Residence Time of a Highly Urbanized Estuary: Jamaica Bay, New York
| Autor: | Philip M. Orton, Reza Marsooli, Heather Smith, James Fitzpatrick |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Hydrology geography Tidal range geography.geographical_feature_category 010504 meteorology & atmospheric sciences 010604 marine biology & hydrobiology Hypoxia (environmental) Ocean Engineering Estuary 01 natural sciences residence time tidal prism method Jamaica Bay Grassy Bay tracer transport hydrodynamic medicine Environmental science Flushing Tidal prism Water quality medicine.symptom Eutrophication Bay 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering |
| Zdroj: | Journal of Marine Science and Engineering; Volume 6; Issue 2; Pages: 44 |
| ISSN: | 2077-1312 |
| Popis: | Using a validated coupled hydrodynamic-tracer transport model, this study quantified the mean residence time in Jamaica Bay, a highly eutrophic lagoonal estuary in New York City. The Bay is a well-mixed to partially-stratified estuary with heavily-dredged bathymetry and substantial wastewater treatment plant effluent inputs that lead to seasonal hypoxia in some poorly-flushed deep-water basins. Residence time was computed for Jamaica Bay and its largest isolated deep basin, Grassy Bay. The response of residence time to freshwater discharge and wind forcing during summer 2015 was also investigated. The model results showed that the mean residence time, which represents the time required to flush out 63% of tracers released into the region of interest, was 17.9 days in Jamaica Bay and 10.7 days in Grassy Bay. The results also showed that some regions in Jamaica Bay retained their tracers much longer than the calculated residence time and, thus, are potentially prone to water quality problems. Model experiments demonstrated that summertime wind forcing caused a small increase in residence time, whereas freshwater discharge substantially reduced residence time. Freshwater inputs were shown to strongly enhance the two-layer estuarine gravitational circulation and vertical shear, which likely reduced residence time by enhancing shear dispersion. Due to the Bay’s small, highly-urbanized watershed, freshwater inputs are largely derived from the municipal water supply, which is fairly uniform year-round. This water helps to promote bay flushing, yet also carries a high nitrogen load from wastewater treatment. Lastly, the tidal prism method was used to create a simple calibrated model of residence time using the geometry of the study area and the tidal range and period. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|