Study on the storm surges induced by cold waves in the Northern East China Sea

• Cold-wave winds have certain spatiotemporal distributions in the NECS.
• Responses of storm surge to wind direction, speed and duration are predictable.
• Coupled weather cold wave induces a larger magnitude and area of storm surge.
• Tide–surge interaction has a significant effect on the magnitude and phase of surge.

Cold wave, a kind of severe weather system, can bring strong wind and induce significant sea level rise to the Northern East China Sea. Based on CFSR data, the study shows the monthly distributions of invaded days and the spatiotemporal distributions of cold-wave wind direction and wind speed. A three-dimensional numerical model (ROMS) was developed to study storm surges induced by cold waves. The role of wind direction, wind speed, wind duration, extratropical cyclone and tide–surge interaction is investigated by conducting different sensitivity experiments. The results indicate that storm surges mainly happen at the coasts perpendicular to the wind directions. Surge range and time lag are related to the geometry of the basin and the continental shelf. The response of the sea-level fluctuations to cold wave indicates that there is a positive correlation between crests and wind speed, a negative correlation between troughs and wind speed, but no obvious correlations to wind duration. Coupled weather cold waves, which yield a larger range and a multi-peak structure of surges, can be classified according to cold wave tracks and extratropical cyclones. The tide–surge interaction has an obvious and different effect on the magnitudes and phases of storm surges for different tidal stages.