Impacts of Hydrology and Extreme Events on Dissolved Organic Carbon Dynamics in a Heavily Urbanized Estuary and Its Major Tributaries: A View From Space

Journal of Geophysical Research Biogeosciences, Journal Year: 2024, Volume and Issue: 129(3)

Published: Feb. 29, 2024

Abstract Dissolved organic matter and its colored component, Colored Organic Matter (CDOM), play a major role in global carbon budgets, their fluxes provide an essential link between terrestrial aquatic biogeochemical cycles. Satellite observations can uniquely capture the hydro‐biogeochemical connectivity of landscapes, across scales. Yet, accurate satellite retrievals CDOM dissolved (DOC) dynamics remain challenging urbanized estuaries coasts. Here, we present advanced unified algorithm for space‐based retrieval coastal DOC application Long Island Sound—one world's most heavily that is becoming increasingly vulnerable to climate change stressors. A rich bio‐optical data set, encompassing wide range environmental conditions, was integrated into training retrieve concentrations spectral shape (i.e., slope S 275–295 )—a proxy quality. The new algorithms were applied full‐resolution imagery from Sentinel‐3 Ocean Land Color Instrument (OLCI) after thoroughly evaluating performance six ocean color atmospheric correction approaches (ACOLITE, BAC, C2RCC, MUMM, l2gen , Polymer). Evaluation yielded mean absolute percent differences 28%, 12%, 10% (300), DOC, respectively. Application multi‐year OLCI captured, first time, coupled impact seasonal transitions, wind regimes, freshwater inputs, anthropogenic disturbances, hydrological extremes (both intense precipitation droughts) on quality at ecosystem scale. Results have important implications improved predictions complex urban−estuary systems.

Language: Английский

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Driving factors of colored dissolved organic matter dynamics across a complex urbanized estuary

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 921, P. 171083 - 171083

Published: Feb. 20, 2024

The role of estuaries in sourcing and transforming dissolved organic matter - the largest reservoir carbon ocean still presents many unknowns for coastal biogeochemical cycles, is further complicated by increasing human pressures a changing climate. Here, we examined major drivers colored (CDOM) dynamics Long Island Sound (LIS), heavily urbanized estuary National Significance with storied water quality past. A comprehensive new optical dataset, including measurements CDOM absorption fluorescence signatures, was integrated biological hydrological to capture spatiotemporal heterogeneities LIS, its urban-to-rural gradient, dynamic river mouths, blue ecosystems across seasons, following episodic storm events, over five years. Results reveal longitudinal gradients both DOM amount quality. While carbon-rich humic terrigenous dominant riverine-influenced Central Eastern an uncoupling between (aCDOM) (DOC) concentration Western stronger correlation Chlorophyll-a, indicated increased autochthonous production. Closer New York City urban core, aCDOM highly correlated turbidity, consistent wastewater influences. Fluorescence PARAFAC analysis provided strong evidence seasonal processing related summertime photochemical degradation humic-like components shoulder-season microbial processing. Riverine export influenced discharge amount, residence time, wetlands acting as additional sources strongly aromatic matter. These allowed us assess how hydrologic, biological, anthropogenic processes impact and, subsequently, variability trophic status this complex estuary, implications management policy. discussed here are applicable beyond globally face similar forcings.

Language: Английский

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Co-occurrence of Aquatic Heatwaves with Atmospheric Heatwaves, Low Dissolved Oxygen, and Low pH Events in Estuarine Ecosystems

Estuaries and Coasts, Journal Year: 2021, Volume and Issue: 45(3), P. 707 - 720

Published: Sept. 28, 2021

Language: Английский

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Chlorophyll dynamics from Sentinel-3 using an optimized algorithm for enhanced ecological monitoring in complex urban estuarine waters

International Journal of Applied Earth Observation and Geoinformation, Journal Year: 2023, Volume and Issue: 118, P. 103223 - 103223

