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2023

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Articles 91 - 120 of 155

Full-Text Articles in Oceanography

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran Jan 2023

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …

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Hydrodynamics And Sediment Transport In The Tidally Influenced James River, Ollie Gilchrest, Rip Hale Jan 2023

Hydrodynamics And Sediment Transport In The Tidally Influenced James River, Ollie Gilchrest, Rip Hale

The Graduate School Posters

The tidally influenced James River is an important economic, ecologic, and cultural resource for VA residents. Tidal rivers have been historically understudied, however they are critical transition zones, the dynamics of which have implications for freshwater supply and sediment trapping. Globally, estimates suggest that >30% of fluvial sediment is trapped in the tidal zone, the location and dynamics of which are actively changing due to sea level rise and saltwater encroachment. In addition, analysis of historical water levels on the James River has shown a decrease in the tidal range since 1940. The present study combines >1-year’s worth of hydrographic …

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Dust Deposition To The Bermuda Region: A Comparison Of Estimates Using Seasonally-Resolved Measurements Of Aluminum In Water-Column, Aerosol, And Rain Samples, Tara Williams, Peter Sedwick, Bettina Sohst, Joe Resing, Kristen Buck, Salvatore Caprara, Rod Johnson, Dan Ohnemus, Ben Twining, Alessandro Tagliabue Jan 2023

Dust Deposition To The Bermuda Region: A Comparison Of Estimates Using Seasonally-Resolved Measurements Of Aluminum In Water-Column, Aerosol, And Rain Samples, Tara Williams, Peter Sedwick, Bettina Sohst, Joe Resing, Kristen Buck, Salvatore Caprara, Rod Johnson, Dan Ohnemus, Ben Twining, Alessandro Tagliabue

College of Sciences Posters

Dust deposition is a major source of bioactive trace elements to the surface ocean, yet this flux remains difficult to constrain. Previously, time-averaged dust flux has been estimated using surface ocean dissolved aluminum (DAl) concentrations, assumed values for aerosol aluminum solubility (%AlS), and the residence time of DAl in the surface mixed layer (SML). We apply this method to estimate dust deposition in the Bermuda Atlantic Time-series Study (BATS) region using water-column DAl data from cruises in 2019, which is compared with direct flux estimates from contemporaneous measurements of aluminum in aerosols and rain collected on Bermuda. Seasonal …

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A Methodology For Statistical Mean Wave Climate Regime Characterisation In Oceanic Islands: The Case Of The Southern Coast Of Tenerife, Emilio Megías, Manuel García-Román Jan 2023

A Methodology For Statistical Mean Wave Climate Regime Characterisation In Oceanic Islands: The Case Of The Southern Coast Of Tenerife, Emilio Megías, Manuel García-Román

Journal of Marine Science and Technology–Taiwan

Oceanic islands of volcanic origin tend to have peculiar characteristics, such as: exposure to many wave directions; grouping in archipelagos; steep coastal slopes; and small coastal shelves. All these features require certain considerations in wave climate studies. These types of studies, when wave spectra are not available and have to be performed with parametric data, can be unreliable without an adequate systematic treatment. In this work we propose a methodology consisting of pre-classification according to the peak period and subsequent separation into different sectors according to the geographical fetch. The island of Tenerife is the case study, and in particular …

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Methane Emissions In Seagrass Meadows As A Small Offset To Carbon Sequestration, Yvonne Y. Y. Yau, Gloria Reithmaier, Caludia Majtényi-Hill, Oscar Serrano, Nerea Piñeiro-Juncal, Martin Dahl, Miguel A. Mateo, Stefano Bonaglia, Isaac R. Santos Jan 2023

Methane Emissions In Seagrass Meadows As A Small Offset To Carbon Sequestration, Yvonne Y. Y. Yau, Gloria Reithmaier, Caludia Majtényi-Hill, Oscar Serrano, Nerea Piñeiro-Juncal, Martin Dahl, Miguel A. Mateo, Stefano Bonaglia, Isaac R. Santos

Research outputs 2022 to 2026

Seagrass meadows are effective carbon sinks due to high primary production and sequestration in sediments. However, methane (CH4) emissions can partially counteract their carbon sink capacity. Here, we measured diffusive sediment-water and sea-air CO2 and CH4 fluxes in a coastal embayment dominated by Posidonia oceanica in the Mediterranean Sea. High-resolution timeseries observations revealed large spatial and temporal variability in CH4 concentrations (2–36 nM). Lower sea-air CH4 emissions were observed in an area with dense seagrass meadows compared to patchy seagrass. A 6%−40% decrease of CH4 concentration in the surface water around noon indicates that photosynthesis likely limits CH4 fluxes. Sediments …

