Portal de Periódicos da CAPES

Helium and hydrogen velocity differences in the solar wind

1976; American Geophysical Union; Volume: 81; Issue: 16 Linguagem: Inglês

10.1029/ja081i016p02719

2156-2202

J. R. Asbridge, S. J. Bame, W. C. Feldman, M. D. Montgomery,

Astro and Planetary Science

Journal of Geophysical Research (1896-1977)Volume 81, Issue 16 p. 2719-2727 Particles and Fields—Interplanetary Space Helium and hydrogen velocity differences in the solar wind J. R. Asbridge, J. R. AsbridgeSearch for more papers by this authorS. J. Bame, S. J. BameSearch for more papers by this authorW. C. Feldman, W. C. FeldmanSearch for more papers by this authorM. D. Montgomery, M. D. MontgomerySearch for more papers by this author J. R. Asbridge, J. R. AsbridgeSearch for more papers by this authorS. J. Bame, S. J. BameSearch for more papers by this authorW. C. Feldman, W. C. FeldmanSearch for more papers by this authorM. D. Montgomery, M. D. MontgomerySearch for more papers by this author First published: 1 June 1976 https://doi.org/10.1029/JA081i016p02719Citations: 111AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Scalar and vector velocity differences between helium and hydrogen ions in the solar wind measured with the Los Alamos plasma analyzers on Imp 6 and Imp 7 are presented and interpreted. From the bulk speeds and azimuthal components of flow direction for both types of ions the ecliptic projection of the helium to hydrogen velocity difference vector vαp is determined. Short-term and long-term average properties of this vector, at times contrasted with the more usually reported bulk speed difference υα − υp, are principal subjects of this paper. The vector is usually found aligned with the proton heat flux vector Qp and therefore is directed predominantly outward from the sun. Sometimes preceding high-speed streams and during fluctuations the vector is directed back toward the sun; i.e., υp > υα. There is a statistical correlation between the magnitude of vαp and the wind speed; empirically, |vαp| ≃ 0.08υp − 23 for υp ≥ 420 km s−1. During high-speed streams, |vαp| is often 25 or 30 km s−1 and on rare occasions as large as 80 km s−1, while at lower wind speeds it is <10 km s−1. In high-speed streams or in other magnetically disturbed regions the vector difference magnitude often remains nearly constant, while the bulk speed difference undergoes large changes as the difference vector rotates in alignment with B. The underlying physical causes of the He and H speed differences remain undetermined. References Alloucherie, Y., Diffusion of heavy ions in the solar corona, J. Geophys. Res., 75, 6899, 1970. Asbridge, J. R., S. J. Bame, W. C. Feldman, Variations in the helium component of the solar wind (abstract), Eos Trans. AGU, 54, 440, 1973. Asbridge, J. R., S. J. Bame, W. C. Feldman, Abundance differences in solar wind double streams, Solar Phys., 37, 451–467, 1974a. Asbridge, J. R., S. J. Bame, W. C. Feldman, M. D. Montgomery, Helium and hydrogen velocity differences in the solar wind (abstract), Eos Trans. AGU, 56, 1180–1181, 1974b. Bame, S. J., A. J. Hundhausen, J. R. Asbridge, I. B. Strong, Solar wind ion composition, Phys. Rev. Lett., 20, 393, 1968. Bame, S. J., J. R. Asbridge, A. J. Hundhausen, M. D. Montgomery, Solar wind ions: 56Fe+8 to 56Fe+12, 28Si+7, 28Si+8, 28Si+9, and 16O+6, J. Geophys. Res., 75, 6360, 1970. Bame, S. J., J. R. Asbridge, W. C. Feldman, S. P. Gary, M. D. Montgomery, Evidence for local ion heating in solar wind high speed streams, Geophys. Res. Lett., 2, 373, 