Propagation of Alfvén waves in shear flows: perturbation method for driven fluctuations

The nature of driven longitudinal velocity fluctuations and density fluctuations is studied when there is an Alfven wave propagating in the medium characterized by an inhomogeneous velocity. In this work, we introduce the perturbation method and obtain formal solutions for the driven compressible fluctuations. This perturbation procedure which introduces ordering in the wave solution can also be used in non‐ideal MHD cases. In the summary, it is discussed where this process can be important.