The evolution of large-amplitude MHD waves near quasi-parallel shocks in the solar windWe discuss attempts to explain the steepening of magnetohydrodynamic waves upstream of the Earth's bow shock and the formation of short-wavelength 'shocklets' in terms of simple analytic models. The effort involves use of the Derivative Nonlinear Schroedinger Equation (DNLS) to describe the wave evolution. We review shortcomings of previous attempts to model foreshock wave phenomena in terms of wave packet evolution according to the DNLS. It is pointed out that: (1) the oblique propagation of the waves and (2) their growth by unstable particle distribution are conducive to the processes of wave steepening and shocklet formation. Numerical solutions of the DNLS with initial conditions corresponding to envelope-modulated, obliquely propagating wave packets yield evolved wave packets with many properties similar to the observed waves.
Document ID
19930049665
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Spangler, S. R. (Iowa Univ. Iowa City, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1992
Publication Information
Publication: In: Solar Wind Seven; Proceedings of the 3rd COSPAR Colloquium, Goslar, Germany, Sept. 16-20, 1991 (A93-33554 13-92)