Relationships Between the Typhoon-Induced Wind and Waves in the Northern South China Sea

Wind-wave interactions have been broadly investigated for their great implications on air-sea momentum transfer, whereas our knowledge on those forced by typhoons (hurricanes) is still limited. Accordingly, relationships between wind and wave characteristics were analyzed using observations on the northern South China Sea during four typhoons. An empirical wind-wave model was proposed for typhoon-induced wind seas which exhibits satisfactory skills in predicting significant wave heights (Hs). Meanwhile, typhoon-forced wind-wave relation was investigated using the wave growth function. By delineating the relationship between the dimensionless Hs and peak wave period scaled with 10 m and friction wind velocities, simplified functions for the growing and steady wind seas were proposed, respectively. However, great misalignment could occur owing to the contamination of swells resulting from the typhoon's slow translation speed, as well as the extremely short or long radial distance from typhoon centers, indicating the necessity of considering typhoon structures in screening swell influences.