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Session 120 - The Sun.
Oral session, Saturday, January 10
International Ballroom East,

[120.06] Self-similar Time-dependent MHD in Three-dimensional Space

B. C. Low (High Altitude Observatory, NCAR), S. E. Gibson (NASA/GSFC)

A general class of self-similar exact solutions to the time-dependent ideal MHD equations was discovered in the early eighties (Low 1982 ApJ 254, 796; Low 1984 ApJ 281, 392). These solutions describe exploding or imploding atmospheres in the polytropic approximation with a 4/3 index and in the presence of Newtonian gravity. A full range of accelerating, decelerating, or inertial explosions or implosions are possible. A novel feature of these solutions is that they allow for full variation in three dimensional space unstricted by any spatial symmetry, presenting an opportunity for generating models of exploding or imploding atmospheres in realistic geometry. The reduction of the problem from four dimensional space-time to the three-dimensional similarity space leads to governing equations which are still highly non-trivial to solve. This paper presents the results of a method of solution which yields a three-dimensional, analytic model of a coronal mass ejection carrying a ball of twisted magnetic fields pushing its way through surrounding open magnetic fields in a time-dependent expulsion out of the solar corona (Gibson and Low 1998 ApJ, in press). This method may be useful in other astrophysical applications.

The National Center for Atmospheric Research is sponsored by the National Science Foundation.

The author(s) of this abstract have provided an email address for comments about the abstract: LOW@HAO.UCAR.EDU

Program listing for Saturday