An Overview of Internal Solitary Waves in the South China Sea

Abstract

Internal solitary waves (ISWs) are the nonlinear large amplitude waves existing in the oceanic pycnocline. They are very active in the northern South China Sea (SCS). With more and more remote sensing data, in situ observational data and the development of the numerical simulation technology, a number of studies on the characteristics, the source site, the generation, and evolution of the ISWs in the SCS are reported. In this paper, earlier studies on the ISWs in the SCS are summarized and some problems worthy of study are put forward.

The formation and fate of internal waves in the South China Sea

“…When they shoal onto the continental slope to the west, the downward displacement of the ocean's layers associated with these solitary waves can exceed 250 m in 5 minutes 8 . On such a scale, these waves pose hazards for underwater navigation and offshore drilling 4 , and supply nutrients from the deep ocean that nourish coral reefs 1 and pilot whale populations that forage in their wakes 13 .Over the past decade a number of field studies have been conducted in the region; this work has been comprehensively reviewed 10,11 . All of these studies, however, focused on the propagation of the internal waves across the SCS and their interactions with the continental shelf of China.…”

“…Over a decade of studies [8][9][10][11] have targeted the South China Sea, where the oceans' most powerful internal waves are generated in the Luzon Strait and steepen dramatically as they propagate west. Confusion has persisted regarding their generation mechanism, variability and energy budget, however, due to the lack of in-situ data from the Luzon Strait, where extreme flow conditions make measurements challenging.…”

“…Over the past decade a number of field studies have been conducted in the region; this work has been comprehensively reviewed 10,11 . All of these studies, however, focused on the propagation of the internal waves across the SCS and their interactions with the continental shelf of China.…”

Analysis of kinematic parameters of Internal Solitary Waves in the Northern South China Sea

“…The northern South China Sea (NSCS) is featured by large Internal Solitary Waves (ISWs), which have been extensively observed (Cai et al 2012;Ramp et al 2004;Liu and Zhao, 2008;Zhao and Alford 2006;Alford et al, 2010Lien et al, 2014) and numerically simulated (Buijsman et al 2010a, b;Cai and Xie 2010;Zhang et al 2011;Shaw et al 2009;Guo et al 2011). ISWs travel in a near-westward direction over several hundreds of kilometers with wave speeds up to 3 ms À 1 , vertical isopycnal displacements of about 100 m, and crest lengths of over 100 km in the horizontal plane (Liu and Zhao, 2008).…”

Estimation of internal wave velocity in the shallow South China Sea using single and multiple satellite images

“…The ENVISAT-ASAR image in the ScanSAR mode was acquired at 02:20 (UTC) on 31 July 2010, and the Terra-MODIS image was acquired 55 minutes after the ENVISAT pass. The SCS is well known for IWs generated by the interaction between the tidal currents and bottom topography (Liu et al 1998;Apel 2002;Cai, Xie, and He 2012). The MODIS has 2330 km swath width with 36 spectral bands between 0.405 and 14.385 μm.…”