Reflection and transmission of MHD waves in an inhomogeneous magnetosphere

MHD wave properties in inhomogeneous plasmas such as the magnetosphere are complicated by the existence of a local cutoff, coupling, and dissipations. We have developed a theoretical technique for calculating the reflection and the transmission of MHD waves in one-dimensional inhomogeneous plasmas by adopting the invariant imbedding method. This approach allows us to analytically estimate the exact reflection and transmission coefficients when MHD waves propagate through arbitrary nonuniform regions. The region of the Alfven speed crest is considered as an example and may approximate the plasmapause region. When the initial compressional MHD waves are assumed to propagate into that region, we show how reflection, transmission, and resonant absorption depend on frequencies and wavenumbers.