气候变化领域集成服务门户(CCPortal): Using Tracer Variance Decay to Quantify Variability of Salinity Mixing in the Hudson River Estuary

CCPortal

DOI	10.1029/2020JC016096
	Using Tracer Variance Decay to Quantify Variability of Salinity Mixing in the Hudson River Estuary
	Warner J.C.; Geyer W.R.; Ralston D.K.; Kalra T.
发表日期	2020
ISSN	21699275
卷号	125 期号:12
英文摘要	The salinity structure in an estuary is controlled by time-dependent mixing processes. However, the locations and temporal variability of where significant mixing occurs is not well-understood. Here we utilize a tracer variance approach to demonstrate the spatial and temporal structure of salinity mixing in the Hudson River Estuary. We run a 4-month hydrodynamic simulation of the tides, currents, and salinity that captures the spring-neap tidal variability as well as wind-driven and freshwater flow events. On a spring-neap time scale, salinity variance dissipation (mixing) occurs predominantly during the transition from neap to spring tides. On a tidal time scale, 60% of the salinity variance dissipation occurs during ebb tides and 40% during flood tides. Spatially, mixing during ebbs occurs primarily where lateral bottom salinity fronts intersect the bed at the transition from the main channel to adjacent shoals. During ebbs, these lateral fronts form seaward of constrictions located at multiple locations along the estuary. During floods, mixing is generated by a shear layer elevated in the water column at the top of the mixed bottom boundary layer, where variations in the along channel density gradients locally enhance the baroclinic pressure gradient leading to stronger vertical shear and more mixing. For both ebb and flood, the mixing occurs at the location of overlap of strong vertical stratification and eddy diffusivity, not at the maximum of either of those quantities. This understanding lends a new insight to the spatial and time dependence of the estuarine salinity structure. © 2020 The Authors. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
英文关键词	Hudson River Estuary; mixing; numerical modeling; tracer variance
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/186540
作者单位	Woods Hole Coastal and Marine Science Center, U.S. Geological Survey, Woods Hole, MA, United States; Applied Ocean Physics and Engineering Department, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Integrated Statistics, Contracted to the U.S Geological Survey, Woods Hole, MA, United States
推荐引用方式 GB/T 7714	Warner J.C.,Geyer W.R.,Ralston D.K.,et al. Using Tracer Variance Decay to Quantify Variability of Salinity Mixing in the Hudson River Estuary[J],2020,125(12).
APA	Warner J.C.,Geyer W.R.,Ralston D.K.,&Kalra T..(2020).Using Tracer Variance Decay to Quantify Variability of Salinity Mixing in the Hudson River Estuary.Journal of Geophysical Research: Oceans,125(12).
MLA	Warner J.C.,et al."Using Tracer Variance Decay to Quantify Variability of Salinity Mixing in the Hudson River Estuary".Journal of Geophysical Research: Oceans 125.12(2020).