First Coincident Radar and Optical Observations of a Meteor Radio Afterglow

It has been hypothesized that Meteor Radio Afterglows (MRAs) occur due to resonant transition radiation (RTR) where suprathermal electrons emit as they pass through electron density inhomogeneities in a turbulent plasma. Meteor trails are thought to produce suprathermal electrons through anion oxidation, which can be identified through meteor persistent trains. Meteor plasma turbulence can be identified through a non‐specular echo from a meteor radar. We present the first radar observations of a MRA that was also observed to produce a non‐specular echo and a persistent train, which indicate the presence of both plasma turbulence and anion oxidation. The observations were made using the Long Wavelength Array station at Sevilleta (LWA‐SV) and the Spread spectrum Interferometric Multi‐static Meteor radar Observing Network in New Mexico (SIMONe‐NM), the Widefield Persistent Train Camera version 2 (WiPT2) and the Global Meteor Network (GMN). Analysis reveals that while the MRA was spatially coincident a range‐spread, non‐specular echo, the brightest MRA emission came from a portion of the trail 8 km higher than the brightest radar scatter. We find that changes in the mean free path and collision frequency may be responsible for the higher altitude emission despite weaker plasma turbulence there. We also present evidence from the SIMONe‐NM head echo that the MRA and non‐specular echo were coincident with fragmentation of the meteoroid, which may have some role to play in both phenomena.