基于再分析数据的南海三维温盐结构特征分析

Analysis of three-dimensional temperature and salinity structure characteristics in the South China Sea based on reanalysis data

摘要:

掌握南海三维温盐场特征对于研究南海海洋动力环境及其对海洋气候变化的影响具有重要意义。本文基于海洋再分析数据GLORYS12V1和AVHRR OISST数据，开展了南海温盐空间分布及季节变化分析，以及海表温度对台风过程的响应特征分析。分析结果表明，南海海表温度一般为25°C-32°C，最高温度出现在8月的黄岩岛附近海域，海表盐度一般为32psu-35psu，最高盐度出现在7月的东海附近海域；温盐垂向结构表现为表层高温低盐，随着深度增加温盐季节性变化越小。南海地区温跃层深度存在明显季节变化特征，秋冬季节温跃层深度大于春夏两季。根据"威马逊"台风期间海表温度变化特征分析海表温度对台风过程的响应，台风期间南海水体垂向混合作用增强，海表温度降温明显。

Abstract:

The three-dimensional ocean temperature and salinity field is a key parameter for mastering underwater dynamic processes and understanding the physical properties of seawater in the South China Sea region. Accurately describing the three-dimensional temperature and salinity structure characteristics of the South China Sea is of great significance for understanding climate change in the region. Based on the 2020 ocean reanalysis data GLORYS12V1,the horizontal distribution, vertical structure characteristics, and seasonal changes of temperature and salinity in the South China Sea were analyzed. The analysis results showed that the surface temperature of the South China Sea was between25°C and32°C in that year, and the highest temperature of the year occurred in the waters near Huangyan Island in August. The annual surface salinity of the sea was between 32psu and 35psu, and the highest salinity occurred in the waters near the East China Sea in July. The vertical structure of temperature and salinity exhibits high temperature and low salinity on the surface, and the seasonal variation of temperature and salinity becomes weaker with increasing depth.The temperature of seawater decreases with increasing depth, the salinity decreases with increasing depth from 180m to 380m, and the salinity increases with increasing depth at other depths. The response of sea surface temperature to typhoon processes was analyzed using satellite sea surface temperature data before and after typhoon passage. During the passage of Typhoon Wilmason, the vertical mixing effect of the South China Sea water was enhanced, and the sea surface temperature significantly cooled.