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Co-Designing A Multi-Criteria Approach To Ranking Hazards To And From Australia’S Emerging Offshore Blue Economy, Mischa P. Turschwell, Christopher J. Brown, Myriam Lacharité, Jess Melbourne-Thomas, Keith R. Hayes, Rodrigo H. Bustamante, Jeffrey M. Dambacher, Karen Evans, Pedro Fidelman, Darla H. Macdonald, Ingrid Van Putten, Graham Wood, Nagi Abdussamie, Mathilda Bates, Damien Blackwell, Steven D'Alessandro, Ian Dutton, Jessica A. Ericson, Christopher L. J. Frid, Carmel Mcdougall, Mary-Anne Lea, David Rissik, Rowan Trebilco, Elizabeth A. Fulton Jan 2023

Co-Designing A Multi-Criteria Approach To Ranking Hazards To And From Australia’S Emerging Offshore Blue Economy, Mischa P. Turschwell, Christopher J. Brown, Myriam Lacharité, Jess Melbourne-Thomas, Keith R. Hayes, Rodrigo H. Bustamante, Jeffrey M. Dambacher, Karen Evans, Pedro Fidelman, Darla H. Macdonald, Ingrid Van Putten, Graham Wood, Nagi Abdussamie, Mathilda Bates, Damien Blackwell, Steven D'Alessandro, Ian Dutton, Jessica A. Ericson, Christopher L. J. Frid, Carmel Mcdougall, Mary-Anne Lea, David Rissik, Rowan Trebilco, Elizabeth A. Fulton

Research outputs 2022 to 2026

A multi-sectoral assessment of risks can support the management and investment decisions necessary for emerging blue economy industries to succeed. Traditional risk assessment methods will be challenged when applied to the complex socio-ecological systems that characterise offshore environments, and when data available to support management are lacking. Therefore, there is a need for assessments that account for multiple sectors. Here we describe the development of an efficient method for an integrated hazard analysis that is a precursor to full risk assessments. Our approach combines diverse disciplinary expertise, expert elicitation and multi-criteria analysis to rank hazards, so it encompasses all types …

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Biophysical Interactions Control The Progression Of Harmful Algal Blooms In Chesapeake Bay: A Novel Lagrangian Particle Tracking Model With Mixotrophic Growth And Vertical Migration, Jilian Xiong, Jian Shen, Qubin Qin, Michelle C. Tomlinson, Yinglong J. Zhang, Xun Cai, Fei Yi, Linlin Cui, Margaret R. Mulholland Jan 2023

Biophysical Interactions Control The Progression Of Harmful Algal Blooms In Chesapeake Bay: A Novel Lagrangian Particle Tracking Model With Mixotrophic Growth And Vertical Migration, Jilian Xiong, Jian Shen, Qubin Qin, Michelle C. Tomlinson, Yinglong J. Zhang, Xun Cai, Fei Yi, Linlin Cui, Margaret R. Mulholland

OES Faculty Publications

Climate change and nutrient pollution contribute to the expanding global footprint of harmful algal blooms. To better predict their spatial distributions and disentangle biophysical controls, a novel Lagrangian particle tracking and biological (LPT-Bio) model was developed with a high-resolution numerical model and remote sensing. The LPT-Bio model integrates the advantages of Lagrangian and Eulerian approaches by explicitly simulating algal bloom dynamics, algal biomass change, and diel vertical migrations along predicted trajectories. The model successfully captured the intensity and extent of the 2020 Margalefidinium polykrikoides bloom in the lower Chesapeake Bay and resolved fine-scale structures of bloom patchiness, demonstrating a reliable …

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Interactions Of Bioactive Trace Metals In Shipboard Southern Ocean Incubation Experiments, Shannon M. Burns, Randelle M. Bundy, William Abbott, Zuzanna Abdala, Alexa R. Sterling, P. Dreux Chappell, Bethany D. Jenkins, Kristen N. Buck Jan 2023

Interactions Of Bioactive Trace Metals In Shipboard Southern Ocean Incubation Experiments, Shannon M. Burns, Randelle M. Bundy, William Abbott, Zuzanna Abdala, Alexa R. Sterling, P. Dreux Chappell, Bethany D. Jenkins, Kristen N. Buck

OES Faculty Publications

In the Southern Ocean, it is well‐known that iron (Fe) limits phytoplankton growth. Yet, other trace metals can also affect phytoplankton physiology. This study investigated feedbacks between phytoplankton growth and dissolved Fe, manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and cadmium (Cd) concentrations in Southern Ocean shipboard incubations. Three experiments were conducted in September–October 2016 near the West Antarctic Peninsula: Incubations 1 and 3 offshore in the Antarctic Circumpolar Current, and Incubation 2 inshore in Bransfield Strait. Additions of Fe and/or vitamin B12 to inshore and offshore waters were employed and allowed assessment of metal (M) …

