The turbulent momentum fluxes through the air-sea interface are usually measured by the eddy covariance method, in which the measurement plane must be parallel to the horizontal plane. In practice, it is impossible to exactly satisfy this requirement, thus tilt corrections are needed. Three tilt correction methods, including double rotation, triple rotation, and planar fit, have been proposed. This study comprehensively investigates the influence of tilt correction methods on the air-sea momentum flux by utilizing observational data from an offshore platform in the South China Sea. It is shown that the momentum flux corrected by the double rotation method is consistent with that from the planar fit method in the condition of neutral stratification of the atmosphere. In the condition of stable stratification, the planar fit method demonstrates the best adaptability. On the other hand, the triple rotation method is failed to further improve flux on the basis of the double rotation method. It is also indicated that the effects of various tilt correction methods can be neglected on the turbulent kinetic energy spectrum, wind stress direction, and the angle between wind stress direction and wind direction. The wind stress directions are on the left, consistent and scattered with the wind directions under stable, neutral, and unstable stratification of the atmosphere, respectively. However, the drag coefficient decreases under stable conditions. The relationship between the drag coefficient and wind speed from this study generally agrees with those of the previous studies.

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.