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Title: Pronounced proton core temperature anisotropy, ion differential speed, and simultaneous Alfven wave activity in slow solar wind at 0. 3 AU

Journal Article · · J. Geophys. Res.; (United States)

In the Helios 2 perihelion (0.3 AU) im May 1978, pronounced ion differential speeds ..delta..v/sub o/p>0 and large proton temperature anisotropies T/sub parallelp//T/sub perpendicularp/<1 have been observed in slow solar wind, in distinct contrast to earlier observations during the phase of solar activity minimum. These features of ion distributions occurred simultaneously with high Alfvenic wave activity. Coulomb friction between the two ion species can be shown to play a minor role, thus obviously favouring the establishment of a large differential ion speed by preferentially accelerating wave forces. The observations may also indicate that strong waves sometimes only heat the protons without creating a fast solar wind.

Research Organization:
Max-Planck-Institut fuer Aeronomie, 3411 Katlenburg-Lindau 3, Federal Republic of Germany
OSTI ID:
5873536
Journal Information:
J. Geophys. Res.; (United States), Vol. 86:A11
Country of Publication:
United States
Language:
English