Geophysical Research Letters
American Geophysical Union
A study of the reflection of Alfvén waves at a horizontally inhomogeneous ionosphere has been carried out. In this study, the Alfvén speed above the ionosphere is assumed to be uniform and the ionosphere is treated as a height‐integrated conducting slab. Analytical and numerical results indicate that the horizontal nonuniformity of the ionospheric conductivity can lead to a rotation of the reflected wave fields and cause field‐aligned currents that originate in the ionosphere. A strong conductivity nonuniformity in the direction perpendicular to the incident wave field, large Hall to Pedersen conductivity ratios, and low conductivity values lead to a large rotation of the reflected wave field in the range from a few to 40°. The implications of the theoretical results for some ionospheric phenomena are presented, including comments on the Harang discontinuity and Sun‐aligned arcs.
Zhu, L., J. J. Sojka, R. W. Schunk, and D. J. Crain (1993), Influence of horizontal inhomogeneity in the ionosphere on the reflection of Alfvén waves, Geophys. Res. Lett., 20(4), 313–316, doi:10.1029/93GL00079.