Development of a new significant wave height and dominant wave period parameterization scheme. (1st May 2017) - Wang, Chendi
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 ( H s ) and dominant wave period ( T p ) scheme (termed as WHP) for open oceans. This scheme relies only on the properties that a single atmospheric model can provide: H s = 0.0143 U 10 2 + 0.9626, H * = 0.0628 T * 3 / 2 where U 10 is the wind speed at a reference height of 10 m, H * is the dimensionless wave height, and T * is the dimensionless wave period. This relation is fitted to U 10 values between 4 and 25 m s −1 . Comparison results show that the WHP scheme gives an almost best performance in predicting H s and T p 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 H s and T p 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) . Highlights: A new H s and T p scheme is developed that only relies on 10-m wind speeds for open ocean wind waves (termed WHP). A new H s and T p scheme is developed that relies on U 10, wind direction and Rb for coastal wind waves (termed CWHP). WHP and CWHP overall provide a better description of H s and T p for open ocean and coastal wind waves, respectively. They fulfill our requirement to consider the wind-wave effects in a single atmospheric model.