Date of Award

Spring 2019

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

School

Ocean Science and Engineering

Committee Chair

Dr. Jerry Wiggert

Committee Chair School

Ocean Science and Engineering

Committee Member 2

Dr. Gregory Carter

Committee Member 2 School

Ocean Science and Engineering

Committee Member 3

Dr. Ian Church

Committee Member 4

Dr. Scott Milroy

Committee Member 4 School

Ocean Science and Engineering

Committee Member 5

Dr. Davin Wallace

Committee Member 5 School

Ocean Science and Engineering

Abstract

Tidal passes between Mississippi Sound (MS Sound) and Mississippi Bight (MS Bight) act as a transport pathway for the exchange of estuarine discharge and suspended particulate matter. A better understanding of sediment and particulate matter exchange can provide insights into turbidity, nutrient supply and aquatic ecosystem health for the region. This work examined the effects of different forcing factors (e.g. wind and tides) on the advection of suspended sediments and particulate matter in the study area. Fieldwork included particle size distribution, Acoustic Doppler Current Profiler (ADCP) and conductivity-temperature-depth measurements in the MS Sound and MS Bight from summer 2015 through summer 2016 with the aim being to characterize the seasonal distribution of suspended sediments and particulate matter. A Moderate Resolution Imaging Spectroradiometer 645-nm suspended particulate matter anomaly (SPMa) expanded the spatial scale of the field measurements and extended the temporal coverage from winter 2014 to fall 2016. The physical and sediment component of a regional numerical model in addition to the ADCP’s echo intensity were calibrated using in situ suspended sediment concentration (SSC), temperature, salinity and particle size data. SSC and SPMa were the final output of the model and remote sensing analysis used to investigate the exchange/transport of suspended sediments and particulate matter from the MS Sound to the MS Bight through the passes. Results provided information on changes in SSC/SPMa and timescales of the exchange. The exchange of coastal waters through the passes and the resulting shoreward advection of high salinity bottom water during a cold front caused increased SSC in MS Bight. The horizontal density gradient between the MS Sound and MS Bight in spring drives particulate matter exchange in the surface water on a time scale of weeks. The results in this study have implications for pollutants transported by suspended sediments and particulate matter in the MS Sound and MS Bight.

Available for download on Tuesday, December 10, 2019

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Oceanography Commons

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