南海东沙岛北部第二模态内孤立波特性研究

Study on the Characteristics of the Second Mode Internal Solitary Wave in the North of Dongsha Island of the South China Sea

高分一号是中国自主发射的光学遥感卫星,空间分辨率达到2、8和16 m,因此可以为尺度较小的第二模态内孤立波研究提供强有力的数据支撑。本文基于2014—2020年共7年高分一号光学遥感图像研究了南海东沙岛北部第二模态内孤立波特性,研究结果表明:在海水层结不变,海域第二模态内孤立波的光学遥感图像条纹亮暗次序与第一模态内孤立波的相反;第二模态内孤立波的波峰线远短于第一模态内孤立波的波峰线;南海东沙岛北部第二模态内孤立波在夏季被光学遥感观测到的概率最大;绝大部分第二模态内孤立波尾随在第一模态内孤立波之后,可能是第一模态内孤立波与地形凸起相互作用而产生了第二模态内孤立波。这一研究结果对于进一步研究全球海域第二模态内孤立波的特性奠定了良好基础。

The Gaofen-1 satellite is an optical remote sensing satellite independently launched by China with spatial resolutions of 2,8 and 16 m.Thus,it can provide strong data support for the study of the smaller second mode internal solitary waves.The characteristics of the second mode internal solitary wave in the South China Sea are studied based on the optical remote sensing images of Gaofen-1 from 2014 to 2020 in this paper.The research results show that in the sea area with invariable seawater stratification,the bright and dark orders of the second mode internal solitary waves of optical remote sensing images are opposite to those of the first mode internal solitary waves.The crest line of the second mode internal solitary waves is much shorter than that of the first mode internal solitary waves.The second mode internal solitary waves in the northern part of Dongsha Island in the South China Sea is the most likely to be observed in summer.Most of the second mode internal solitary waves occur after the first mode internal solitary waves,so it can be inferred that the second mode internal solitary waves are generated from the interaction of the first mode internal solitary waves and the raised parts of the ground.These results provide a good foundation for the further study of characteristics of the global second mode solitary waves.