Hybrid simulations of the expanding solar wind: Temperatures and drift velocities
Abstract
We study the evolution of the expanding solar wind using a one-dimensional and a two-dimensional expanding box model [Grappin et al., 1993] implemented here within a hybrid code [Liewer et al., 2001]. We first consider a plasma with protons and 5% of alpha particles, without drift between the protons and alphas, considering successively the low-beta and high-beta cases. Then we consider a strong drift between protons and alphas, again separately the low-beta and high-beta case. Without drift, the evolution of the low-beta plasma is adiabatic. In the high-beta plasma without drift, the fire hose instabilities (both parallel and oblique) disrupt the adiabatic evolution. Finally, with a drift, the adiabatic evolution is stopped by the oblique Alfvén instability and the parallel magnetosonic instability for low-beta plasma and for high-beta plasma, respectively. The two instabilities slow down thealphas and heat alphas and protons.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- March 2003
- DOI:
- 10.1029/2002GL016409
- Bibcode:
- 2003GeoRL..30.1211H
- Keywords:
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- Interplanetary Physics: Solar wind plasma;
- Interplanetary Physics: Plasma waves and turbulence;
- Space Plasma Physics: Numerical simulation studies;
- Space Plasma Physics: Waves and instabilities;
- Space Plasma Physics: Wave/wave interactions