Lightning observations with the Strato-Tropospheric UHF and VHF radars at Arecibo, Puerto Rico

Observations were carried out at National Astronomy and Ionospheric Center (NAIC) in Puerto Rico with a dual-frequency (46.8MHz/430MHz) Strato-Tropospheric radar associated with ground-based precipitation and electrostatic field measurements. This experimental set-up is devoted to provide wind measurements and detection of clear air turbulence. During a thunderstorm event, VHF-UHF radar receivers detected wide frequency band radiation emitted by lightning flashes. We present in this paper observations of a specific storm for which lightning radiation and ionized lightning channel were fortuitously and simultaneously detected. A bi-level structure of the lightning flash channel is observed and is consistent with observations obtained previously by other authors with VHF lightning mapper.