Abstract
Traveling from the ecliptic to the solar polar regions, Ulysses observed wave activity below the local electron cyclotron frequency, fce. In regions near the heliospheric current sheet (hereafter HCS regions), two wave modes are observed: (1) whistler mode electromagnetic waves near interplanetary shocks and during periods of rapidly increasing solar wind velocity, and (2) apparently electrostatic waves occurring during the periods when gradually decreasing solar wind velocity is observed. At high heliographic latitudes, in the region with relatively steady high speed solar wind streams, wave activity is consistently observed near and below fce with little time variability of the spectra. It is found that in the periods when intense waves of the second type are observed in the HCS regions, the electron heat flux decreases. This may imply that these low frequency waves limit the intensity of the heat flux through wave particle scattering.
Original language | English (US) |
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Pages (from-to) | 877-881 |
Number of pages | 5 |
Journal | Advances in Space Research |
Volume | 19 |
Issue number | 6 |
DOIs | |
State | Published - 1997 |
Bibliographical note
Funding Information:NL thanks S. P. Gary for helpful discussions and D. Thayer of the University of Minnesota for assistance in data processing. The URAP experiment is a collaboration of NASA/Goddard Space Flight Center, the Observatoire de Paris-Meudon, the University of Minnesota, and the Centre des Etudes Terrestres et Planetaires, Velizy, France. The work at Los Alamos was carried out under the auspices of the U.S. Department of Energy with support from NASA.