The velocity characteristics of internal solitary waves in the Andaman Sea by optical remote sensing
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摘要: 安达曼海内孤立波非常活跃且错综复杂，传播速度是内孤立波的重要特征参量，本文采用光学遥感手段建立了内孤立波传播速度的计算方法。收集并处理大量Terra/Aqua-MODIS遥感图像，利用两景图像追踪同一内孤立波与同一激发源产生的内孤立波波群两种方法定量研究安达曼海内孤立波传播速度。研究结果表明：安达曼海内孤立波传播速度在0.5～2.7 m/s之间，内孤立波传播方向主要受海底地形的影响，传播速度大小在传播过程中随水深变浅而呈减小的趋势，在深水区传播速度大小还呈现出季节性差异。Abstract: Internal solitary waves (ISWs) are widely distributed and have a large scale in the Andaman Sea. The velocity of ISWs is an important dynamic parameter. In this paper, approaches are proposed and demonstrated for calculating the propagation velocity of ISWs by optical remote sensing. The optical remote sensing data of MODIS in the Andaman Sea are collected and two methods are adopted to aquire velocity. One is to track the same ISWs based on two remote sensing satellites. The other is to find two or more packets of ISWs from the same generation in a single image. The overview of velocity distribution in the whole Andaman Sea is obtained by combining two methods. The results show that the propagation velocity of the Andaman Sea internal solitary wave ranges from 0.5 m/s to 2.7 m/s. The direction of the velocity is mainly influenced by the bottom topography, and the velocity decreases with the depth of water. In addition, different seasons correspond to different velocities in the deep water areas.
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Key words:
- internal solitary wave /
- optical remote sensing /
- Andaman Sea /
- semidiurnal tide
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图 2 安达曼海不同季节平均垂向温度（a）、盐度（b）、密度（c）及浮频率（d）曲线
Fig. 2 Averaged temperature (a), salinity (b), density (c) and buoyancy frequency (d) vertical profiles in different seasons in the Andaman Sea
图 3 2015—2017年MODIS图像统计获得的安达曼海内孤立波的空间分布
Fig. 3 Spatial distribution of internal solitary waves obtained by MODIS images from 2015 to 2017 in the Andaman Sea
图 4 追踪法计算内孤立波传播速度示意图
a为2017年3月13日04:00 UTC的MODIS图像，b为2017年3月 13日07:00 UTC的MODIS图像
Fig. 4 Schematic diagram for calculating the propagation velocity of internal solitary waves by tracing method
MODIS images acquired at 04:00 UTC (a) and 07:00 UTC (b) on March 13, 2017
图 5 潮周期法计算内孤立波传播速度示意图
图为2018年3月3日04:30UTC的MODIS图像
Fig. 5 Schematic diagram for calculating the propagation velocity of internal solitary waves by tidal period method
The MODIS image acquired at 04:30 UTC on March 3, 2018
图 6 图像追踪法获得内孤立波传播速度矢量图
Fig. 6 Velocity vector of internal solitary waves aquired by image tracing method
图 7 利用半日潮周期计算的内孤立波平均传播速度矢量
Fig. 7 Velocity vector of internal solitary waves aquired by tide method
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[1] Maury M F. The Physical Geography of the Sea and its Meteorology[M]. New York: Harper, 1861: 404−405. [2] Perry B R, Schimke G R. Large-amplitude internal waves observed off the northwest coast of Sumatra[J]. Journal of Geophysical Research, 1965, 70(10): 2319−2324. doi: 10.1029/JZ070i010p02319 [3] Osborne A R, Burch T L. Internal solitons in the Andaman Sea[J]. Science, 1980, 208(4443): 451−460. doi: 10.1126/science.208.4443.451 [4] Hyder P, Jeans D R G, Cauquil E, et al. Observations and predictability of internal solitons in the northern Andaman Sea[J]. Applied Ocean Research, 2005, 27(1): 1−11. doi: 10.1016/j.apor.2005.07.001 [5] 谢志宏. 