Published: Feb. 28, 2023

Urban estuaries are dynamic environments that hold high ecological and economic value. Yet, their optical complexity hinders accurate satellite retrievals of important biogeochemical variables, such as chlorophyll-a (Chl-a) biomass. Approaches based on a limited number spectral bands often fail to capture seasonal transitions sharp spatial gradients in estuarine Chl-a concentrations, inhibiting integration data into water quality monitoring conservation programs. We propose novel approach utilizes the wide range information captured by Ocean Land Color Instrument (OLCI) retrieve Chl-a. To validate our approach, we used measurements Long Island Sound (LIS), highly urbanized estuary increasingly susceptible anthropogenic stressors climate change. Hyperspectral remote sensing reflectance (Rrs) representing spatiotemporal diversity LIS were assess ideal atmospheric correction for OLCI develop multi-spectral multiple linear regression (MS-MLR) algorithm. POLYMER derived Rrs proved be preferred approach. Evaluation MS-MLR performance retrieving with situ showed good agreement field measurements. Application OLCI-retrieved significant improvement (20%-30%) common error metrics relative other algorithms assessed. The successfully cycles concentration. this method urban coasts enables accurate, resolution observations at ecosystem scale across conditions, needed management efforts.

Language: Английский

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Physical and Biological Controls on Short-Term Variations in Dissolved Oxygen in Shallow Waters of a Large Temperate Estuary

Estuaries and Coasts, Journal Year: 2024, Volume and Issue: 47(6), P. 1456 - 1474

Published: July 1, 2024

Language: Английский

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CircArid4b: A novel circular RNA regulating antibacterial response during hypoxic stress via apoptosis in yellow catfish (Pelteobagrus fulvidraco)

Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology, Journal Year: 2025, Volume and Issue: 289, P. 110121 - 110121

Published: Jan. 7, 2025

Language: Английский

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Base-flow sampling to enhance understanding of the groundwater flow component of nitrogen loading in small watersheds draining into Long Island Sound

Data report, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

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Nitrate Loads and Concentrations From Forested Watersheds and Implications for Long Island Sound

Journal of Geophysical Research Biogeosciences, Journal Year: 2025, Volume and Issue: 130(4)

Published: March 27, 2025

Abstract Reduction in point sources of nitrogen has led to improvement water quality the Long Island Sound (LIS) since 2000, but changes nonpoint are less clear. A significant yet poorly quantified source is forested landscape. Because a large proportion LIS basin forested, even small areal inputs from landscape have cumulative effect on loading LIS. Atmospheric deposition, primary landscapes basin, been declining for several decades. However, export streams does not necessarily mirror deposition. To assess forest LIS, we estimated annual average concentrations and fluxes nitrate 17 watersheds near basin. Average flow‐normalized nitrate‐nitrogen ranged than 0.05–0.43 mg per liter among all sites; yields 0.45 4.3 kg hectare. Flow‐normalized between years 1991–2021 did monotonically increase or decrease at most watersheds. Where determined, other major N species generally had comparable magnitude trends. Based analyzed this study, areas responding uniformly continued decline atmospheric The variability sites may indicate that local‐scale factors exert substantial influence over trends exports. One watershed increasing development showed an trend nitrate, dissolved organic nitrogen.

Language: Английский

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Links between high fecal indicator bacteria levels and rain, wind, and tides at Connecticut beaches

Ocean & Coastal Management, Journal Year: 2025, Volume and Issue: 266, P. 107664 - 107664

Published: April 7, 2025

Language: Английский

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Impacts and uncertainties of climate-induced changes in watershed inputs on estuarine hypoxia

Biogeosciences, Journal Year: 2023, Volume and Issue: 20(10), P. 1937 - 1961

Published: May 26, 2023

Abstract. Multiple climate-driven stressors, including warming and increased nutrient delivery, are exacerbating hypoxia in coastal marine environments. Within watersheds, environmental managers particularly interested climate impacts on terrestrial processes, which may undermine the efficacy of management actions designed to reduce eutrophication consequent low-oxygen conditions receiving waters. However, substantial uncertainty accompanies application Earth system model (ESM) projections a regional modeling framework when quantifying future changes estuarine due change. In this study, two downscaling methods applied multiple ESMs used force independent watershed models for Chesapeake Bay, large coastal-plain estuary eastern United States. The projected then coupled 3-D hydrodynamic–biogeochemical project hypoxia, with particular emphasis projection uncertainties. Results indicate that all three factors (ESM, method, model) found contribute substantially associated choice ESM being largest contributor. Overall, absence actions, there is high likelihood change will expand by 2050 relative 1990s baseline period; however, increase quite small (4 %) because only climate-induced inputs considered not those itself. also demonstrate attainment established reduction targets annual about 50 % compared 1990s. Given these estimates, it virtually certain fully implemented reducing excess loadings outweigh increases driven runoff.

Language: Английский

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