Variations of interplanetary fluctuations across the bow shock

Snell's transmission model of an MHD wave through a fast shock is not to treat transmission of waves beyond the critical incident angles. Considering that interplanetary fluctuations impinge on the bow shock from all directions, a model studying the interaction between MHD waves and the Earth's bow shock under ordinary conditions is presented in this paper. The results show that the state of fluctuations undergoes a significant jump across the Earth's bow shock. Asymmetry is higher in the northern hemisphere than in the southern hemisphere. This asymmetry of fluctuation activities in the magnetosheath region could be one of the causes for some asymmetrical phenomena in the magnetosphere. The results obtained in this paper are coincident with observations available.