REINTERPRETATION OF SLOWDOWN OF SOLAR WIND MEAN VELOCITY IN NONLINEAR STRUCTURES OBSERVED UPSTREAM OF EARTH'S BOW SHOCK
- Space Sciences Laboratory, University of California, Berkeley, CA (United States)
- School of Space Research, Kyung Hee University, Yongin, Gyeonggi (Korea, Republic of)
- School of Earth and Space Sciences, Peking University, Beijing (China)
- Earth and Space Sciences, University of Washington, Seattle, WA (United States)
- Beijing University of Aeronautics and Astronautics, 100190, Beijing (China)
- Space Weather, National Space Science Center, Beijing (China)
- NASA, Goddard Space Flight Center, Greenbelt, MD (United States)
- Laboratory for Plasma Physics, Ecole Polytechnique, Paris (France)
- CNRS, IRAP, 9 Ave. Colonel Roche, Toulouse (France)
Two of the many features associated with nonlinear upstream structures are (1) the solar wind (SW) mean flow slows down and deviates substantially and (2) the temperature of the plasma increases in the structure. In this Letter, we show that the SW beam can be present throughout the entire upstream event maintaining a nearly constant beam velocity and temperature. The decrease of the velocity is due to the appearance of new particles moving in the opposite direction that act against the SW beam and reduce the mean velocity as computed via moments. The new population, which occupies a larger velocity space, also contributes to the second moment, increasing the temperature. The new particles include the reflected SW beam at the bow shock and another population of lower energies, accelerated nearby at the shock or at the boundary of the nonlinear structures.
- OSTI ID:
- 22118691
- Journal Information:
- Astrophysical Journal Letters, Vol. 771, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
Large amplitude MHD waves upstream of the Jovian bow shock: reinterpretation
Observational test of shock drift and fermi acceleration on a seed particle population upstream of the Earth's bow shock