Application of hourly ocean color satellite imagery on the sea surface transportation off Northeastern Taiwan influenced by typhoons

Abstract

The Kuroshio at the ocean of northeastern Taiwan is influenced by the complex seafloor topography As the Kuroshio crosses through the I-lan ridge to the Okinawa trough northly a part of tributary intrudes into the continental shed of East China Sea from the deep ocean and therefore forms an upwelling current with colder temperature and richer nutrients There is an interactive relation among the upwelling current the nearby Taiwan strait northward output flow and the Kuroshio so the cold eddy or cold dome easily formats nearby the upwelling current region During summer and autumn the typhoons usually pass through Taiwan and around ocean As they pass by the cold eddy or cold dome structure and the nearby sea surface current flow will be impacted by them Different typhoon paths will cause different impact in the same specific region The previous studies concern much on the cases which their paths pass the central or north part of Taiwan island The study of other path types of typhoon events is limited In this research we apply the image matching technique to the hourly ocean color images aquired by the geostationary satellite After calculating the flow field we discuss its relationship with the sea surface temperature and the seafloor topography We find out that the impact of typhoon passes through the northern ocean to the northeastern Taiwan ocean upwelling current is stronger than the cases pass through southern Taiwan Besides we also observe that there is a higher chance to observe a converge flow at the seafloor 200 meter depth it suggests that there is an 3-D flow cycle structure

Date of Award	2020
Original language	English
Supervisor	Cheng-Chien Liu (Supervisor)