Simultaneous observations of ducted Pc1 waves at multi-stations in Antarctica

Abstract

Electromagnetic ion cyclotron (EMIC) waves generated in the equatorial plane, propagate from the magnetosphere to the ionosphere along field lines and convert to compressional waves by mode-conversion. Such propagated waves are observed in the Pc1 band (0.2-5 Hz) on the ground and horizontally propagate through the maximum electron density region in the ionosphere. Korea Polar Research Institute has been operated the array of search-coil magnetometers with identical system at Jang Bogo Station, (JBS, -74.4° geographic latitude, 164.1° geographic longitude), Neumayer (VNA, -70.4° geographic latitude, -8.2° geographic longitude), and King Sejong Station (KSS, -62.1° geographic latitude, -58.5° geographic longitude). We statistically examined the spectral features of Pc1 waves simultaneously identified at JBS, VNA, and KSS. It is found that the amplitude of Pc1 waves rapidly reduced as they propagate to lower latitude than higher latitude. We also confirmed the Pc1 waves in the ionosphere when Swarm spacecraft pass over near VNA. We found that the frequency of Pc1 waves at Swarm slightly higher than those on the ground. We suggested that this difference of frequency due to Doppler effect at Swarm.