GPS phase scintillation and HF radar backscatter occurrence in the high-latitude ionosphere

Abstract

The Canadian High Arctic Ionospheric Network (CHAIN) of ten dual-frequency GPS receivers has been operating since 2008. One-minute amplitude and phase scintillation indices and total electron content (TEC) are computed from data sampled at 50 Hz. The climatology of GPS phase scintillation for 2008-2009 [1] is updated to include year 2010 as the solar activity gradually increases and more coronal mass ejections impact the geospace. As a function of magnetic local time and geomagnetic latitude, the phase scintillation predominantly occurs in the cusp and the nightside auroral oval. The auroral phase scintillation shows an expected semiannual oscillation with equinoctial maxima known to be associated with aurorae, while the cusp scintillation is dominated by an annual cycle maximizing in autumn-winter. Depletions of the mean TEC are identified with the statistical high-latitude and mid-latitude troughs. Scintillation-causing irregularities may coexist with small-scale field-aligned irregularities detected as HF radar backscatter. The occurrence climatology of phase scintillation and of the HF backscatter at high latitudes are compared.