1975. Belcher, J. W., L. Davis Jr., Large-amplitude Alfvén waves in the interplanetary medium, 2, J. Geophys. Res., 76, 3534, 1971. Belcher, J. W., L. Davis Jr., E. J. Smith, Large-amplitude Alfvén waves in the interplanetary medium: Mariner 5, J. Geophys. Res., 74, 2302, 1969. Bollea, D., V. Formisano, P. C. Hedgecock, G. Moreno, F. Palmiotto, Heos 1 helium observations in the solar wind, Solar Wind C. P. Sonett, P. J. Coleman, J. M. Wilcox, NASA Spec. Publ., 308, 588–597, 1972. Feldman, W. C., J. R. Asbridge, S. J. Bame, M. D. Montgomery, Double ion streams in the solar wind, J. Geophys. Res., 78, 2017–2027, 1973a. Feldman, W. C., J. R. Asbridge, S. J. Bame, M. D. Montgomery, On the origin of solar wind proton thermal anisotropy, J. Geophys. Res., 78, 6451, 1973b. Feldman, W. C., J. R. Asbridge, S. J. Bame, The solar wind He2+ to H+ temperature ratio, J. Geophys. Res., 79, 2319, 1974. Formisano, V., F. Palmiotto, G. Moreno, α-particle observations in the solar wind, Solar Phys., 15, 479, 1970. Gary, S. P., W. C. Feldman, M. D. Montgomery, D. W. Forslund, Proton temperature anisotropy instabilities in the solar wind, J. Geophys. Res., 81, 1976. Geiss, J., Elemental and isotopic abundances in the solar wind, Solar Wind C. P. Sonett, P. J. Coleman, J. M. Wilcox, NASA Spec. Publ., 308, 559–579, 1972. Geiss, J., P. Eberhardt, F. Bühler, J. Meister, P. Signer, Apollo 11 and 12 solar wind composition experiments: Fluxes of He and Ne isotopes, J. Geophys. Res., 75, 5972, 1970a. Geiss, J., P. Hirt, H. Leutwyler, On acceleration and ions in corona and solar wind, Solar Phys., 12, 458–483, 1970b. Hirshberg, J., J. R. Asbridge, D. E. Robbins, The helium component of solar wind velocity streams, J. Geophys. Res., 79, 934–938, 1974. Hollweg, J. V., Alfvénic acceleration of solar wind helium and related phenomena, 1, Theory, J. Geophys. Res., 79, 1357, 1974. Hundhausen, A. J., S. J. Bame, J. R. Asbridge, S. J. Sydoriak, Solar wind proton properties: Vela 3 observations from July 1965 to June 1967, J. Geophys. Res., 75, 4643, 1970. Montgomery, M. D., S. P. Gary, W. D. Forslund, W. C. Feldman, Electromagnetic ion beam instabilities in the solar wind, Phys. Rev. Lett., 35, 667, 1975. Montgomery, M. D., S. P. Gary, W. C. Feldman, D. W. Forslund, Electromagnetic instabilities driven by unequal proton beams in the solar wind, J. Geophys. Res., 81, 1976. Nakada, M. P., A study of the composition of the solar corona and solar wind, Solar Phys., 14, 457, 1970. Neugebauer, M., The role of coulomb collisions in limiting differential flow and temperature differences in the solar wind, J. Geophys. Res., 81, 78, 1976. Neugebauer, M., C. W. Snyder, Mariner 2 measurements of the solar wind, The Solar Wind R. J. Mackin, M. Neugebauer, 3–21, Pergamon, New York, 1966. Ogilvie, K. W., Differences between the bulk speeds of hydrogen and helium in the solar wind, J. Geophys. Res., 80, 1335, 1975. Ogilvie, K. W., H. J. Zwally, Hydrogen and helium velocities in the solar wind, Solar Phys., 24, 236, 1972. Ogilvie, K. W., L. F. Burlaga, T. D. Wilkerson, Plasma observations on Explorer 34, J. Geophys. Res., 73, 6809, 1968. Robbins, D. E., A. J. Hundhausen, S. J. Bame, Helium in the solar wind, J. Geophys. Res., 75, 1178, 1970. Whang, Y. C., Higher moment equations and the distribution function of the solar wind plasma, J. Geophys. Res., 76, 7503, 1971. Yeh, T., A three-fluid model of solar wind, Planet. Space Sci., 18, 199, 1970. Citing Literature Volume81, Issue16Space Physics1 June 1976Pages 2719-2727 ReferencesRelatedInformation