Multi-wavelength impacts on coastal radar performance during a sea breeze

Abstract

Sea breeze circulations dramatically impact the detection performance of coastal radar and are forecast to increase in strength and frequency into the 21st century. Dry and warm air from the land flows offshore between 100 and 200 meters above sea level out to 100km offshore. This redistribution of water vapor and temperature creates strong vertical humidity and temperature gradients resulting in significant radar ducting. These thermodynamic gradients and resulting non-standard propagation structures vary in time and space as the sea breeze develops. Spatio-temporal radar skip zones develop within the ducts and reduced target detection ranges develop above the ducts. Notional S, C and X band radars are modeled with the Advanced Refractive Effects Prediction System and are located at the shoreline during a sea breeze. The azimuth and range dependent refractivity field is modeled by the Regional Atmospheric Mesoscale Prediction System.