Spatiotemporal Changes of Ocean Wave Height in Bohai, Yellow and East China Seas During 2004—2022

Based on buoy observation data, the wave simulation capability of the third generation wave model WAVEWATCH Ⅲ (WW3) with different drag coefficient parameterization schemes is verified. On this basis, WW3 is applied to calculate the wave height characteristics of the Bohai, Yellow and East China Seas from 2004 to 2022. Overall, the wave height variability is dominated by seasonal variations, with higher significant wave heights observed during autumn and winter compared to spring and summer. At the seasonal scale, the main months of maximum and minimum values of significant wave height at each grid point are identified. The coefficient of variation of the annual mean time series of the significant wave height in the Yellow Sea exceeds 4.5%, indicating a relatively strong interannual variability compared to the Bohai and East China Seas. At the interannual scale, significant wave height is correlated with wind speed, and there is significant negative correlations between the two and El Niño events in the Yellow Sea and East China Sea. The areas with the strongest negative correlation are all located in the Taiwan Strait, with the highest correlation coefficients reaching-0.77 and-0.72, respectively. Conversely, a weaker positive correlation is observed in the northern Bohai Sea region. Furthermore, the spatial distribution of the long-term trends of wave height is analyzed, revealing a pronounced negative trend in significant wave height in the waters east of Taiwan Island due to a significant decrease in the intensity of summer winds, with an intensity of more than 0.006 m/year.