Avulsion in the Lightning River: Another Look at M-Components in the Context of a Laboratory Arc

This study is concerned with an instability in DC arc channels that is analogous to a process called `avulsion' in river channels and which accordingly, is given the same name. The instability involves both an abrupt brightening of the arc channel and a straightening of its tortuosity. The evidence in the literature for this instability in the continuing current of lightning serves as motivation to suggest it as a mechanism for the M-component that is still poorly understood.