High kinetic energy jets in the Earth's magnetosheath: Implications for plasma dynamics and anomalous transport

High kinetic energy density jets in the magnetosheath near the Earth magnetopause were observed by Interball-1 [1]. In this paper we continue the investigation of this important physical phenomenon. New data provided by Cluster show that the magnetosheath kinetic energy density during more than one hour exhibits an average level and a series of peaks far exceeding the kinetic energy density in the undisturbed solar wind. This is a surprising finding because in equilibrium the kinetic energy of upstream solar wind should be significantly diminished downstream in the magnetosheath due to plasma braking and thermalization at the bow shock. We suggest to resolve the energy conservation problem by the fact that the non-equilibrium jets appear to be locally superimposed on the background equilibrium magnetosheath, and thus the energy balance should be settled globally on the spatial scales of the entire dayside magnetosheath. We show that both the Cluster and Interball jets are accompanied by plasma super-diffusion and suggest that they are important for energy dissipation and plasma transport. The character of the jet- related turbulence strongly differs from that of known standard cascade models. We infer that these jets may represent the phenomenon of general physical occurrence observed in other natural systems, like heliosphere, astrophysical and fusion plasmas [2 – 10].