Examining Turbulence in the Plasma Sheet and its Role in Transport

Abstract:

In this study the nature and implications of turbulence in the plasma sheet is explored with emphasis on large scale and meso-scale processes. The relationship between turbulence and reconnection, and its contribution to magnetospheric transport and dynamics will be evaluated. Observational studies to date have shown that the magnetotail rarely exhibits simple steady convection; instead, flows in the magnetotail have a high level of fluctuations. Flows driven on the scale of the entire system break up into structures that cascade to smaller scales finally reaching scales at which they are dissipated. MHD simulation studies have been carried out both for idealized cases which can be compared to statistical studies of observed events and for event studies where direct comparisons to observations have been made. . In both cases realistic fluctuation spectra were produced in the inertial range. The simulations also do a good job of representing the effects of dissipation and yield dissipative scale lengths that are comparable to those inferred from observations. Turbulence is important at intermediate scales in the plasma sheet, in particular around dipolarization fronts. We will explore the interaction between large-scale and smaller-scale fluctuations and their contributions to the magnetotail structure. We will use a global MHD simulation and iPIC3D implicit particle in cell simulation to examine how turbulence is related to global and local processes involved in the current sheet.