Flow structure decomposition and baroclinic M<sub>4</sub> constituent current exploration in estuarine zone

Li Yichun; Liu Jingui; Zhang Tianyu; Lu Shasha

doi:10.12284/hyxb2022198

Volume 44 Issue 10

Oct. 2022

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Li Yichun，Liu Jingui，Zhang Tianyu, et al. Flow structure decomposition and baroclinic M4 constituent current exploration in estuarine zone[J]. Haiyang Xuebao，2022, 44(10)：1–9 doi: 10.12284/hyxb2022198

Citation:

Li Yichun，Liu Jingui，Zhang Tianyu, et al. Flow structure decomposition and baroclinic M₄ constituent current exploration in estuarine zone[J]. Haiyang Xuebao，2022, 44(10)：1–9 doi: 10.12284/hyxb2022198

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Flow structure decomposition and baroclinic M₄ constituent current exploration in estuarine zone

doi: 10.12284/hyxb2022198

Li Yichun^{1, 2
,},
Liu Jingui^{1, 3, 4
,
,},
Zhang Tianyu^{1, 3, 4
,
,},
Lu Shasha⁵

1.
Guangdong Key Laboratory for Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang 524088, China
2.
College of Civil Engineering and Architecture, Beibu Gulf University, Qinzhou 535011, China
3.
Key Laboratory of Space Ocean Remote Sensing and Application, Ministry of Natural Resources, Beijing 100081, China
4.
Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Guangdong Ocean University, Zhanjiang 524088, China
5.
Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China

Received Date: 2022-04-13
Rev Recd Date: 2022-06-27

Available Online: 2022-07-21

Publish Date: 2022-10-01

Abstract

Abstract

Estuarine flow is the fundamental driving of physical processes such as estuarine ecological environment, river evolution and material transport. Due to the runoff, tide, topography and meteorology, the estuarine flow presents a complex three-dimensional structure, including not only the residual flow induced by fresh water injection, but also the periodical tidal current, wind-driven flow, baroclinic flow and the residual flow caused by estuarine nonlinearity. In order to explore the composition and intra-tidal variation of estuarine flow, based on the field data in the Oujiang River Estuary, the estuarine flow is decomposed by principal component analysis (PCA) method, and the decomposition performance of PCA method for estuarine flow and high-frequency characteristics of baroclinic overtide are deeply discussed. The results show that PCA method can operate original data or standardized data in the study of estuarine flow structure. PCA method can decompose baroclinic components (estuarine gravitational circulation structure), but cannot separate barotropic components (runoff and tidal current). The coupled effect of runoff and tidal current is reflected in the score of principal components. The filter of principal components should employ conjoint judgment of flow structure and cumulative interpretation variance, rather than only cumulative interpretation variance. The estuarine baroclinic flow has clearly high-frequency characteristics, which approximates quarter-diurnal.
- baroclinic,
- PCA,
- M₄ constituent,
- Oujiang River Estuary,
- estuarine gravitational circulation

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References(12)

References

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