Magnetic Aspect Sensitivity of Nonspecular Meteor Trail Echoes

Abstract

The ablation of micrometeoroids entering Earth's atmosphere leaves behind a hot, dense column of plasma between 80 and 120 km altitude. Sharp density gradients can drive the plasma unstable, leading to turbulence and waves at the same altitude, which are often observed as coherent radar echoes. These echoes persist for 10s of milliseconds up to several minutes and are known as nonspecular trails. The turbulence from these trails is highly aspect sensitive and typically only observed within a few degrees of perpendicular to the magnetic field. In this letter, we present a new approach to measure the magnetic aspect sensitivity of nonspecular meteor trail echoes using the AMISR‐14 radar system. Using multiple beams, we simultaneously observe each trail at several different angles and directly observe aspect angle effects. Using this approach, we find that at 445 MHz, the observed power decays at 4.58 ± 0.46 dB/degree.