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Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti Jan 2023

Nitrite Cycling In The Primary Nitrite Maxima Of The Eastern Tropical North Pacific, Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, Karen L. Casciotti

OES Faculty Publications

The primary nitrite maximum (PNM) is a ubiquitous feature of the upper ocean, where nitrite accumulates in a sharp peak at the base of the euphotic zone. This feature is situated where many chemical and hydrographic properties have strong gradients and the activities of several microbial processes overlap. Near the PNM, four major microbial processes are active in nitrite cycling: ammonia oxidation, nitrite oxidation, nitrate reduction and nitrite uptake. The first two processes are mediated by the nitrifying archaeal/bacterial community, while the second two processes are primarily conducted by phytoplankton. The overlapping spatial habitats and substrate requirements for these microbes …

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The Importance Of Winter Dinoflagellate Blooms In Chesapeake Bay— A Missing Link In Bay Productivity, Nicole C. Millette, Sophie Clayton, Margaret R. Mulholland, Leah Gibala-Smith, Michael Lane Jan 2023

The Importance Of Winter Dinoflagellate Blooms In Chesapeake Bay— A Missing Link In Bay Productivity, Nicole C. Millette, Sophie Clayton, Margaret R. Mulholland, Leah Gibala-Smith, Michael Lane

OES Faculty Publications

It is widely assumed that phytoplankton abundance and productivity decline during temperate winters because of low irradiance and temperatures. However, winter phytoplankton blooms commonly occur in temperate estuaries, but they are often undocumented because of reduced water quality monitoring in winter. The small body of in situ work that has been done on winter blooms suggests they can be of enormous consequence to ecosystems. However, because monitoring is often reduced or stopped altogether during winter, it is unclear how widespread these blooms are or how long they can last. We analyzed an over 30-year record of monthly phytoplankton monitoring samples …

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Providing A Framework For Seagrass Mapping In United States Coastal Ecosystems Using High Spatial Resolution Satellite Imagery, Megan M. Coffer, David D. Graybill, Peter J. Whitman, Blake A. Schaeffer, Wilson B. Salls, Richard C. Zimmerman, Victoria Hill, Marie Cindy Lebrasse, Jiang Li, Darryl J. Keith, James Kaldy, Phil Colarusso, Gary Raulerson, David Ward, W. Judson Kenworthy Jan 2023

Providing A Framework For Seagrass Mapping In United States Coastal Ecosystems Using High Spatial Resolution Satellite Imagery, Megan M. Coffer, David D. Graybill, Peter J. Whitman, Blake A. Schaeffer, Wilson B. Salls, Richard C. Zimmerman, Victoria Hill, Marie Cindy Lebrasse, Jiang Li, Darryl J. Keith, James Kaldy, Phil Colarusso, Gary Raulerson, David Ward, W. Judson Kenworthy

OES Faculty Publications

Seagrasses have been widely recognized for their ecosystem services, but traditional seagrass monitoring approaches emphasizing ground and aerial observations are costly, time-consuming, and lack standardization across datasets. This study leveraged satellite imagery from Maxar's WorldView-2 and WorldView-3 high spatial resolution, commercial satellite platforms to provide a consistent classification approach for monitoring seagrass at eleven study areas across the continental United States, representing geographically, ecologically, and climatically diverse regions. A single satellite image was selected at each of the eleven study areas to correspond temporally to reference data representing seagrass coverage and was classified into four general classes: land, seagrass, no …

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Potential Interactions Between Diatoms And Bacteria Are Shaped By Trace Element Gradients In The Southern Ocean, Alexa R. Sterling, Laura Z. Holland, Randelle M. Bundy, Shannon M. Burns, Kristen N. Buck, P. Dreux Chappell, Bethany D. Jenkins Jan 2023

Potential Interactions Between Diatoms And Bacteria Are Shaped By Trace Element Gradients In The Southern Ocean, Alexa R. Sterling, Laura Z. Holland, Randelle M. Bundy, Shannon M. Burns, Kristen N. Buck, P. Dreux Chappell, Bethany D. Jenkins

OES Faculty Publications

The growth of diatoms in the Southern Ocean, especially the region surrounding the West Antarctic Peninsula, is frequently constrained by low dissolved iron and other trace metal concentrations. This challenge may be overcome by mutualisms between diatoms and co-occurring associated bacteria, in which diatoms produce organic carbon as a substrate for bacterial growth, and bacteria produce siderophores, metal-binding ligands that can supply diatoms with metals upon uptake as well as other useful secondary compounds for diatom growth like vitamins. To examine the relationships between diatoms and bacteria in the plankton (diatom) size class (> 3 mu m), we sampled both …

