Kurtosis Tensor as a Diagnostic of Particle Acceleration in the Bow Shock and Magnetopause

Kurtosis, the fourth order velocity moment, can be contracted into a rank-2 tensor that is used to quantify the overpopulation of suprathermal particles in a particular spatial direction. This makes it a convenient diagnostic tool for surveying sharp transitions in space, such as shock and reconnection layers, that are candidate mechanisms for local particle acceleration and have properties that are direction-dependent. This poster will discuss what sort of changes in kurtosis constitute particle acceleration for accelerating potentials that may or may not be dependent on energy and direction. Kurtosis profiles across the earth's bow shock and magnetopause will be presented and compared to analytic models, highlighting differences in kurtosis parallel and perpendicular to the magnetic field.