( 2001. The American Astronomical Society. All rights reserved. Printed in U.S.A. RANDOM SCATTERING AND ANISOTROPIC TURBULENCE OF SHEAR WAVE PACKETSALFVE N

A theoretical model is given of anisotropic magnetohydrodynamic turbulence in the interstellar medium and the solar wind. The model is motivated by observations that show signiÐcant deviations from the Kolmogorov power law. Dimensional and heuristic arguments are given and critically assessed. On the basis of the weak turbulence approximation in which three-wave interactions dominate, analyti-cal and numerical results are obtained for the anisotropic energy spectrum produced by the random scattering of shear waves propagating parallel to a large-scale magnetic Ðeld. The energy spec-Alfve n trum is shown to be proportional to qualitatively consistent with some observations and wavek M ~2, kinetic theory. Subject headings: magnetic Ðelds È MHD È turbulence È waves 1