| The thermocline reflects the ocean temperature field's important physics characteristics. It has important influence on underwater communication, submarine activity as well as fishery farming and fishing. It has close relations with branch subjects such as ocean current, water mass, inside wave, sea and air exchange. Therefore, in the development process of domestic and international ocean science, thermocline, particularly the seasonal thermocline, is always one of the main subjects. In this text, according to South China Sea(SCS) hydrology investigation data, including the Nansen data, BT and CTD data , thermocline distribution of SCS and its characteristics have been studied. At same time, with the data of sun' s thermal radiation, air temperature, and other weather data the ocean thermocline has been calculated.The research involves the following aspects: large-scale data processing method; data quality control; thermocline identification and statistics method; thermocline map; thermocline influence factors of SCS; thermocline results comparison using Nansen data and BT data; thermocline forecast. Among them the analysis of thermocline distributional pattern and the influence factor of SCS are the core contents.Research results indicate that, with the thermocline intensity of standard 0.05℃/m as a measure, there are shallow thermocline and deep thermocline all the year round in SCS. The shallow thermocline distributes in the areas of Guangdong, Guangxi, Fujian and Vietnam continental shelf, with obviously seasonal variabilily,and at the same time, in the south and middle areas of Nanhai, even in winter when there is no thermocline in the coastal area, there also exists the shallow thermocline. All the year round deep the thermocline is always existent, having little relation with the weather condition. The thermocline area gets the largest in June, but its intensity gets the biggest in July. Compared with the time of the thermocline in Huanghai, East China Sea, the thermocline of SCS takes shape a month early, and no thermocline period takes place a month later. Because in July the sun's radiation is lower in SCS than East China Sea and the air temperature difference of winter and summer is smaller, the thermocline intensity is weaker in SCS than in Huanghai and East China Sea.This study has done a large amount of work on the thermocline statistical method, the result verification and plotting, and has brought forth some new ideas. The thermocline classification method has been worked out on the basis of the classification theory for various thermocline types and in the light of temperature profile characteristics of SCS. So the result can clearly reflect the distributional pattern of the thermocline in the South China Sea. |
