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In previous water quality modeling studies in Chesapeake Bay, the severity of summer hypoxia tended to be underestimated in the mid-lower Bay area. The underlying reason has not been well understood. In this study, we test a new hypothesis with respect to the estuary–ocean exchange. This hypothesis was motivated by observed high levels of dissolved organic carbon (DOC) near the Bay mouth that, if transported into the Bay, coul...
Frontal zones within the Western Alboran Gyre (WAG) are characterized by a density gradient resulting from the convergence of Atlantic and Mediterranean waters. Subduction along isopycnals at the WAG periphery can play a crucial role in upper-ocean ventilation and influences its stratification and biogeochemical cycles. In 2019, physical parameters (comprising temperature, salinity, turbulent kinetic energy dissipation rates)...
Oxygen depletion in coastal waters is increasing globally due primarily to eutrophication and warming. Hypoxia responses to nutrient loading and climate change have been extensively studied in large systems like the Chesapeake Bay and the Baltic Sea, while fewer studies have investigated smaller, shallower hypoxic zones. Thus, an improved understanding of the interactions of eutrophication and warming on hypoxia expansion (or...
Understanding shallow water biogeochemical dynamics is a challenge in coastal regions, due to the presence of highly variable land-water interface fluxes, tight coupling with sediment processes, tidal dynamics, and diurnal variability in biogeochemical processes. While the deployment of continuous monitoring devices has improved our understanding of high-frequency (12 - 24 hours) variability and spatial heterogeneity in shallo...
We examined responses of water‐column conditions, sediment‐water fluxes, ecosystem metabolism, and nutrient export in the Back River estuary during the past three decades following multiple phases of nutrient load reductions from a large wastewater treatment plant. Total nitrogen (TN) loads from the treatment plant declined from 7000 kg N d −1 in the mid‐1980s to 1500 kg N d −1 following the implementation of enhanced nutrient...
Supply‐controlled calcium carbonate dissolution decouples the seasonal dissolved oxygen and pH minima in Chesapeake BayNARA Subscribed
Acidification can present a stress on organisms and habitats in estuaries in addition to hypoxia. Although oxygen and pH decreases are generally coupled due to aerobic respiration, pH dynamics may be more complex given the multiple modes of buffering in the carbonate system. We studied the seasonal cycle of dissolved oxygen (DO), pH, dissolved inorganic carbon, total alkalinity, and calcium ion (Ca 2+ ) along the main channel...
Seasonal and spatial variability in surface p CO 2 and air–water CO 2 flux in the Chesapeake BayNARA Subscribed
Interactions between riverine inputs, internal cycling, and oceanic exchange result in dynamic variations in the partial pressure of carbon dioxide ( p CO 2 ) in large estuaries. Here, we report the first bay‐wide, annual‐scale observations of surface p CO 2 and air–water CO 2 flux along the main stem of the Chesapeake Bay, revealing large annual variations in p CO 2 (43–3408 μ atm) and a spatial‐dependence of p CO 2 on intern...