Next Article in Journal
Daily Precipitation Changes over Large River Basins in China, 1960–2013
Previous Article in Journal
Suitability Evaluation of River Bank Filtration along the Second Songhua River, China
Previous Article in Special Issue
Decline of the Maurepas Swamp, Pontchartrain Basin, Louisiana, and Approaches to Restoration
Article Menu

Export Article

Open AccessArticle
Water 2016, 8(5), 184; doi:10.3390/w8050184

Drivers of Barotropic and Baroclinic Exchange through an Estuarine Navigation Channel in the Mississippi River Delta Plain

Wetland and Aquatic Research Center, U.S. Geological Survey, Baton Rouge, LA 70803, USA
Academic Editor: Y. Jun Xu
Received: 26 February 2016 / Revised: 18 April 2016 / Accepted: 26 April 2016 / Published: 30 April 2016
View Full-Text   |   Download PDF [6997 KB, uploaded 30 April 2016]   |  

Abstract

Estuarine navigation channels have long been recognized as conduits for saltwater intrusion into coastal wetlands. Salt flux decomposition and time series measurements of velocity and salinity were used to examine salt flux components and drivers of baroclinic and barotropic exchange in the Houma Navigation Channel, an estuarine channel located in the Mississippi River delta plain that receives substantial freshwater inputs from the Mississippi-Atchafalaya River system at its inland extent. Two modes of vertical current structure were identified from the time series data. The first mode, accounting for 90% of the total flow field variability, strongly resembled a barotropic current structure and was coherent with alongshelf wind stress over the coastal Gulf of Mexico. The second mode was indicative of gravitational circulation and was linked to variability in tidal stirring and the horizontal salinity gradient along the channel’s length. Tidal oscillatory salt flux was more important than gravitational circulation in transporting salt upestuary, except over equatorial phases of the fortnightly tidal cycle during times when river inflows were minimal. During all tidal cycles sampled, the advective flux, driven by a combination of freshwater discharge and wind-driven changes in storage, was the dominant transport term, and net flux of salt was always out of the estuary. These findings indicate that although human-made channels can effectively facilitate inland intrusion of saline water, this intrusion can be minimized or even reversed when they are subject to significant freshwater inputs. View Full-Text
Keywords: estuaries; salt transport; circulation; wavelet analysis; Mississippi River delta estuaries; salt transport; circulation; wavelet analysis; Mississippi River delta
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Snedden, G.A. Drivers of Barotropic and Baroclinic Exchange through an Estuarine Navigation Channel in the Mississippi River Delta Plain. Water 2016, 8, 184.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Water EISSN 2073-4441 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top