a heliosheath, and drifts is used to study the features of cosmic ray proton modulation in the outer heliosphere. Voyager and Pioneer spacecraft observations over 22 years and out to ~82 AU have shown markedly different behavior for minimum modulation conditions between the radial intensity profiles for periods of opposite magnetic polarities and that most of the residual modulation for these periods took place in the outer heliosphere, near and beyond where the termination shock is expected to be. The modeling results show that the inclusion of a termination shock in the modulation model for solar minimum conditions causes abrupt changes in the radial gradients, gr, at the termination shock, at almost all energies of interest to modulation studies. During A > 0 solar magnetic field polarity cycles this barrier effect contributes ~60% to the overall modulation at 0.5 GeV. However, for A 0 cycles, surprisingly more so for higher energies. |
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Abstract |
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Keywords
Interplanetary Physics, Cosmic rays, Interplanetary Physics, Heliopause and solar wind termination, Interplanetary Physics, Discontinuities, Interplanetary Physics, Energetic particles, heliospheric |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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