Kinetic study of solar wind mass loading and cometary bow shocks

Journal Article · Tue Dec 01 04:00:00 EST 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA12p13409· OSTI ID:5597763

Omidi, N; Winske, D

A detailed numerical study is conducted to understand the kinetic processes associated with solar wind mass loading due to pickup of cometary ions and the formation of cometary bow shocks. Because in this study we are most interested in phenomena which take place over time and spatial scales associated with ion dynamics, electrons are treated as a massless fluid. On the other hand, solar wind protons and heavy cometary ions are treated kinetically. It is found that solar wind deceleration and pickup of cometary ions take place through both the macroscopic electromagnetic fields embedded in the solar wind, as well as the microscopic fields associated with low-frequency electromagnetic waves that are generated by the unstable velocity distribution function of the cometary ions. These electromagnetic waves can grow to very large amplitudes and their nonlinear evolution is controlled by their wave normal angle. At parallel propagation where the waves are noncompressional, parametric instabilities seem to be operative, while the oblique, compressional waves are found to steepen and form shocklets. As for the nature of cometary bow shocks, three different regimes are found, based on the shock normal angle. For shock normal angles at or near 90/sup 0/ (quasi-perpendicular), a typically thin transition region (shock) is formed through steepening of fast magnetosonic pulses. This shock is a pure proton shock in that no sharp change in density or velocity of the cometary ions is observed across the shock. at intermediate shock normal angles (oblique), a much wider transition region is seen where the solar wind is gradually heated and decelerated.

• Research Organization: Institute of Geophysics and Planetary Physics, University of California, Los Angeles
• OSTI ID: 5597763
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A12; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
BASIC INTERACTIONS
COMETS
DYNAMIC LOADS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTROMAGNETIC INTERACTIONS
ELEMENTARY PARTICLES
FERMIONS
FLOW MODELS
FLUID FLOW
HADRONS
INTERACTIONS
IONIZATION
MASS
MATHEMATICAL MODELS
NUCLEONS
PROTONS
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND
THERMAL SHOCK
TRANSONIC FLOW
TURBULENT FLOW
WIND LOADS