粤西陆架温度锋三维结构与季节变化机制分析  

3D structure and seasonal variation of temperature fronts in the shelf sea west of Guangdong

作　　者：谭可易 谢玲玲[1,2,3] 李明明 李敏 李君益[1,2,3] Tan Keyi;Xie Lingling;Li Mingming;Li Min;Li Junyi(Laboratory of Coastal Ocean Variation and Disaster Prediction,College of Ocean and Meteorology,Guangdong Ocean University,Zhanjiang 524088,China;Key Laboratory of Climate,Resources and Environment in Continental Shelf Sea and Deep Ocean,Zhanjiang 524088,China;Key Laboratory of Space Ocean Remote Sensing and Application,Ministry of Natural Resources,Beijing 100081,China)

机构地区：[1]广东海洋大学海洋与气象学院近海海洋变化与灾害预警实验室,广东湛江524088 [2]陆架及深远海气候资源与环境广东省高等学校重点实验室,广东湛江524088 [3]自然资源部空间海洋遥感与应用重点实验室,北京100081

出　　处：《海洋学报》2023年第10期42-55,共14页

基　　金：国家自然科学基金面上项目(42276019)。

摘　　要：基于2018–2019年现场高分辨率温度观测和1993–2021年的CMEMS再分析海表温度(SST)和风场数据,分析粤西陆架海温盐锋的三维结构、季节变化和影响机制。多年SST数据显示,海表温度锋冬季最强、出现概率和覆盖宽度最大,量值分别为0.049℃/km、75%和66 km。春季和夏季次之,而秋季则几乎完全消失。冬季锋面平均离岸50 km,夏季则向岸靠近为23.1 km。2018年春季、夏季和2019年夏季的现场观测进一步给出锋面在次表层的三维结构,结果显示春、夏季20m等深线以浅处均有锋面存在,该锋面是沿岸高温海水与离岸低温海水辐聚而成,随着深度的增加锋面强度减小,覆盖范围向岸收缩。20m以深水域锋面在次表层中强于表层,随深度增加而增强并向岸偏移。相关性和信息流分析发现,海表面风应力旋度和沿岸风是影响粤西陆架海表温度锋面的重要因素。该温度锋存在年际变化,PDO负位相时的La Niña年锋面强度出现极大值,而PDO正位相时的El Niño年则对应极小值。Using reanalysis sea surface data and in-situ high-resolution observations in spring,summer 2018,and summer 2019,this study analyzes the 3D structure and seasonal variation of temperature fronts in the shelf sea west of Guangdong.The results show that the sea surface temperature(SST)fronts reach the strongest intensity up to 0.049°C/km in winter,with the largest occurrence probability of 75%and coverage of 66 km.The SST fronts weaken in spring and summer,and almost disappear in autumn.The average offshore distance of the front is 50 km in winter and 23.1 km in summer.The in-situ observations show a strong thermal front in coastal areas shallower than 20 m in both spring and summer.The front gets weaker and closer to the coast in deeper layers and is associated with warm coastal water and cold shelf water.In shelf areas deeper than 20 m,the fronts in the subsurface layer are stronger than in the surface layer and shift shoreward in deeper layers.The correlation coefficient and information flow between the surface wind and frontal parameters reveal that the surface wind stress curl and along-coast wind are the most important factors affecting the surface thermal front.These thermal fronts also have interannual variations,with maximum intensity in La Niña years with negative PDO and minimum intensity in El Niño years with positive PDO.

关 键 词：海洋锋 季节分布 三维结构 信息流 粤西陆架 

分 类 号：P731[天文地球—海洋科学]