Gravitational instability of a layer of finite thickness and of infinite extension in relative motion with surrounding non-conducting material in the presence of magnetic field and rotation. (English) Zbl 0204.29202

The author analyzes the gravitational instability of an infinitely conducting fluid layer of finite thickness but of infinite lateral extent in the presence of uniform magnetic field and rotation. The layer is surrounded by a non-conducting material and these two media move with different velocities parallel to themselves. It is no wonder, therefore, that the author discovers instability in such a flow, which is akin to Kelvin-Helmholtz instability. The fact that the horizontal magnetic field exerts a strong stabilizing influence on the flow is also well-understood and exists in the literature. The response of the layer to both symmetric and asymmetric perturbations is discussed in detail.


76E20 Stability and instability of geophysical and astrophysical flows