Wind and Wave Climatic Characteristics and Extreme Parameters in the Bohai Sea

The Weather Research and Forecasting (WRF) model is employed to conduct numerical simulations and simulated acquisition of a 30-year (1993–2022) wind field dataset for the Bohai Sea. The simulated WRF wind field is subsequently used to drive the Simulating Waves Nearshore (SWAN) model, producing a corresponding wave field dataset for the same period in the Bohai Sea. Using these datasets, we analyzed the extreme value distributions of wind speed and significant wave height in the study area. The results reveal that both the annual mean wind speed and significant wave height exhibit a ring-like spatial pattern. The highest values are concentrated in the southern Liaodong Bay to the central Bohai Sea region, with a gradual radial decrease toward the periphery. Specifically, values decline from the center outward, from southeast to northwest, and from offshore to nearshore regions. The Gumbel extreme value distribution is applied to estimate 100-year return period extremes, yielding maximum wind speeds of 37 m/s and significant wave heights of 6 m in offshore areas. In nearshore regions, the 100-year return period wind speeds range between 20–25 m/s, while significant wave heights vary from 2 to 3 m. This study provides important scientific basis and decision-making reference for the design of offshore extreme conditions.