Turbulence in the terrestrial magnetosheath: Space–time correlation using the Magnetospheric Multiscale mission

Abstract

This research examines chaotic behavior of magnetic field fluctuations within turbulent collisionless plasma, as observed by spacecraft in the geospace environment. A key challenge lies in disentangling spatial and temporal variations; spacecraft measurements struggle to differentiate whether observed changes are due to spatial decorrelation or due to intrinsic time evolution; this introduces fundamental uncertainty in data analysis. The study aims to determine what causes time-decorrelation between spatial points in the turbulent magnetosheath magnetic field: Is it rapid sweeping of spatial structure or strong local nonlinear interactions? Understanding these mechanisms is crucial for predicting how correlations persist in space-time. While similar problems are well studied in hydrodynamics and magnetohydrodynamics, this fundamental problem remains largely unexplored in space plasma observation.