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Detailed Reference Information |
Meyer-Vernet, N. and Issautier, K. (1998). Electron temperature in the solar wind: Generic radial variation from kinetic collisionless models. Journal of Geophysical Research 103: doi: 10.1029/98JA02853. issn: 0148-0227. |
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We calculate analytically the radial profile of the average electron temperature in the solar wind with a kinetic collisionless model. The electron temperature profile at large distances r is the sum of a term ∝r-4/3 plus a constant, with both terms of the same order of magnitude near r~1 AU. This result is generic as it is weakly dependent on the particle velocity distributions in the corona. It provides a natural explanation for the observed electron temperature profile near 1 AU, which is in the low or middle part of the range between isothermal and adiabatic behaviors. The r-4/3 term comes from the isotropically distributed electrons confined by the heliospheric electric potential, which is found to have a similar radial variation. The constant term comes from the parallel temperature of the electrons energetic enough to escape. The calculated profile flattens as r increases and tends to be flatter in the high-speed wind. We also give simple explicit expressions for the electron temperature and density at large distances and for the terminal wind velocity as a function of coronal parameters when the electron velocity distribution is a Kappa function, which is close to a Maxwellian with a suprathermal tail. ¿ 1998 American Geophysical Union |
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Abstract |
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Keywords
Interplanetary Physics, Solar wind plasma, Space Plasma Physics, Kinetic and MHD theory, Interplanetary Physics, General or miscellaneous, Solar Physics, Astrophysics, and Astronomy, General or miscellaneous |
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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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