Summary
The ionosphere forms a comparatively dense layer of partially ionized gas around Earth. The ionosphere as a whole works to dissipate the energy provided by the constant connection it has to the solar wind and magnetosphere systems. This energy dissipation, which creates beautiful displays of aurora in Earth’s polar regions, is associated with plasma turbulence that is at once detrimental to key navigational technologies such as GPS, and radio communication in commercial air and ship traffic.
The primary way in which the energy is transferred into the ionosphere is for the field-aligned currents that flow into the ionosphere with the aurora to drive Joule heating. At the same time, energetic charged particles drive these currents, and their impact deposits charges and drives polarization electric fields.
As a result, turbulence in the ionosphere forms on a wide range of scales, but some scales are more important than others. This is caused by various instability processes’ preferential scale-sizes, but could also be caused by the shape of auroral precipitation patterns. In essence, auroral forms are caused by electric potential wells in the magnetosphere, and the walls of these wells drive Pedersen return currents that close the field-aligned currents in the aurora.
It is hypothesised the edge thickness of auroral energy beams constitutes a characteristic length-scale in auroral plasma turbulence. Traces of this thickness scale will be sought in the ESA data archive of near-Earth space observations, by examining various turbulent (and linear) signals in the space plasma in-situ, in particular, the novel ICEBEAR 3D dataset, which presents the radar aurora as a 3D point-cloud for the first time.
The proposed measurement platform can study detailed small-scale dynamics localized over Northern Saskatchewan, Canada, and large-scale observations performed in-situ by ESA satellites and others. The inclusion of several ground-based instruments (all-sky-imagers, the ICEBEAR coherent scatter radar) allows ionospheric bottom-side- and topside-dynamics to be taken into account simultaneously.
