文献类型：期刊文献

英文题名：Identification and separation of baroclinic M4 current in estuaries

作者：Li, Yichun[1];Liu, Jingui[1,2,3];Lu, Shasha[4];Zhang, Tianyu[1,2,3]

机构：[1]Guangdong Ocean Univ GDOU, Coll Ocean & Meteorol, Zhanjiang 524088, Peoples R China;[2]Minist Nat Resources MNR, Key Lab Space Ocean Remote Sensing & Applicat, Beijing 100081, Peoples R China;[3]GDOU, Dept Educ Guangdong Prov, Key Lab Climate Resources & Environm Continental S, Zhanjiang 524088, Peoples R China;[4]MNR, Inst Oceanog 2, Key Lab Ocean Space Resource Management Technol, Hangzhou 310012, Peoples R China

年份：2023

卷号：290

外文期刊名：ESTUARINE COASTAL AND SHELF SCIENCE

收录：SCI-EXPANDED(收录号：WOS:001055486800001)、、Scopus(收录号：2-s2.0-85163809039)、WOS

基金：The research was supported by the National Natural Science Foundation of China (41976200) , Program for Scientific Research Start-up Funds of Guangdong Ocean University (060302032202, 060302032106) , First-class Discipline Plan of Guangdong Province (080503032101-231420003) , and Scientific Research Fund of the Sec-ond Institute of Oceanography, MNR (SZ2302) .

语种：英文

外文关键词：Estuarine zones; Tidal current asymmetry; Oujiang estuary; Baroclinic M4 current; M4 overtide

外文摘要：Tidal current asymmetry is a challenging issue in estuaries and is generally quantified based on the relative amplitude and phase of M4 constituents in semi-diurnal regions. Previous studies have focused on the barotropic M4 current (BTC), whereas baroclinic overtides are often ignored. Using field data and numerical simulation results, we established a separation method of the baroclinic M4 current (BCC), clarified its typical features in estuaries of large tidal range, and explored the mechanism of BCC from the perspective of frontogenesis. The results showed that a 180 degrees phase reversal in the vertical direction and significant enhancement of the normalised amplitude were fundamental features of BBC. Meanwhile, a decrease in currents around the salt intrusion head may not be inevitable owing to the strong BTC induced by nonlinearity, especially in meso-or macro-tidal estuaries. In contrast, near the river plume, BCC may develop and be stronger than BTC. Furthermore, BCC leads to zero longitudinal net transport of water mass, as it is treated as an 'oscillatory' full-depth lock-exchange flow. Our findings present a framework for BCC in estuarine zones.