Objective Tropopause Height Determination Using Use-Resolution VHF Radar Observations

Abstract

The magnitude of backscattered power observed at vertical incidence by a VHF radar is related to atmospheric stability in accordance with the Fresnel scattering model. Utilizing a modified Fresnel scattering model, we can determine tropopause height objectively from the observed vertical profile of backscattered power. The method is tested with observations of the Alpine Experiment (ALPEX; France), Platteville, Colorado and Poker Mat, Alaska radars taken since 1979. Using 750 m resolution the tropopause is found to be within a few hundred meters of the tropopause determined from nearly simultaneous radiosonde observations and using 2.2 km resolution the tropopause is found to be within about 600 m. Furthermore, radar-determined tropopause heights can be automatically scaled from existing records, or even routinely determined on-line.