Stochastic growth of ion cyclotron and mirror waves in Earth's magnetosheath - art. no. 056408

Electromagnetic ion cyclotron and mirror waves in Earth's magnetosheath are bursty, have widely variable fields, and are unexpectedly persistent, prop erties difficult to reconcile with uniform secular growth. Here it is shown for specific periods that stochastic growth theory (SGT) quantitatively ac counts for the functional form of the wave statistics and qualitatively exp lains the wave properties. The wave statistics are inconsistent with unifor m secular growth or self-organized criticality, but nonlinear processes som etimes play a role at high fields. The results show SGT's relevance near ma rginal stability and suggest that it is widely relevant to space and astrop hysical plasmas.