Motion of aurorae



[1] Using high resolution auroral imagery and particle measurements from the Reimei spacecraft we distinguish ‘Alfvénic’ and ‘quasi-static’ auroral forms and implement a new multi-scale wavelet analysis technique to examine how the vorticity in these forms varies as a function of scale transverse to the geomagnetic field. We find from this analysis that the complex motions of aurorae can be described by power-laws relating spatial scale to optical vorticity. We demonstrate how these relationships naturally arise from the ‘conductance’ of geomagnetic field-lines and the physics of Alfvén waves.