Determination of magnetohydrodynamic shock normals

A method for determining many new magnetohydrodynamic shock normal expressions is described that uses both magnetic-field and plasma-flow parameters. These shock normal expressions are useful as a check on the usual magnetic coplanarity expression or for cases in which the most reliable data are mixed. For high Alfven Mach numbers, the exact results are well approximated by the simple velocity coplanarity formula. This is illustrated by calculating shock normals for the 1965 bow shock crossing of Pioneer 6.