利用光学遥感探测南中国海内波

Detection of Internal Solitary Wave in the South China Sea Using Optical Remote Sensing

由于内波生成、传播都发生在水下,常规手段如现场观测成本过高,且易受到环境的制约,很难得到足够的有效数据。中分辨率成像光谱仪(MODIS)以其图像覆盖范围大、时间分辨率高、数据公开免费等优势而成为内波研究的重要数据源,可以实现大范围的观测。选用2010年6月至2012年6月共两年的南中国海地区(0°N^23°N,102°E^121°E)MODIS观测图像作为数据源,使用ENVI软件对MODIS图像进行筛选与处理,对该海区的内波特征进行了统计分析,最终整合获得了最新的内波时空分布特征。结果表明:南中国南海西北部,尤其是东沙环礁附近海区是内波发生频率最高的海区,发源于吕宋海峡。在115°E附近的海南岛东部海区,内波波峰线与东沙群岛海区的内波波峰线有较明显的断开特征,可能内波在本地发源。时间分布表现为内波在夏季出现最多,春、秋季节次之,且春季内波出现略多于秋季,冬季最少。

The generation and propagation of internal wave occurs beneath the sea water, conventional methods such as field observations are restrained by weather conditions as well as other factors, it is difficult for researchers to get enough valid data. Moderate-resolution imaging spectroradiometer （MODIS） become the important research data sources of internal wave because of its large coverage, high temporal resolution, freedom data download, etc. A wide range observation of internal wave is possible with it. Based on data from MODIS, study on internal wave is conducted from June 2010 to June 2012 in South China Sea （0°N-23°N,102°E- 121°E）. A statistical analysis of temporal and spatial characteristics of internal waves is given. The results show that internal wave generates with a high frequency in the northwestern South China Sea, especially around Dongsha Atoll area which originates from Luzon Strait. In areas around 115°E east to Hainan Island, crest of waves have an obvious distinct characteristics from the waves of Dongsha Atoll, it is possible that there are local generation of internal wave. The temporal distribution of internal wave shows that most of internal waves are observed in summer and observation comes to the least in winter.