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Detailed Reference Information |
Goldstein, B.E., Neugebauer, M. and Smith, E.J. (1995). Alfvén waves, alpha particles, and pickup ions in the solar wind. Geophysical Research Letters 22: doi: 10.1029/95GL03182. issn: 0094-8276. |
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Past studies of the properties of Alfv¿n waves in the solar wind have indicated that (1) the amplitude of the velocity fluctuations is almost always smaller than expected on the basis of the amplitude of the field fluctuations, even when the anisotropy of the plasma is taken into account, and (2) the alpha particles often do not participate in the wave motions because they ''surf'' on the waves carried by the proton fluid. Ulysses data are used to demonstrate that (1) the discrepancy between the velocity and field fluctuations is greater at high heliographic latitudes than in the ecliptic plane, and (2) the alphas do participate in the waves, being either in phase or out of phase with the proton motions depending on whether the differential flow speed between the alphas and protons is greater than or less than the ''observed'' wave speed, Vwave=ΔVB0/ΔB, as determined from the ratio of amplitudes of velocity and magnetic fluctuations. The possibility that the modification of Alfv¿n wave propagation speed is due to pressure anisotropies resulting from pickup ion distributions is investigated. ¿ American Geophysical Union 1995 |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Interplanetary Physics, MHD waves and turbulence, Interplanetary Physics, Pickup ions, Interplanetary Physics, Solar wind plasma |
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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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