Kinetic Physics of Dipolarization Fronts: Theory, Simulation, Laboratory Experiments and in situ Observations

Dipolarization fronts (DFs) are fast Earthward propagating plasma structures with spatial gradients (in the frame moving with the front) of the order of the ion gyroradius or smaller. Broadband, mostly electrostatic, wavepower is observed at the front and complex nonlinear electromagnetic waves behind the front. DFs are thought to be formed in the magnetotail due to magnetic reconnection that depletes a flux-tube of plasma. This depleted flux-tube is buoyant and thus rushes towards the Earth. DFs are important for transporting particles and energy from the magnetotail into the inner magnetosphere.