Statistical Analysis of Refractive and Diffractive Scintillation at High Latitudes

Abstract

AbstractA comprehensive statistical analysis was performed on Global Positioning System scintillation data acquired at high latitudes from 2014 to 2017 after separating phase scintillation events originating from refraction and/or diffraction. Events exceeding a prescribed threshold were identified and analyzed statistically as a function of time, latitude, and propagation angle. The statistical analysis indicates that at high latitudes phase scintillation, which occurs more frequently than amplitude scintillation, is generated through refractive processes which can typically be treated as a stochastic Total Electron Content effect at high latitudes for Global Navigation Satellite System frequencies, and have the highest probability around magnetic noon in the Cusp. On average the phase scintillation index values decrease as a function of latitude, particularly during the first 6 hr of the evening. In addition, irregularities on the poleward side of the aurora are predominantly smaller than the Fresnel scale, when amplitude scintillation events are observed. By comparison, the mean of the phase scintillations on the equatorial side of the aurora, when amplitude scintillations are also present, indicates the existence of irregularities which are larger and smaller than the Fresnel scale. We also found that, during the day and at dusk, the spectral content of the irregularities apparently changes with decreasing off‐B Angle. No such increase is readily apparent at night or at dawn.