Ocean response caused by typhoon and eddy interaction: a case study of tropical storm Molave(2009)

• Main Authors: Shin-Yi Liu, 劉欣怡
• Other Authors: 唐存勇
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/11074135656191023262

碩士 === 臺灣大學 === 海洋研究所 === 98 === The northwestern Pacific Ocean is the region where the tropical cyclone with strong intensity occurs most frequently. Previous studies showed that the oceanic pre-condition plays an important role on the characteristics of tropical cyclones. However, the mechanism still remains unclear due to lacking long-term oceanic observations. Three ATLAS buoys were deployed at northwestern Pacific Ocean to monitor atmospheric conditions and sea water temperature in the upper ocean. The intention is to study the air-sea interactions when typhoon passes by. In this study, a tropical cyclone (Molave) event was selected to investigate the variation of thermal structure of the upper ocean and air-sea inter-actions at the period during and after typhoon passed by. The results showed that, at time 2-4 hours late when Molave was closest to the observational platform, the air-sea temperature difference can reach to 3oC, the wind speed increased to 23 m/s, the solar short-wave radiation lost 15 W/m^2, the sensible heat lost 80 W/m^2, the latent heat flux lost 450 W/m^2, net heat flux decreased to -600 W/m^2 and mixed layer depth increased to 40m. The net heat flux recovered its quantity at 1-2 days later after Molave, but the latent hear and heat content still lost energy from ocean. The mixed layer depth was deepening to 65m. After 2-3 days later, the thermal structure of the upper ocean was re-built but the mixed layer depth still remained at 65 m. The eddy in the open ocean also plays a role on the storm. In this case, the warm eddy provided heat energy for Molave about 10^7 J/m^2, and by the sea level anomalies from satellite observation showed the warm eddy are slightly weakening.