黑潮入侵对南海东北部内孤立波的影响机制研究

The deep-sea resources in the northeastern South China Sea are of significant importance for China due to its large oil and gas reserves, and this ocean area is one of the most active areas of internal solitary waves. Internal solitary waves must be considered in the project for deep-sea resources exploitation, thus investigations on the influencing factors and generation and evolution mechanism of internal solitary waves are of great importance for the deep-sea resources exploitation in South China Sea. Kuroshio intrusion is one of the major factors affecting the generation and propagation of internal solitary waves in the northeastern South China Sea. However, the influence of Kuroshio intrusion is still not quite clear. Two-dimensional models are usually used in the previous studies, which can not fully describe the influence of Kuroshio intrusion. The three-dimensional nonhydrostatic model is to be developed to address this issue. Numerical simulations are to be carried out to study the complex current and variation of the ocean stratification induced by the Kuroshio intrusion, and reveal the influence mechanism of Kuroshio intrusion on the internal solitary wave in the northeastern South China Sea. The above investigations are of significant importance for addressing the mechanism of generation and evolution of internal solitary waves in the northeastern South China Sea.

南海东北部海域油气资源储量较多，在我国深海资源的开发中具有重要地位，该海域也是内孤立波出现较频繁的海域。内孤立波是南海深海资源开发过程中必须考虑的重要环境要素，研究内孤立波的影响因素与生成演变机制对我国深海资源开发具有重要的意义。黑潮入侵南海是影响南海东北部内孤立波生成与传播的重要因素之一，但黑潮入侵对南海内孤立波的影响机制目前尚不完全清楚。以往研究主要采用两层理论模式或垂向二维模型，不能全面反映黑潮的影响。本项目将建立三维非静压数学模型，结合实测资料，模拟研究黑潮入侵所引起的复杂海流与海水层化的变化，探明黑潮入侵对南海东北部内孤立波生成与传播的影响机制。上述工作对揭示南海东北部内孤立波的生成演化机制具有重要的科学意义。

内孤立波是海洋工程、水下潜航器等设计中需要考虑的重要影响因素。南海东北部海域是内孤立波的频发海域，同时也是我国油气资源的富集区。针对南海东北部内孤立波，项目建立了实际海底地形条件下的南海东北部内孤立波三维非静压模型，可模拟南海东北部内孤立波的生成与传播演变过程。结合观测数据、遥感资料等，利用所建立的三维非静压模型，对南海东北部内孤立波展开了相关研究。主要包括：模拟研究了陆坡陆架区域第二模态内孤立波的生成机制，结果表明，陆坡陆架区域的第二模态内孤立波可能源于第一模态内孤立波和局地底部地形相互作用与内潮的联合影响；探讨了陆坡陆架区域波幅较小的b波传播相对波幅较大的a波较快的机制，发现内潮对内孤立波的调制作用是其主要原因；研究讨论了黑潮入侵引起的温盐场与流场变化对内孤立波的影响，结果表明，黑潮入侵引起的温盐场与流场变化综合起来可能是冬季南海东北部内孤立波出现频次较少的原因。上述成果为进一步揭示南海东北部内孤立波的生成传播演变机制奠定了基础，将来可为南海深水油气资源开发提供水下内波场信息。