RADARNET-SUR FIRST WEATHER RADAR NETWORK IN TROPICAL HIGH MOUNTAINS

Abstract

eather radar networks are indispensable tools for forecasting and disaster prevention in industrialized countries. However, they are far less common in countries of South America, which frequently suffer from an underdeveloped network of meteorological stations. To address this problem in southern Ecuador, this article presents a novel radar network using cost-effective single-polarization X-band technology, the RadarNet-Sur. The RadarNet-Sur network is based on three scanning X-band weather radar units that cover approx. 87000km2 of southern Ecuador. Several instruments, including 5 optical disdrometers and 2 vertically aligned K-band Doppler radar profilers, are used to properly (inter-) calibrate the radars. Radar signal processing is a major issue in the high mountains of Ecuador because cost-effective radar technologies typically lack of Doppler capabilities. Thus, special procedures were developed for clutter detection and beam blockage correction by integrating ground-based and satellite-borne measurements. To demonstrate practical applications, a map of areas frequently affected by intense rainfall is presented, based on a time series of one radar which has been in operation since 2002. Such information is of vital importance for e.g. infrastructure management because rain-driven landslides are a major issue for road maintenance and safety throughout Ecuador. The presented case study of exceptionally strong rain events during the recent El Niño in March 2015 highlights the system?s practicality in weather forecasting related to disaster management. For the first time, RadarNet-Sur warrants a spatial-explicit observation of El Niño-related heavy precipitation in a transect from the coast to the highlands in a spatial resolution of 500 m.