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Atmospheric Input And Seasonal Inventory Of Dissolved Iron In The Sargasso Sea: Implications For Iron Dynamics In Surface Waters Of The Subtropical Ocean, Peter N. Sedwick, Bettina M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, L. E. Sofen, A. Tagliabue, B. S. Twining, Tara E. Williams Jan 2023

Atmospheric Input And Seasonal Inventory Of Dissolved Iron In The Sargasso Sea: Implications For Iron Dynamics In Surface Waters Of The Subtropical Ocean, Peter N. Sedwick, Bettina M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, L. E. Sofen, A. Tagliabue, B. S. Twining, Tara E. Williams

OES Faculty Publications

Constraining the role of dust deposition in regulating the concentration of the essential micronutrient iron in surface ocean waters requires knowledge of the flux of seawater-soluble iron in aerosols and the replacement time of dissolved iron (DFe) in the euphotic zone. Here we estimate these quantities using seasonally resolved DFe data from the Bermuda Atlantic Time-series Study region and weekly-scale measurements of iron in aerosols and rain from Bermuda during 2019. In response to seasonal changes in vertical mixing, primary production and dust deposition, surface DFe concentrations vary from ∼0.2 nM in early spring to >1 nM in late summer, …

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Five Years Measuring The Muck: Evaluating Interannual Variability Of Nutrient Loads From Tidal Flooding, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt Jan 2023

Five Years Measuring The Muck: Evaluating Interannual Variability Of Nutrient Loads From Tidal Flooding, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt

OES Faculty Publications

Due to sea level rise, tidal flooding is now common in low-lying coastal systems around the world. Yet, the contribution of tidal flooding to non-point source nutrient loads and their impact on the quality of adjacent waters remains poorly constrained. Here, we quantified dissolved nutrient loading and Enterococcus abundance during annual autumnal king tides (i.e., perigean spring tides), between 2017 and 2021, in a sub-watershed of the lower Chesapeake Bay. To calculate nutrient loading from tidal flooding, we used geospatial inundation depths from a street-level hydrodynamic model to estimate floodwater volumes during each of the five sampling events and the …

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Sediment Delivery To Sustain The Ganges-Brahmaputra Delta Under Climate Change And Anthropogenic Impacts, Jessica L. Raff, Steven L. Goodbred Jr., Jennifer L. Pickering, Ryan S. Sincavage, John C. Ayers, Md. Saddam Hossain, Carol A. Wilson, Chris Paola, Michael S. Steckler, Dhiman R. Mondal, Jean-Louis Grimaud, Celine Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Humayun Akhter, Brandee N. Carlson, Elizabeth L. Chamberlain, Meagan Dejter, Jonathan M. Gilligan, Richard P. Hale, Mahfuzur R. Khan, Md. Golam Muktadir, Md. Munsur Rahman, Lauren A. Williams Jan 2023

Sediment Delivery To Sustain The Ganges-Brahmaputra Delta Under Climate Change And Anthropogenic Impacts, Jessica L. Raff, Steven L. Goodbred Jr., Jennifer L. Pickering, Ryan S. Sincavage, John C. Ayers, Md. Saddam Hossain, Carol A. Wilson, Chris Paola, Michael S. Steckler, Dhiman R. Mondal, Jean-Louis Grimaud, Celine Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Humayun Akhter, Brandee N. Carlson, Elizabeth L. Chamberlain, Meagan Dejter, Jonathan M. Gilligan, Richard P. Hale, Mahfuzur R. Khan, Md. Golam Muktadir, Md. Munsur Rahman, Lauren A. Williams

OES Faculty Publications

The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers’ ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to …

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A Global Comparison Of Marine Chlorophyll Variability Observed In Eulerian And Lagrangian Perspectives, Angela M. Kuhn, Matthew Mazloff, Stephanie Dutkiewicz, Oliver Jahn, Sophie Clayton, Tatiana Rynearson, Andrew D. Barton Jan 2023

A Global Comparison Of Marine Chlorophyll Variability Observed In Eulerian And Lagrangian Perspectives, Angela M. Kuhn, Matthew Mazloff, Stephanie Dutkiewicz, Oliver Jahn, Sophie Clayton, Tatiana Rynearson, Andrew D. Barton

