Flow channel dynamics in the Magnetotail – Simulations and multi-spacecraft analyses from THEMIS observations

Abstract:

Although various multi-spacecraft missions have been launched in the past two decades little effort has been made to actually explore the potential of multipoint measurements in space plasmas. Consequently, analysis techniques for multi-spacecraft measurements are still rare and the integration of new methods into existing approaches is often done hesitantly. Still, in the context of magnetospheric missions like CLUSTER, THEMIS, and, most recently, MMS, the need for new methods exploiting all the possibilities of multipoint measurements is obvious.

The aim of this work is to explore the application of system analysis techniques to THEMIS observations in the Earth’s magnetotail. Therefore, magnetometer data of at least three spacecrafts is used to analyze the characteristics of the plasma sheet during pearl-on-a-string-like configurations of the probes. Earlier studies have modeled tail regions as a two-dimensional waveguide structure with the ability to duct wave trains within a slab geometry. From these results, and from the observational data, simple properties of the plasma sheet region will be derived. To account for the reliability of the observational results, the study is supported by two-dimensional ideal MHD simulations of waveguide structures.

The outcomes of this work are applicable to the time evolution and characterization of bursty bulk flows and traveling plasma bubbles in the magnetotail.