Evaluation of Effectiveness of Waves on Air-Sea Heat Fluxes

Abstract:

The subtropical regions of the northwestern Pacific Ocean are considered to be the hotspot of typhoons that cause multiple and serious disasters in the coastal regions of East Asia. To study the air-sea energy fluxes within the typhoon is crucial for better understanding the evolving dynamics of typhoons. In this light, two Metocean buoys were deployed by National Taiwan University (NTU) research group in the subtropical areas of the northwestern Pacific Ocean during the typhoon seasons since 2016. Both buoys successfully survived after several super typhoons passed them and thus obtained valuable datasets (Yang et al., 2019). The measured maximum of significant wave height, dominant wave period, and wind speed were about 10 m, 20 s, and 25 m/s, respectively. The variations of the ocean heat fluxes were dominated by the latent heat flux (Q_L) during the typhoon influencing periods. To evaluate the effectiveness of waves on Q_L, the in-situ wave data were used with the application of the latest version of Tropical Ocean-Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA-COARE) flux algorithm (COARE 3.6). The estimated Q_L suggests that the averaged Q_L increases about 10% compared with those if the typhoon waves are not considered and could be greater than 30% during the typhoon periods. This means that the wave influence is one of the significant contributors for Q_L. The characteristics of Q_L during each recorded typhoon since 2018 will be presented.