OES Faculty Publications

The California Current System is a diatom‐dominated region characterized by seasonal coastal upwelling and additional elevated mesoscale activity. Cyclonic mesoscale eddies in the region trap productive coastal waters with their planktonic communities and transport them offshore with limited interaction with surrounding waters, effectively acting as natural mesocosms, where phytoplankton populations undergo ecological succession as eddies age. This study examines diatom community composition within two mesoscale cyclonic eddies that formed in the same region of the California Current System 2 months apart and in the California Current waters surrounding them. The diatom communities were analyzed in the context of shifting environmental …

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Systemic Analyses Of Radiocarbon Ages Of Coexisting Planktonic Foraminifera, Jörg Lippold, Julia Gottschalk, Jean Lynch-Stieglitz, Matthew W. Schmidt, Sönke Szidat, Andre Bahr Jan 2023

Systemic Analyses Of Radiocarbon Ages Of Coexisting Planktonic Foraminifera, Jörg Lippold, Julia Gottschalk, Jean Lynch-Stieglitz, Matthew W. Schmidt, Sönke Szidat, Andre Bahr

OES Faculty Publications

We compare radiocarbon (14C) ages of coexisting planktonic foraminifera species from sediment cores VM12-107 and KNR166-2-26JPC from the Equatorial Atlantic Ocean for three time periods (Holocene, Heinrich Stadial 1, last glacial maximum). We find a maximum inter-species difference of 1200 14C yr. On average, the 14C ages deviate by ∼300 yr between Globigerinoides ruber and other species. In most cases, this exceeds the analytical uncertainty range of the measurements and thus renders the choice of species for generating age models as important as sample weight. While modern stratified water-column profiles imply an increase in 14C …

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Global Oceanic Diazotroph Database Version 2 And Elevated Estimate Of Global N2 Fixation, Zhibo Shao, Yangchun Xu, Hua Wang, Weicheng Luo, Lice Wang, Yuhong Huang, Nona Sheila R. Agawin, Ayaz Ahmed, Mar Benavides, Mikkel Bentzon-Tilia, Ilana Berman-Frank, Hugo Berthelot, Isabelle C. Biegala, Mariana B. Bif, Antonio Bode, Sophie Bonnet, Deborah A. Bronk, Mark V. Brown, Lisa Campbell, Ya-Wei Luo Jan 2023

Global Oceanic Diazotroph Database Version 2 And Elevated Estimate Of Global N2 Fixation, Zhibo Shao, Yangchun Xu, Hua Wang, Weicheng Luo, Lice Wang, Yuhong Huang, Nona Sheila R. Agawin, Ayaz Ahmed, Mar Benavides, Mikkel Bentzon-Tilia, Ilana Berman-Frank, Hugo Berthelot, Isabelle C. Biegala, Mariana B. Bif, Antonio Bode, Sophie Bonnet, Deborah A. Bronk, Mark V. Brown, Lisa Campbell, Ya-Wei Luo

OES Faculty Publications

Marine diazotrophs convert dinitrogen (N2) gas into bioavailable nitrogen (N), supporting life in the global ocean. In 2012, the first version of the global oceanic diazotroph database (version 1) was published. Here, we present an updated version of the database (version 2), significantly increasing the number of in situ diazotrophic measurements from 13 565 to 55 286. Data points for N2 fixation rates, diazotrophic cell abundance, and nifH gene copy abundance have increased by 184 %, 86 %, and 809 %, respectively. Version 2 includes two new data sheets for the nifH gene copy abundance of non-cyanobacterial …

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Impact Of Atmospheric Correction On Classification And Quantification Of Seagrass Density From Worldview-2 Imagery, Victoria J. Hill, Richard C. Zimmerman, Paul Bissett, David Kohler, Blake Schaeffer, Megan Coffer, Jiang Li, Kazi Aminul Islam Jan 2023

Impact Of Atmospheric Correction On Classification And Quantification Of Seagrass Density From Worldview-2 Imagery, Victoria J. Hill, Richard C. Zimmerman, Paul Bissett, David Kohler, Blake Schaeffer, Megan Coffer, Jiang Li, Kazi Aminul Islam

OES Faculty Publications

Mapping the seagrass distribution and density in the underwater landscape can improve global Blue Carbon estimates. However, atmospheric absorption and scattering introduce errors in space-based sensors’ retrieval of sea surface reflectance, affecting seagrass presence, density, and above-ground carbon (AGCseagrass) estimates. This study assessed atmospheric correction’s impact on mapping seagrass using WorldView-2 satellite imagery from Saint Joseph Bay, Saint George Sound, and Keaton Beach in Florida, USA. Coincident in situ measurements of water-leaving radiance (Lw), optical properties, and seagrass leaf area index (LAI) were collected. Seagrass classification and the retrieval of LAI were compared after empirical line …

