Radar and Electromagnetic Ducting in Stable Atmosphere over Water (REDSAW)

Predicting evaporation duct in the stable boundary layer has been problematic as demonstrated by the discrepancies between the measured and calculated propagation loss. In particular, a limited number of modified refractive index (MRI) vertical profiles (dM/dz) observations exist when the lower atmosphere has stable thermal stratification. The evaporation duct heights calculated from the profiles in stable stratification deviate significantly when compared to those predicted by the Monin-Obukhov similarity theory (MOST). Preliminary analyses of the MRI profiles have also shown significantly different vertical structure for the thermally stable and unstable cases. These previous studies provide the motivation for focused efforts on examining the refractivity characteristics for when the surface layer is stable.