Meteotsunami Observation by WERA Ocean Radar Systems at the Dutch Coast

On 29 May 2017 a meteorological tsunami (meteotsunami) was generated in the North Sea due to an air pressure disruption, which reached the southwestern coastal area of the Netherlands. There are two operational WERA (R) ocean radar systems installed at the Dutch coast, which provide the sea current information around the entrance of the port of Rotterdam. After re-processing the acquired raw radar measurements from both systems using the original WERA tsunami detection software, specific sea current signatures generated by the moving meteotsunami wave were identified up to 40 km offshore. The results show good synchronization in tsunami detection both for radar systems and available tide gauge measurements. The detection of the tsunami-induced currents has shown a good applicability of phased-array radar technology for offshore tsunami monitoring and navigation safety. In Europe, the ocean radar systems are not yet used for tsunami alerting; although the systems can be easily upgraded by modifying the radar hardware and installing a tsunami detection software package. The presented results using the ocean radar systems show that offshore current measurements are feasible to be a useful complement to the already existing water level measurement network.