基于再分析数据的南海三维温盐结构特征分析

An Analysis of 3D Characterization of Temperature-salinity Structure 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。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 25~32℃，最高温度出现在 8 月的黄岩岛附近海域，海表盐度一般为 32~35 psu，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:

Mastering the 3D（three-dimensional）Characteristics of the temperature-salinity field in the South China Sea（SCS）is of great significance for studying SCS dynamic environment and its influence on climate change. Based on the 2020 ocean reanalysis data GLORYS12V1，the horizontal distribution，vertical structure characteristics， and seasonal changes of SCS temperature-salinity are analyzed. The analysis results show that the SCS surface temperature is generally between 25℃ and 32℃，and the highest temperature occurs in the waters near Huangyan Island in August. The annual SCS surface salinity is generally between 32 psu and 35 psu，and the highest salinity occurs in July. The vertical structure of temperature-salinity exhibits high temperature and low salinity on the surface layer，and the seasonal variation of temperature-salinity decreases with increasing depth. The depth of the SCS thermocline has obvious seasonal variations and it is greater in autumn and winter than that in spring and summer. According to the variation characteristics of sea surface temperature during Typhoon Rammasun，the response of sea surface temperature to the typhoon process is analyzed. The vertical mixing effect of the SCS water is enhanced and sea surface temperature decreases significantly during typhoon.