Development of Air-Sea Bulk Transfer Coefficients and Roughness Lengths in JMA Non-hydrostatic Model and Application in Prediction of an Intense Tropical Cyclone

摘要

References(18) Supplementary materials(1) A new parameterization scheme of air-sea momentum flux, heat flux and moisture flux is introduced into the Japan Meteorological Agency Non-Hydrostatic Model (JMA-NHM, Saito et al. 2006). The new formulation describes the saturation properties of bulk transfer coefficients of momentum, heat and moisture under high winds regime (> 30 m s-1). It also considers the effect of sea-wave drag in the roughness length. The proposed parameterization is applied to simulate an intense tropical cyclone Hagupit (0814). The impact of the new scheme on the tropical cyclone prediction is found in the increase of maximum surface wind speed and decrease of central pressure. Improvements in the forecasts of distribution of high wind areas and precipitation are obtained. This may help to improve the model predicted wind-pressure relationship for intense tropical cyclones.