PHARA (PHased Array Radar for Atmospheric research) – designing the next generation of high-resolution weather radars for urban meteorology and hydrology

As the hydrological cycle is accelerating due to climate change, metropolitan areas around the world are experiencing more intense rain storms ever more frequently and suffer from the floods they produce and their consequences for people and infrastructure. If we want to improve our capability to provide early warnings of heavy rainfall and flooding, we need to increase our understanding of the meteorological and hydrological processes leading to such events. High-resolution observations of clouds and precipitation systems are crucial in this respect. Here, we report on the first phase of an ambitious project to develop a novel phased-array radar for atmospheric research (PHARA), which aims to revolutionize cloud and precipitation research and ultimately support the development of the next generation of operational weather radars. PHARA will be a rapidly scanning phased-array Ku-band radar with polarization diversity, able to track cloud volumes continuously and observe microphysical processes directly, with a minimum of assumptions. PHARA will bridge the gap between traditional operational weather radars employed by national meteorological services and cloud profilers used by research institutes. It will be installed on a transportable platform, allowing measurements at various locations. Supplementing the radar facilities of the Ruisdael Observatory, the new radar will be the first of its kind, with an impact not just on the atmospheric sciences, but also on weather forecasting, extreme weather warnings, electromagnetic wave-based sensing, hydrology and water management. Finally, the PHARA team intends to initiate activities to exploit the radar for multiple complementary functions, from airport surveillance for wind shear and air traffic control, wind turbines and road traffic management, monitoring birds and sea-life, to climate-smart city planning and water management, serving many research communities at the same time.