热带海洋学报 ›› 2019, Vol. 38 ›› Issue (3): 43-52.doi: 10.11978/2018098

• 海洋水文学 • 上一篇    下一篇

基于高精度海洋动力模型的珠江口羽状流季节和年际变化规律研究

徐闯1,许永基1,胡嘉镗1,2(),李适宇1,2(),刘晋涛1   

  1. 1. 中山大学环境科学与工程学院, 广东 广州 510275
    2. 广东省环境污染控制与修复技术重点实验室, 广东 广州 510275
  • 收稿日期:2018-09-29 修回日期:2018-12-04 出版日期:2019-05-20 发布日期:2019-06-17
  • 通讯作者: 胡嘉镗,李适宇
  • 作者简介:徐闯(1991—), 男, 河南省南阳市人, 硕士研究生, 主要从事近岸海洋动力模拟研究。E-mail:xuch46@mail2.sysu.edu.cn
  • 基金资助:
    中央高校基本科研业务费专项资金(17lgzd20);热带海洋环境国家重点实验室(中国科学院南海海洋研究所)开放课题(LTO1605);国家自然科学基金(41306105)

Study on the seasonal and interannual variability of river plume in the Pearl River Estuary based on a high-resolution ocean dynamic model

Chuang XU1,Yongji XU1,Jiatang HU1,2(),Shiyu LI1,2(),Jintao LIU1   

  1. 1. School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
    2. Guangdong Province Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China
  • Received:2018-09-29 Revised:2018-12-04 Online:2019-05-20 Published:2019-06-17
  • Contact: Jiatang HU,Shiyu LI
  • Supported by:
    Fundamental Research Funds for the Central Universities(17lgzd20);State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences(LTO1605);National Natural Science Foundation of China(41306105)

摘要:

基于高精度海洋动力模型FVCOM (finite-volume community ocean model), 模拟分析了1999—2010年珠江口羽状流的季节和年际变化规律, 并结合经验正交函数(empirical orthogonal function, EOF)分析探讨了影响珠江口羽状流扩展变化的主要动力因子。采用模拟时段内的现场观测数据对多年模拟结果进行验证, 结果表明模型具有较高的精度, 能够较好地模拟珠江口羽状流的扩展变化规律。模拟结果显示, 珠江口羽状流存在显著的季节变化。夏季, 受大径流和西南风的影响, 羽状流的扩展呈现双向特征, 即粤西沿岸扩展和粤东离岸扩展同时存在, 扩展范围最大; 冬季, 径流衰减为最小值, 风场转变为强烈的东北风, 羽状流被紧紧挤压在西岸, 形成狭窄的条带状, 扩展范围最小; 春、秋两季属于过渡季节, 羽状流扩展情况类似, 均表现为沿岸向粤西扩展。年际变化层面, 夏季羽状流的年际变化最为显著, 呈现粤东扩展占优型、近似对称型和粤西扩展占优型三种形态; 春季羽状流的年际变化次之, 羽状流的差异主要体现在珠江口和粤西海域; 秋、冬两季羽状流的年际变化较小, 尤以冬季最小。EOF分析的第一模态可以解释整体变化的91.2%, 反映了径流量对珠江口羽状流的影响; 第二模态可以解释整体变化的4.1%, 反映了盛行风对珠江口羽状流的影响。

关键词: 羽状流, 季节变化, 年际变化, EOF分析, 数值模式, 珠江口

Abstract:

Based on the sea surface salinity data from 1999 to 2010 simulated by the high-resolution Finite-Volume Community Ocean Model (FVCOM), the seasonal and interannual variability of river plume in the Pearl River Estuary was analyzed and the main dynamic factors related to the variability were also discussed in combination with Empirical Orthogonal Function (EOF) analysis in this study. The field observation data during the simulation period were used to verify the simulation results for the 12 years, and the verification results showed that the model had higher accuracy and simulated the extension and variability of the plume fairly well. The simulated results showed that the plume exhibited significant seasonal variability. Affected by the high river discharge and southwesterly wind, the summertime plume exhibited a bidirectional structure with the plume extending westward attaching to the coast and eastward detaching from the coast. The extension area of the summertime plume was the largest. In winter, the river discharge attenuated to a minimum and the wind field changed into strong northeasterly wind. Consequently, the plume was squeezed to the western coast tightly to form a narrow band with the smallest extension area. The spring and autumn periods were transitional seasons, and the plume in these two seasons exhibited westward alongshore spreading. The summertime plume exhibited significant interannual variability with three main patterns, namely, the eastward extension dominated, approximately symmetric extension and westward extension dominated. In spring, the interannual variability of the plume was followed by that in summer and the variability mostly occurred in the western region and river estuary. The interannual variability in autumn and winter was not significant, especially in winter. The first EOF mode could explain 91.2% of the total variance, corresponding to the change in river discharge. The second EOF mode could explain 4.1% of the total variance, corresponding to the change in prevailing wind.

Key words: plume, seasonal variability, interannual variability, EOF analysis, numerical model, Pearl River Estuary

中图分类号: 

  • P731.21