Quasi two-dimensional nearly-incompressible solar wind fluctuations

We explore the possibility that solar wind fluctuations (apart from large-scale compressive structures and shock waves) constitute a nearly-incompressible quasi-two-dimensional MHD fluid consisting of both classical transverse Alfvenic fluctuations with wave vectors predominantly parallel to the mean magnetic field and quasi-two-dimensional fluctuations with wave vectors primarily transverse to both the mean field and the fluctuations. For this second group, the direction of minimum variance lies along the mean magnetic field, density fluctuations are small and anticorrelated with |B|, and pitch-angle scatterng of solar cosmic rays is suppressed. (author). 44 refs.; 1 fig