Characterising the electron density fluctuations in the high-latitude ionosphere at Swarm altitude in response to the geomagnetic activity

The high-latitude ionosphere is characterised by plasma density irregularities with
typical lengths in a wide range of scales (from ~1 m up to ~1000 km). The enhancement
of these irregularities caused for instance by severe Space Weather conditions can affect
trans-ionospheric communications between ground facilities and satellites. For this
reason, an accurate characterisation of the dynamic properties of electron density and
their variation with the geomagnetic activity level is of particular interest for the Space
Weather especially at high latitudes. In this framework, taking advantage of high
resolution in situ measurements by the recent ESA-Swarm space mission orbiting in the
ionospheric F-layer, we study both the dynamical properties of the electron density and
the scaling properties of the electron density fluctuations at high latitudes in the
Northern and Southern Hemispheres in response to changes in the geomagnetic activity
levels via nonlinear techniques involving the first-order structure functions. Indeed, it
has been shown that the turbulent character of the ionospheric plasma density plays an
important role in the generation and dynamics of ionospheric plasma density
irregularities and the study of the scaling properties of the electron density fluctuations
permits us to characterise the possible turbulent state of the ionospheric electron
density. The obtained results are consistent with the turbulent character of the
ionospheric dynamics, and with the presence of different turbulent regimes that show a
dependence on the geomagnetic activity levels, magnetic latitude and MLT values.