Impacts of Marine Heatwaves on Subsurface Temperatures and Dissolved Oxygen in the Chesapeake Bay

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

Published: Feb. 26, 2024

Abstract Subsurface impacts associated with Marine Heatwaves (MHWs) in estuaries are not well understood, largely due to data scarcity. Using over three decades (1986–2021) of observations from several monitoring programs, this study investigates subsurface temperature and dissolved oxygen (DO) anomalies surface MHWs the Chesapeake Bay (CB). Seasonal variability followed a simple 1‐D response heating downward heat transport diffusion controlled by seasonally variable stratification mixing. Two distinct regimes were found: thermally stratified spring‐summer regime, when positive confined mixed layer (SML); homogeneous fall‐winter regime. Additionally, (subsurface) temperatures elevated for months (days weeks) before after MHWs, indicating individual events shorter than timescales temperatures. A SML budget identified air‐estuary flux changes as leading driver MHW onsets declines, latent being dominant term. DO anomaly patterns more complex, considerable along‐channel gradients. Notable decreases (1–4 mg L −1 ) primarily occurred winter/spring below SML, hypoxic zone expanded spring through fall. Only small fraction these could be attributed temperature‐induced solubility changes, demonstrating that other physical and/or biogeochemical processes dominate during events. In CB, concurrent low persistent high compound on valuable ecosystem, event likely exacerbated climate change.

Language: Английский

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Analysis of estuarine marine heatwaves in an upwelling system: The Ría de Arousa as a case study

Global and Planetary Change, Journal Year: 2025, Volume and Issue: unknown, P. 104776 - 104776

Published: Feb. 1, 2025

Language: Английский

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Temperature amplification and marine heatwave alteration in shallow coastal bays

Frontiers in Marine Science, Journal Year: 2023, Volume and Issue: 10

Published: Sept. 7, 2023

Shallow coastal ecosystems are threatened by marine heatwaves, but few long-term records exist to quantify these heatwaves. Here, 40-year of measured water temperature were constructed for a site in system shallow bays with documented heatwave impacts and nearby ocean site; available gridded sea-surface datasets the region also examined. Water temperatures at both sites increased significantly though bay consistently 3-4°C hotter summer colder winter more variable overall, differences not captured high-resolution datasets. There was considerable overlap events sites. Annual exposure similar while annual intensity higher owing high variance daily anomaly there. Event frequency rate about 1 event/decade. Future simulations indicate all metrics increase, as do days above 28°C, heat stress threshold seagrass. Ocean on U.S. mid-Atlantic margin have rarely exceeded this threshold, commonly do, allowing exchange provide thermal relief ecosystems. This will changed 2100, creating environment that threatens seagrass communities systems. Documenting such change requires development

Language: Английский

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Marine heatwaves in shallow coastal ecosystems are coupled with the atmosphere: Insights from half a century of daily in situ temperature records

Frontiers in Climate, Journal Year: 2022, Volume and Issue: 4

Published: Nov. 3, 2022

Marine heatwaves (MHWs) are extreme ocean temperature events that can have wide-ranging and pervasive effects on marine species ecosystems. However, studies of MHW characteristics drivers primarily focus open-ocean environments, rather than the nearshore coastal (<10 km from coast, <50 m depth). This is despite waters sustaining significant commercial, recreational, customary fisheries aquaculture activities highly susceptible to impacts MHWs. The two longest (>50 year) daily in situ records Southern Hemisphere used investigate variability, drivers, trends MHWs shallow water ecosystems (SWMEs). Located at northern southern limits New Zealand, both locations experience an average three annually, with exposed coastline site generally being longer duration but less intense those observed within semi-enclosed harbor site. Observed timescales similar synoptic weather systems (9–13 days) most during Austral summer little seasonality frequency or duration. An investigation co-occurring offshore suggests (e.g., harbors, estuaries) more closely coupled local atmospheric conditions likely a occurring coastlines. Composite analysis using reanalysis product elucidates specific pressure systems, wind speed latent heat fluxes important contributing factors generation decline SWMEs. Investigation long-term properties revealed increase annual days decrease maximum intensity consistent broad-scale warming previously documented these stations, differences related changes large-scale circulation patterns around Zealand. Our results highlight importance data for ocean, role forcing modulating occurrence SWMEs, which cause decoupling dynamics surrounding shelf sea.

