基于潜标观测的南海北部陆架海域内潮时空变化特征  

Spatiotemporal Characteristics of Internal Tides on the Continental Shelf of the Northern South China Sea Based on Mooring Observations

作　　者：尹汉军 谢波涛 张琪 黄必桂 黄晓冬[2,3] YIN Hanjun;XIE Botao;ZHANG Qi;HUANG Bigui;HUANG Xiaodong(China National Offshore Oil Corporation Research Institute Company Limited,Beijing 100028,China;Key Laboratory of Ocean Observation and Information of Hainan Province,Sanya Oceanographic Institution,Ocean University of China,Sanya 572024,China;Key Laboratory of Physical Oceanography of the Ministry of Education,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]中国海洋大学三亚海洋研究院海南省海洋立体观测与信息重点实验室,海南三亚572024 [3]中国海洋大学物理海洋教育部重点实验室,山东青岛266100

出　　处：《海洋科学进展》2024年第4期611-622,共12页Advances in Marine Science

基　　金：中海石油(中国)有限公司科技项目(YXKY-ZX 10 2021);中国海洋石油集团总公司“十四五”重大科技项目(KJGG2022-0202);三亚崖州湾科技城科技计划项目(SKJC-2022-01-001);海南省“南海新星”科技创新人才平台项目(NHXXRCXM202364)。

摘　　要：为加深对南海北部陆架区域内潮特征的了解,本文利用位于南海北部陆架海域的2套潜标观测资料,研究了南海北部油气区内潮的时空变化特征。通过提取斜压流速并滤波后发现,LF2站位内潮较强,内潮最大流速为8.32 cm·s^(-1),出现在水下290 m深度处。小波分析和能量诊断结果显示,上述2个潜标观测到的半日内潮能量比全日内潮能量整体上小1~2个数量级。LF2站位处全日内潮以第二模态为主,半日内潮以第一模态为主;LH2站位处的全日内潮以第一模态为主,半日内潮则第一和第二模态并重。上述2个潜标测站全日内潮传播方向接近正N向、半日内潮传播方向多为NW向,但在10月中旬LF2站位处半日内潮传播方向由NW向变为NS向,LH2站位处全日内潮方向由正N向变为NE向。分析实测背景流发现,10月中旬内潮传播方向的改变可能与背景场的变化有关。本文的结果将有助于加深对陆架区内潮的时空特征的认识,促进对南海北部油气区内波时空变化机制的了解。Based on the observational data from two moorings deployed in the northern South China Sea,the spatiotemporal variation of internal tide(IT)in the oil and gas field is investigated.The results show that IT at the station LF2 was stronger and the maximum baroclinic tidal current was 8.3 cm∙s^(-1),which appeared at 290 m depth.Wavelet and energy analysis show that the energy of semidiurnal IT was 1-2 orders smaller than that of diurnal IT in magnitude.The vertical structure of diurnal IT at LF2 was dominated by the second mode while the semidiurnal IT was dominated by the first mode.The diurnal IT at LH2 was dominated by the first mode,but the semidiurnal IT was characterized by both the first and second modes.The averaged propagation directions of diurnal IT at the two mooring ststions were both close to due north,while the semidiurnal IT propagated mostly northwestward.However,in mid October,the semidiurnal IT propagation direction at LF2 changed from northwest to southwest,and the diurnal IT propagation direction at LH2 changed from north to northeast.With the analysis of background flow,it is found that the change of IT propagation direction in mid October is probably caused by the change in background field.These findings will help to deepen our understanding of the temporal and spatial characteristics of ITs in the continental shelf area and promote our understanding on the variation mechanisms of the IT in the oil and gas field in the northern South China Sea.

关 键 词：南海北部 陆架区内波 内潮 垂向模态 

分 类 号：P731.24[天文地球—海洋科学]