Observations of Field-Aligned Currents and Their Role in Auroral Formation

Sammanfattning: Experimentally, it has been difficult to identify the exact physical processes atwork in the magnetosphere that drive the strong currents that later give rise to auroras. Theaim of this report has been to address this question by analyzing data gathered from Cluster-,MMS-, and DMSP satellite missions. The focus has specifically been on finding timeintervals between the years 2018 and 2023 where Cluster and MMS had magnetic field-lineconjunctions that occurred within the plasma sheet. Multiple conjunctions were found, and themost promising event, occurring on 2018-06-24, was further investigated. The field-alignedcurrent was calculated using the curlometer method. The current parallel to the magnetic fieldwas related to the shear velocity of the magnetic field and the ion bulk velocity. Theexperimental findings of this report confirmed the theoretical framework regarding thegeneration of field-aligned currents. In addition, during the investigated time interval, auroralkilometric radiation was observed while DMSP registered auroral acitivity. In conclusion, ithas been shown that there is an experimental connection between field-aligned currents andauroral formation.