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Isotopic Evidence For Sources Of Dissolved Carbon And The Role Of Organic Matter Respiration In The Fraser River Basin, Canada, Britta M. Voss, Timothy I. Eglinton, Bernhard Peucker-Ehrenbrink, Valier Galy, Susan Q. Lang, Cameron Mcintyre, Robert G.M. Spencer, Ekaterina Bulygina, Zhaohui Aleck Wang, Katherine A. Guay Jan 2023

Isotopic Evidence For Sources Of Dissolved Carbon And The Role Of Organic Matter Respiration In The Fraser River Basin, Canada, Britta M. Voss, Timothy I. Eglinton, Bernhard Peucker-Ehrenbrink, Valier Galy, Susan Q. Lang, Cameron Mcintyre, Robert G.M. Spencer, Ekaterina Bulygina, Zhaohui Aleck Wang, Katherine A. Guay

OES Faculty Publications

Sources of dissolved and particulate carbon to the Fraser River system vary significantly in space and time. Tributaries in the northern interior of the basin consistently deliver higher concentrations of dissolved organic carbon (DOC) to the main stem than other tributaries. Based on samples collected near the Fraser River mouth throughout 2013, the radiocarbon age of DOC exported from the Fraser River does not change significantly across seasons despite a spike in DOC concentration during the freshet, suggesting modulation of heterogeneous upstream chemical and isotopic signals during transit through the river basin. Dissolved inorganic carbon (DIC) concentrations are highest in …

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Sea Ice Formation, Glacial Melt And The Solubility Pump Boundary Conditions In The Ross Sea, Brice Loose, Sharon Stammerjohn, Peter Sedwick, Stephen Ackley Jan 2023

Sea Ice Formation, Glacial Melt And The Solubility Pump Boundary Conditions In The Ross Sea, Brice Loose, Sharon Stammerjohn, Peter Sedwick, Stephen Ackley

OES Faculty Publications

Seasonal formation of Dense Shelf Water (DSW) in the Ross Sea is a direct precursor to Antarctic Bottom Water, which fills the deep ocean with atmospheric gases in what composes the southern limb of the solubility pump. Measurements of seawater noble gas concentrations during katabatic wind events in two Ross Sea polynyas reveal the physical processes that determine the boundary value properties for DSW. This decomposition reveals 5–6 g kg−1 of glacial meltwater in DSW and sea-ice production rates of up to 14 m yr−1 within the Terra Nova Bay polynya. Despite winds upwards of 35 m s …

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The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman Jan 2023

The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman

OES Faculty Publications

Seagrasses are foundation species that provide ecosystem functions and services, including increased biodiversity, sediment retention, carbon sequestration, and fish nursery habitat. However, anthropogenic stressors that reduce water quality, impose large-scale climate changes, and amplify weather patterns, such as marine heatwaves, are altering seagrass meadow configurations. Quantifying large-scale trends in seagrass distributions will help evaluate the impacts of climate drivers on their functions and services. Here, we quantified spatiotemporal dynamics in abundances and configurations of intertidal and shallow subtidal seagrass (Zostera muelleri) meadows in 20 New Zealand (NZ) estuaries that span a 5-year period (mid/late 2016–early 2022) just before, …

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An Update On The Influence Of Natural Climate Variability And Anthropogenic Climate Change On Tropical Cyclones, Suzana J. Camargo, Hiroyuki Murakami, Nadia Bloemendaal, Savin S. Chand, Medha S. Deshpande, Christian Dominguez-Sarmiento, Juan Jesús González-Alemán, Thomas R. Knutson, I. I. Lin, Il- Ju Moon, Christina M. Patricola, Kevin A. Reed, Malcolm J. Roberts, Enrico Scoccimarro, Chi Yung Tam, Elizabeth J. Wallace, Liguang Wu, Yohei Yamada, Wei Zhang, Haikun Zhao Jan 2023

An Update On The Influence Of Natural Climate Variability And Anthropogenic Climate Change On Tropical Cyclones, Suzana J. Camargo, Hiroyuki Murakami, Nadia Bloemendaal, Savin S. Chand, Medha S. Deshpande, Christian Dominguez-Sarmiento, Juan Jesús González-Alemán, Thomas R. Knutson, I. I. Lin, Il- Ju Moon, Christina M. Patricola, Kevin A. Reed, Malcolm J. Roberts, Enrico Scoccimarro, Chi Yung Tam, Elizabeth J. Wallace, Liguang Wu, Yohei Yamada, Wei Zhang, Haikun Zhao

