Characteristics of polar ionospheric plasma density irregularities with multi-point measurements

The polar ionosphere is characterized by its highly dynamic nature, exhibiting plasma turbulence and density irregularities across a wide range of scales. In turbulence stud- ies, the energy transfer between the temporal and spatial scales (or wavenumber) is typically analyzed by studying a measured turbulent variable’s power spectral density or structure function. In the ionosphere, the spatiotemporal characteristics of turbu- lent plasma density fluctuations are not well understood yet. Previously, these have been measured in situ, using data from satellites or rockets that provide instantaneous measurements along the track. Time series of volumetric measurements are needed to obtain a complete description of the fluctuating fields and energy transfer between the scales. To an extent, incoherent scatter radars such as the AMISR radars and the upcoming EISCAT3D radar can provide such measurements. This study develops tools to characterize the statistical properties of ionospheric density fluctuations using multi-point measurements. We utilize data from the AMISR radars in Resolute Bay, Canada, and compute the spatial and temporal structure functions of ionospheric den- sity fluctuations under various conditions. By examining fluctuations associated with multiple polar patches, we gain insights into energy redistribution across spatial and temporal scales.