PhD Dissertation Defense: David Marshall

The PhD Dissertation Defense of David Marshall is presented by UNC-CH Department of Marine Sciences and UNC’s Institute of Marine Sciences (IMS). The main location of this event will be in room 222 at IMS in Morehead City, NC. The defense will also be streamed live to conference room 3204 on the 3rd floor of Murray Hall on UNC-CH campus in Chapel Hill, NC. This event will be held on Tuesday, April 24th at 1:00 PM.

Title:  Dynamics and mixing in a microtidal, wind-driven estuary

Abstract: In estuaries, tides are considered to be the dominant mechanism driving the mixing of freshwater from rivers with the saline waters from the adjoining ocean, hence determining the along-estuary salinity gradient and strength of estuarine circulation. However, there are a number of microtidal estuaries, driven primarily by the wind and not tides. These estuaries are prone to human-induced water quality problems, as the episodic nature of wind leads to less vertical mixing and strong stratification, which when combined with eutrophication results in bottom-water hypoxia. My dissertation research aims to further our understanding of the dynamics and mixing in these wind-driven estuaries. Through field measurements collected in the Neuse River Estuary in 2013 and 2016, I first investigate the along-channel momentum and salt budgets to determine the primary balances in a wind driven estuary. I then define a new set of mixing parameters to compare it to classical tidal estuaries. Finally, I characterize the nature and efficiency of turbulent mixing produced in the Neuse.