On Plasma Instabilities in the Polar Cap Ionosphere

Plasma instabilities in the polar ionosphere cause the otherwise uniform plasma to develop inhomogeneous magnetic field-aligned structures over scale sizes from tens of km to meters. Radio waves propagating through these irregularities will experience strong scintillation, which disrupts VHF, UHF and GNSS navigation systems. At longer wavelengths (HF and VHF) the same plasma irregularities will also backscatter radio waves. In this presentation we describe efforts that are currently ongoing at Svalbard to study both the cause and effect of these irregularities. We present data from EISCAT, SuperDARN, ground-based optics, and in-situ sounding rockets. We also present initial results from a new receiver network that we are installing around Svalbard to monitor the impact on GNSS navigation systems.