Direct Evidence for Auroral Kilometric Radiation Propagation Into Radiation Belts Based on Arase Spacecraft and Van Allen Probe B

Recent studies have shown that auroral kilometric radiation (AKR) can propagate from the polar source cavity into equatorial belt but there is no direct evidence yet. By examining 19-month data Arase satellite and Van Allen Probes, we report a unique event distinct AKR emissions are observed simultaneously at high low latitudes, with peak wave spectra in frequency 300–400 kHz. Using three-dimensional ray tracing method, simulate paths three typical frequencies (220, 350, 550 kHz), show more for 350 kHz downward through locations of Probe B than those other two frequencies. This result successfully explain observation provides to latitude under suitable conditions.