Generation sites of internal solitary waves in the southern Taiwan Strait revealed by MODIS true-colour image observations

摘要

Based on 12 years (2000-2011) of Moderate Resolution Imaging Spectroradiometer (MODIS) true-colour images, statistical characteristics of internal solitary waves (ISWs) in the southern Taiwan Strait were studied. Two types of ISWs with a distinct scale of wave crest length and geographic distributions were identified: Type-Ⅰ waves have larger wave crest lengths and span a large area from the southern Taiwan Strait to the northern South China Sea, while Type-Ⅱ waves have smaller wave crest lengths and appear only at the southeastern corner of the Taiwan Strait. Further analyses based on an empirical model of ISW propagation and on the calculations of the depth-integrated internal tide-generating body force suggested that Type-Ⅰ waves mainly originate from the Luzon Strait, while Type-Ⅱ waves are locally generated at the shelf break in the southeastern corner of the Taiwan Strait.