Meteorological and Astronomical Influences on Radar Reflectivity in the Convective Boundary Layer

Abstract

Observations are presented of time-varying radar reflectivity during a partial solar eclipse in Oklahoma. The measurements from a radar of 10-cm wavelength, were obtained in the clear-air boundary layer. The reflectivity changes closely follow the variation in solar radiation associated with the eclipse. Possible mechanisms for the change in reflectivity are reviewed, in particular the effect of surface fluxes of heat and mositure. A formula is derived that relates radar reflectivity to surface fluxes of sensible and latent heat. Other evidence of a relationship between these fluxes and sensible and latent heat. Other evidence of a relationship between these fluxes and radar reflectivity is presented, namely the effect of local cloud cover on reduced insolation and variations in surface wetness.