Performance of WWIII in simulating the ratio of maximum to significant wave height

The performances of WWIII model in simulating the characteristics of Hmax/Hs in the China Sea, are analyzed based on extensive buoy observation and one-year forecast simulation. The spatial distribution of long-term average state and probability distribution patterns are examined. The analysis of observation reveals distinctive spatial characteristics in the long-term average Hmax/Hs. Inland seas such as Bohai Sea and Beibu Gulf record the highest Hmax/Hs, while the open East and South China Sea record the lowest values. These characteristics are supported by three extreme models. WWIII performs well in simulating Hmax, and outperforms Boccotti (2000) and Alkhlidi and tayfun (2013) models in simulating Hmax/Hs in the China Sea. The long-term average Hmax/Hs from WWIII simulations align with observations and effectively capture the aforementioned spatial characteristics. They highlight the effectiveness of WWIII for operational wave forecasting in the China Sea. However, the probability distribution patterns of Hmax/Hs by WWIII differs greatly from observations. The distributions produced by WWIII are more concentrated than those observed, with lower accuracy as Hmax/Hs deviates from the peak value of the distribution. Additionally, WWIII fails to exhibit the bimodal or triple-peak pattern observed in the Bohai Sea, Yellow Sea, and Beibu Gulf. In the East and South China Sea, although WWIII reproduces the left skewed distribution from observations, but the degree of left skewness is pronounced. These discrepancies suggest areas for improvement, enhancing understanding of WWIII's reliability and limitations in complex oceanic conditions.