Abstract
We study the reflection and refraction of hydromagnetic waves under a uniform magnetic field and apply the results to the propagation of hydromagnetic waves of short period in the exosphere. In a meridian plane, an incident wave is reflected or refracted in the same type of waves. In the equatorial region, the transverse wave can not directly propagate into lower region from upper region, while the isotropic wave whose wave normal is perpendicular to the main field or is in a meridian plane can.
