Radar Research on the Atmospheric Boundary Layer

Abstract

The early literature in radar meteorology often refers to returns from the (apparently) clear boundary layer and lower troposphere as “ghosts” and “angels.” One of the “most authentic cases of this type” (Kerr, 1951) was reported by Major J.O. Fletcher in 1943. Excellent summaries of such reports were provided by Plank (1956) and Atlas (1959). It now seems clear that many such reports were due to backscatter from insects or birds and from the earth or sea surface once-reflected by an atmospheric layer. Modern high resolution radars demonstrate that echoes from both biological and particulate targets as well as from refractive index irregularities can contribute to clear-air backscatter in a way that is inseparable by operational radars (e. g., Richter and Jensen, 1973; Richter et al., 1974). In fact, the powerful Doppler radars of the NEXRAD system will be able to acquire valuable clear-air information on the prestorm environment during the warm months by using insects and sometimes refractive index irregularities as air-motion tracers.