OES Faculty Publications

A substantial number of studies have been published since the Ninth International Workshop on Tropical Cyclones (IWTC-9) in 2018, improving our understanding of the effect of climate change on tropical cyclones (TCs) and associated hazards and risks. These studies have reinforced the robustness of increases in TC intensity and associated TC hazards and risks due to anthropogenic climate change. New modeling and observational studies suggested the potential influence of anthropogenic climate forcings, including greenhouse gases and aerosols, on global and regional TC activity at the decadal and century time scales. However, there are still substantial uncertainties owing to model uncertainty …

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Carbonate Chemistry And Carbon Sequestation Driven By Inorganic Carbon Outwelling From Mangroves And Saltmarshes, Gloria M. S. Reithmaier, Alex Cabral, Anirban Akhand, Matthew J. Bogard, Alberto V. Borges, Steven Bouillon, David J. Burdige, Mitchell Call, Nengwang Chen, Xiaogang Chen, Luiz C. Cotovicz Jr., Meagan J. Eagle, Erik Kristensen, Kevin D. Kroeger, Zeyang Lu, Damien T. Maher, J. Lucas Pérez-Lloréns, Raghab Ray, Pierre Taillardat, Joseph J. Tamborski, Rob C. Upstill-Goddard, Faming Wang, Zhaohui Aleck Wang, Kai Xiao, Yvonne Y.Y. Yau, Isaac R. Santos Jan 2023

Carbonate Chemistry And Carbon Sequestation Driven By Inorganic Carbon Outwelling From Mangroves And Saltmarshes, Gloria M. S. Reithmaier, Alex Cabral, Anirban Akhand, Matthew J. Bogard, Alberto V. Borges, Steven Bouillon, David J. Burdige, Mitchell Call, Nengwang Chen, Xiaogang Chen, Luiz C. Cotovicz Jr., Meagan J. Eagle, Erik Kristensen, Kevin D. Kroeger, Zeyang Lu, Damien T. Maher, J. Lucas Pérez-Lloréns, Raghab Ray, Pierre Taillardat, Joseph J. Tamborski, Rob C. Upstill-Goddard, Faming Wang, Zhaohui Aleck Wang, Kai Xiao, Yvonne Y.Y. Yau, Isaac R. Santos

OES Faculty Publications

Mangroves and saltmarshes are biogeochemical hotspots storing carbon in sediments and in the ocean following lateral carbon export (outwelling). Coastal seawater pH is modified by both uptake of anthropogenic carbon dioxide and natural biogeochemical processes, e.g., wetland inputs. Here, we investigate how mangroves and saltmarshes influence coastal carbonate chemistry and quantify the contribution of alkalinity and dissolved inorganic carbon (DIC) outwelling to blue carbon budgets. Observations from 45 mangroves and 16 saltmarshes worldwide revealed that >70% of intertidal wetlands export more DIC than alkalinity, potentially decreasing the pH of coastal waters. Porewater-derived DIC outwelling (81 ± 47 mmol m−2 …

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Acceleration Of U.S. Southeast And Gulf Coast Sea-Level Rise Amplified By Internal Climate Variability, Sönke Dangendorf, Noah Hendricks, Qiang Sun, John Klinck, Tal Ezer, Thomas Frederikse, Francisco M. Calafat, Thomas Wahl, Torbjörn E. Törnqvist Jan 2023

Acceleration Of U.S. Southeast And Gulf Coast Sea-Level Rise Amplified By Internal Climate Variability, Sönke Dangendorf, Noah Hendricks, Qiang Sun, John Klinck, Tal Ezer, Thomas Frederikse, Francisco M. Calafat, Thomas Wahl, Torbjörn E. Törnqvist

CCPO Publications

While there is evidence for an acceleration in global mean sea level (MSL) since the 1960s, its detection at local levels has been hampered by the considerable influence of natural variability on the rate of MSL change. Here we report a MSL acceleration in tide gauge records along the U.S. Southeast and Gulf coasts that has led to rates (>10 mm yr−1 since 2010) that are unprecedented in at least 120 years. We show that this acceleration is primarily induced by an ocean dynamic signal exceeding the externally forced response from historical climate model simulations. However, when the …

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Examining The Connectivity Of Antarctic Krill On The West Antarctic Peninsula: Implications For Pygoscelis Penguin Biogeography And Population Dynamics, Katherine L. Gallagher, Michael S. Dinniman, Heather J. Lynch Jan 2023

Examining The Connectivity Of Antarctic Krill On The West Antarctic Peninsula: Implications For Pygoscelis Penguin Biogeography And Population Dynamics, Katherine L. Gallagher, Michael S. Dinniman, Heather J. Lynch