利用SAR及MODIS卫星影像研究安达曼海非线性内波之发源及演变[D]. 基隆: 台湾海洋大学, 2004: 26–39.Xie Zhihong. A study of generation and evolution of nonlinear internal waves in the Andaman Sea by using SAR and MODIS images[D]. Keelung: National Taiwan Ocean University, 2004: 26–39. [6] Alpers W, Heng Wangchen, Hock L. Observation of internal waves in the Andaman Sea by ERS SAR[C]//IGARSS'97. 1997 IEEE International Geoscience and Remote Sensing Symposium Proceedings. Remote Sensing-A Scientific Vision for Sustainable Development. Singapore: IEEE, 1997. [7] Vlasenko V, Alpers W. Generation of secondary internal waves by the interaction of an internal solitary wave with an underwater bank[J]. Journal of Geophysical Research Oceans, 2005, 110(C2): 1105−1107. [8] Silva J C B D, Magalhaes J M. Internal solitons in the Andaman Sea: a new look at an old problem[C]//Proceedings Volume 9999, Remote Sensing of the Ocean, Sea Ice, Coastal Waters, and Large Water Regions. Edinburgh, United Kingdom: SPIE Remote Sensing, 2016: 999907. [9] Li Yineng, Peng Shiqiu, Zeng Xuezhi. Observations and simulations of the circulation and mixing around the Andaman-Nicobar submarine ridge[J]. Atmospheric and Oceanic Science Letters, 2012, 5(4): 319−323. doi: 10.1080/16742834.2012.11447008 [10] Zhou Liying, Yang Jingsong, Wang Juan, et al. Spatio-temporal distribution of internal waves in the Andaman Sea based on satellite remote sensing[C]//Proceedings of the 9th International Congress on Image and Signal Processing, Biomedical Engineering and Informatics. Datong, China: IEEE, 2017: 624−628. [11] Porter D L, Thompson D R. Continental shelf parameters inferred from SAR internal wave observations[J]. Journal of Atmospheric and Oceanic Technology, 1999, 16(4): 475−487. doi: 10.1175/1520-0426(1999)016<0475:CSPIFS>2.0.CO;2 [12] Li Xiaofeng, Clemente-Colón P, Friedman K S. Estimating oceanic mixed-layer depth from internal wave evolution observed from radarsat-1 SAR[J]. Johns Hopkins APL Technical Digest, 2000, 21(1): 130−135. [13] Hong D B, Yang Chansu, Ouchi K. Estimation of internal wave velocity in the shallow South China Sea using single and multiple satellite images[J]. Remote Sensing Letters, 2015, 6(6): 448−457. doi: 10.1080/2150704X.2015.1034884 [14] Grisouard N, Staquet C, Gerkema T. Generation of internal solitary waves in a pycnocline by an internal wave beam: a numerical study[J]. Journal of Fluid Mechanics, 2011, 676: 491−513. doi: 10.1017/jfm.2011.61 [15] Cai Shuqun, Gan Zijun, Long Xiaomin. Some characteristics and evolution of the internal soliton in the northern South China Sea[J]. Chinese Science Bulletin, 2002, 47(1): 21−27. doi: 10.1360/02tb9004 [16] 吕海滨, 何宜军, 申辉. 基于Radon变换获取东沙群岛附近三个内孤立波的传播速度[J]. 海洋通报, 2013, 32(3): 251−255.Lv Haibin, He Yijun, Shen Hui. Calculation of the velocities of three internal solitary waves around Dongsha Islands based on Radon transform[J]. Marine Science Bulletin, 2013, 32(3): 251−255. [17] Li Youkai, Wang Caixia, Liang Chujin, et al. A simple early warning method for large internal solitary waves in the northern South China Sea[J]. Applied Ocean Research, 2016, 61: 167−174. doi: 10.1016/j.apor.2016.11.002 -
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