Pi1B propagation in the high-latitude ionosphere

Abstract

We present a statistical study of approximately 40 Pi1B events, using data gathered from an induction coil magnetometer array located in Svalbard, Norway, showing good alignment along the magnetic meridian: Hornsund (corrected geomagnetic (CG) latitude = 74.23° magnetic latitude (MLAT), magnetic local time (MLT) midnight = 21:01), Longyearbyen (CG latitude = 75.29° MLAT, MLT midnight = 20:50), and Ny lesund (CG latitude = 76.30° MLAT, MLT midnight = 20:56). We find that average attenuation across the 0.001-1.0 Hz bandwidth is in the range of 30-37 dB/1000 km but that attenuation is not independent of frequency. The nonlinear dependence of attenuation on frequency is most pronounced for sunlit events, and the complexity is expected to result from a mixing of ducted and direct Pi1B signals. Copyright 2012 by the American Geophysical Union.