Development of a new significant wave height and dominant wave period parameterization scheme

Abstract

Ocean waves generally mix with wind waves and swell, of which only wind waves depend on the local wind field. Using 15 years of hourly observational wind-wave data from eight buoys off the northwest coast of the United States (US), the authors develop a new significant wave height (Hs) and dominant wave period (Tp) scheme (termed as WHP) for open oceans. This scheme relies only on the properties that a single atmospheric model can provide:Hs=0.0143U102+0.9626,H*=0.0628T*3/2where U10 is the wind speed at a reference height of 10m, H* is the dimensionless wave height, and T* is the dimensionless wave period. This relation is fitted to U10 values between 4 and 25ms−1. Comparison results show that the WHP scheme gives an almost best performance in predicting Hs and Tp for the open oceans across different regions. In addition to wind speed, considering the influence of wind direction and stability of the air/sea boundary layer is necessary for wind-wave prediction in coastal areas. Data from the Coupled Boundary Layers and Air–Sea Transfer experiment in LOW winds (CBLAST-LOW) and coastal buoys demonstrate that the effects of the wind direction and stability on Hs and Tp are significant for shallow water; with an increase in water depth, such impacts gradually decrease. Parameterizations for coastal wind waves are also investigated in this paper in Eqs. (19)–(31).