黄海冷水团消衰期天气尺度变化及机制研究

The Yellow Sea Cold Water Mass (YSCWM) is an important physical feature of the China Sea. Many studies on the YSCWM focus on its features in summer or its seasonal and interannual variations rather than the synoptic scale variability. Our recent study shows that the temperature of the bottom water in the western Yellow Sea increased sharply from late autumn to early winter, and the synoptic scale variability in temperature indicated the decay of the YSCWM. This program will study the distribution of the water whose temperature increases during the decay period of the YSCWM, and reveal the mechanisms for the significant rise in temperature with the observed and simulated data. The main purpose of this work is to clarify the mechanisms for variations of the YSCWM during its decay period via a description of the synoptic scale variability features of the thermocline and the front, and with an analysis of the influence of the vertical mixing on the synoptic and seasonal variations. The work will be helpful for understanding the decay mechanisms of the YSCWM, the dynamic and thermodynamic processes in this region, and the regional air-sea interaction.

黄海冷水团是我国近海重要的海洋现象，目前对黄海冷水团的研究或专注于夏季的特征，或侧重其季节和年际变化，而针对黄海冷水团天气尺度变化的研究较少。本项目申请人的初步分析表明，秋、冬季节黄海西部底层水有非常显著的天气尺度的升温现象，而且这一天气尺度的变化指示着黄海冷水团季节尺度的消衰。本项目将利用中国近海综合调查项目潜标数据、大面观测数据以及之后申请人所在单位在黄海四航次潜标数据，结合数值模拟手段，以黄海冷水团消衰期黄海西部天气尺度的增温现象为出发点，研究冷水团消衰期升温海水的三维分布，揭示秋、冬季节海水升温机制。通过重点分析跃层、锋面在冷水团消衰期的天气尺度变化特征以及垂直混合在黄海冷水团消衰期天气、季节多时间尺度变化中的作用，阐明黄海冷水团消衰期的变化特征及机制。这项工作对于深入认识黄海冷水团消衰机理，深入认识该海域的动力、热力学过程和区域海气相互作用都具有重要的科学意义。

黄海冷水团是我国近海重要的海洋现象。本项目利用中国近海综合调查项目潜标数据、大面观测数据结合数值模拟手段，以黄海冷水团消衰期黄海西部天气尺度的增温现象为出发点，研究冷水团消衰期升温海水的三维分布，揭示秋、冬季节海水升温机制。北风产生的Ekman输运，在黄海西部斜坡海区造成下降流，即底层水向东流动，结合底层温度分布，造成海水升温。包围着黄海冷水团的温度锋面和跃层都呈现天气尺度的变化。锋面随着北风的变化而震荡，同时向冷水团中心收缩并逐渐变弱。温跃层随着北风的变化逐渐变深、变厚并较弱。锋面和跃层天气尺度的变化最终导致黄海冷水团季节尺度的消亡。这项工作对于深入认识黄海冷水团消衰机理，深入认识该海域的动力、热力学过程和区域海气相互作用都具有重要的科学意义。