气候变化领域集成服务门户(CCPortal): A Global Classification of Astronomical Tide Asymmetry and Periodicity Using Statistical and Cluster Analysis

CCPortal

DOI	10.1029/2020JC016143
	A Global Classification of Astronomical Tide Asymmetry and Periodicity Using Statistical and Cluster Analysis
	Núñez P.; Castanedo S.; Medina R.
发表日期	2020
ISSN	21699275
卷号	125 期号:8
英文摘要	Tidal asymmetry plays a key role in the behavior of estuaries. Positive and negative asymmetries are associated with flood- and ebb-dominated estuaries, respectively. Asymmetry arises from both the interaction among the main tidal constituents and the harmonics generated when tide propagates in shallow waters. Most previous research focuses on the deformation of the tide within estuaries; however, ocean tide may show asymmetry at the estuary entrance, which implies that the boundary condition is already deformed. This fact has important implications for tide propagation, estuarine transport processes, and flow exchanges between estuaries and open oceans. In this study, the global astronomical tide is classified according to its asymmetry and periodicity. The objective is to provide a guiding framework of representative astronomical tide types (ATtypes) on a worldwide scale to be used as a reference for further research on the transport of substances in estuaries. The applied methodology is based on the use of the TPXO9-atlas global barotropic tidal solution and detailed statistical analysis. Probability density functions of the tidal elevation time derivative and the tidal form factor were extracted from TPXO9-atlas with a spatial resolution ranging from 1/6° to 1/30°. The K-means algorithm was applied to these parameters, and 25 representative ATtypes were identified. The classification was validated with 757 worldwide tide gauge records. The results show that 11.3% of coastal areas show negative asymmetries, 11.3% positive asymmetries, while symmetric tides dominate 77.4% of coastal areas. In these areas, estuaries can show asymmetries exclusively dependent on overtides and compound tides generated during inland propagation without being externally conditioned. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	kurtosis; probability density functions; skewness; tidal asymmetry; tidal form number; TPXO
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186715
作者单位	IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria, C/Isabel Torres 15, Santander, Spain; Departamento de Ciencias y Técnicas del Agua y del Medio Ambiente, E.T.S.I. de Caminos, Canales y Puertos, Universidad de Cantabria, Avda. de los Castros s/n, Santander, Spain
推荐引用方式 GB/T 7714	Núñez P.,Castanedo S.,Medina R.. A Global Classification of Astronomical Tide Asymmetry and Periodicity Using Statistical and Cluster Analysis[J],2020,125(8).
APA	Núñez P.,Castanedo S.,&Medina R..(2020).A Global Classification of Astronomical Tide Asymmetry and Periodicity Using Statistical and Cluster Analysis.Journal of Geophysical Research: Oceans,125(8).
MLA	Núñez P.,et al."A Global Classification of Astronomical Tide Asymmetry and Periodicity Using Statistical and Cluster Analysis".Journal of Geophysical Research: Oceans 125.8(2020).