Oblique propagation of nonlinear magnetosonic waves

We consider obliquely propagating (with respect to the ambient field) nonlinear magnetosonic waves in a hot plasma with arbitrary beta. It is shown that the two-dimensional propagation of both the fast and the slow modes is governed by the Kadomstev-Petiashvilli soliton equation. Explicit expressions are obtained for the various physical quantities involved via the soliton solution.