Slow shocks and their transition to fast shocks in the inner solar wind

Journal Article · Fri May 01 04:00:00 EDT 1987 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA092iA05p04349· OSTI ID:6401939

Wang, Y C

The jump conditions of MHD shocks may be directly calculated as functions of three upstream conditions: the shock Alfven number based on the normal component of the relative shock speed, the shock angle, and the plasma ..beta.. value. The shock Alfven number is less than 1 for a slow shock and greater than 1 for a fast shock. A traveling, forward shock can be a slow shock in coronal space, where the Alfven speed is of the order of 1000 km/s. The surface of a forward slow shock has a bow-shaped geometry with its nose facing toward the sun. The decrease in the Alfven speed at increasing heliocentric distance causes the shock Alfven number of a forward slow shock to become greater than 1, and the shock eventually evolves from a slow shock into a fast shock. During the transition the shock system consists of a slow shock, a fast shock, and a rotational discontinuity. They intersect along a closed transition line. As the system moves outward from the sun, the area enclosed by the transition line expands, the fast shock grows stronger, and the slow shock becomes weaker. Eventually, the slow shock diminishes, and the entire shock system evolves into a forward fast shock. copyrightAmerican Geophysical Union 1987

• Research Organization: Department of Mechanical Engineering, Catholic Univeristy of America, Washington, D. C.
• OSTI ID: 6401939
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A5; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
ATMOSPHERES
FLUID MECHANICS
GEOMETRY
HYDRODYNAMICS
HYDROMAGNETIC WAVES
MAGNETOHYDRODYNAMICS
MATHEMATICS
MECHANICS
PLASMA
SHOCK WAVES
SOLAR ACTIVITY
SOLAR CORONA
SOLAR WIND
STELLAR ATMOSPHERES
STELLAR CORONAE
VELOCITY