Language: Английский

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Effects of basin-scale climate modes and upwelling on nearshore marine heatwaves and cold spells in the California Current

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: July 31, 2023

Marine heatwaves and cold spells (MHWs/MCSs) have been observed to be increasing globally in frequency intensity based on satellite remote sensing continue pose a major threat marine ecosystems worldwide. Despite this, there are limited in-situ observational studies the very shallow nearshore region, particularly Eastern Boundary Current Upwelling Systems (EBUS). We analyzed unique dataset collected waters along central California spanning more than four decades (1978-2020) assessed links with basin-scale climate modes [Pacific Decadal Oscillation (PDO) El Niño (MEI)] regional-scale wind-driven upwelling. found no significant increase/decrease MHW/MCS frequency, duration, or over last decades, but did observe considerable interannual variability linked modes. Additionally, was decrease both occurrence during upwelling season, initiation of individual MHWs/MCSs coincided anomalous Most notably, co-occurrence warm (cold) phases PDO MEI negative (positive) anomalies strongly enhanced relative positive (negative) temperature MHW (MCS) days. Collectively, forcing play key role predicting extreme events shaping resilience EBUS.

Language: Английский

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Application of Deep Learning for Classification of Intertidal Eelgrass from Drone-Acquired Imagery

Remote Sensing, Journal Year: 2023, Volume and Issue: 15(9), P. 2321 - 2321

Published: April 28, 2023

Shallow estuarine habitats are globally undergoing rapid changes due to climate change and anthropogenic influences, resulting in spatiotemporal shifts distribution habitat extent. Yet, scientists managers do not always have rapidly available data track real-time. In this study, we apply a novel state-of-the-art image segmentation machine learning technique (DeepLab) two years of high-resolution drone-based imagery marine flowering plant species (eelgrass, temperate seagrass). We the model eelgrass (Zostera marina) meadows Morro Bay estuary, California, an estuary that has undergone large declines subsequent recovery seagrass last decade. The accurately classified across range conditions sizes from meadow-scale small-scale patches less than meter size. recall, precision, F1 scores were 0.954, 0.723, 0.809, respectively, when using human-annotated training random assessment points. All our accuracy values comparable or demonstrated greater other models for similar systems. This study demonstrates potential advanced methods support active monitoring analysis dynamics images, framework likely applicable ecosystems globally, one can provide quantitative accurate long-term management strategies seek protect these vital ecosystems.

Language: Английский

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Vertical structure of subsurface marine heatwaves in a shallow nearshore upwelling system

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: Feb. 21, 2025

Language: Английский

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Spatial Variability of Marine Heatwaves in the Chesapeake Bay

Estuaries and Coasts, Journal Year: 2025, Volume and Issue: 48(4)

Published: May 23, 2025

Language: Английский

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Characterising intertidal sediment temperature gradients in estuarine systems

Estuarine Coastal and Shelf Science, Journal Year: 2024, Volume and Issue: unknown, P. 108968 - 108968

Published: Sept. 1, 2024

Language: Английский

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Climate change and variability drive increasing exposure of marine heatwaves across US estuaries

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: March 6, 2025

Marine heatwaves (MHWs) are among the greatest threats to marine ecosystems, and while substantial advances have been made in oceanic MHWs, little is known about estuarine MHWs. Utilizing a temperature dataset spanning over two decades 54 stations distributed across 20 estuaries United States National Estuarine Research Reserve System, we present comprehensive analysis of MHW characteristics trends. Long-term climate-change-driven warming driving more frequent MHWs along East Coast, if trends continue, this region will be state for ~ 1/3 year by end century. In contrast, vast majority West Coast showed no trends, highlighting potential future thermal refugia. The was strongly influenced climate variability through enhancement/suppression during different phases modes, suggesting long-term predictability potential. These results can provide guidance management actions planning these critical environments.

Language: Английский

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