CCPO Publications

Antarctic krill (Euphausia superba) are considered a keystone species for higher trophic level predators along the West Antarctic Peninsula (WAP) during the austral summer. The connectivity of these populations may play a critical role in predator biogeography, especially for central-place foragers such as the Pygoscelis penguins that breed along the WAP during the austral summer. Here, we used a physical ocean model to examine adult krill connectivity in this region using simulated krill with realistic diel vertical migration behaviors across four austral summers. Specifically, we examined krill connectivity around the Adélie gap, a 400 km long region along …

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The Response Of Sea Ice And High-Salinity Shelf Water In The Ross Ice Shelf Polynya To Cyclonic Atmosphere Circulations, Xiaoqiao Wang, Zhaoru Zhang, Michael S. Dinniman, Petteri Uotila, Xichen Li, Meng Zhou Jan 2023

The Response Of Sea Ice And High-Salinity Shelf Water In The Ross Ice Shelf Polynya To Cyclonic Atmosphere Circulations, Xiaoqiao Wang, Zhaoru Zhang, Michael S. Dinniman, Petteri Uotila, Xichen Li, Meng Zhou

CCPO Publications

Coastal polynyas in the Ross Sea are important source regions of high-salinity shelf water (HSSW) – the precursor of Antarctic Bottom Water that supplies the lower limb of the thermohaline circulation. Here, the response of sea ice production and HSSW formation to synoptic-scale and mesoscale cyclones was investigated for the Ross Ice Shelf Polynya (RISP) using a coupled ocean–sea ice–ice shelf model targeted on the Ross Sea. When synoptic-scale cyclones prevailed over RISP, sea ice production (SIP) increased rapidly by 20 %–30 % over the entire RISP. During the passage of mesoscale cyclones, SIP increased by about 2 times over …

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Integrating Human Dimensions In Decadal-Scale Prediction For Marine Social Ecological Systems: Lighting The Grey Zone, Jess Melbourne-Thomas, Desiree Tommasi, Marion Gehlen, Eugene J. Murphy, Jennifer Beckensteiner, Francisco Bravo, Tyler D. Eddy, Mibu Fischer, Elizabeth Fulton, Mayya Gogina, Eileen Hofmann, Maya Ito, Sara Mynott, Kelly Ortega-Cisneros, Anna N. Osiecka, Mark R. Payne, Romeo Saldívar-Lucio, Kim J.N. Scherrer Jan 2023

Integrating Human Dimensions In Decadal-Scale Prediction For Marine Social Ecological Systems: Lighting The Grey Zone, Jess Melbourne-Thomas, Desiree Tommasi, Marion Gehlen, Eugene J. Murphy, Jennifer Beckensteiner, Francisco Bravo, Tyler D. Eddy, Mibu Fischer, Elizabeth Fulton, Mayya Gogina, Eileen Hofmann, Maya Ito, Sara Mynott, Kelly Ortega-Cisneros, Anna N. Osiecka, Mark R. Payne, Romeo Saldívar-Lucio, Kim J.N. Scherrer

CCPO Publications

The dynamics of marine systems at decadal scales are notoriously hard to predict-hence references to this timescale as the "grey zone" for ocean prediction. Nevertheless, decadal-scale prediction is a rapidly developing field with an increasing number of applications to help guide ocean stewardship and sustainable use of marine environments. Such predictions can provide industry and managers with information more suited to support planning and management over strategic timeframes, as compared to seasonal forecasts or long-term (century-scale) predictions. The most significant advances in capability for decadal-scale prediction over recent years have been for ocean physics and biogeochemistry, with some notable advances …

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Interactive Effects Of Climate Change-Induced Range Shifts And Wind Energy Development On Future Economic Conditions Of The Atlantic Surfclam Fishery, Stephanie Stromp, Andrew M. Scheld, John M. Klinck, Daphne M. Munroe, Eric N. Powell, Roger Mann, Sarah Borsetti, Eileen E. Hofmann Jan 2023

Interactive Effects Of Climate Change-Induced Range Shifts And Wind Energy Development On Future Economic Conditions Of The Atlantic Surfclam Fishery, Stephanie Stromp, Andrew M. Scheld, John M. Klinck, Daphne M. Munroe, Eric N. Powell, Roger Mann, Sarah Borsetti, Eileen E. Hofmann

CCPO Publications

Rising water temperatures along the northeastern U.S. continental shelf have resulted in an offshore range shift of the Atlantic surfclam Spisula solidissima to waters still occupied by ocean quahogs Arctica islandica. Fishers presently are prohibited from landing both Atlantic surfclams and ocean quahogs in the same catch, thus limiting fishing to locations where the target species can be sorted on deck. Wind energy development on and around the fishing grounds will further restrict the fishery. A spatially explicit model of the Atlantic surfclam fishery (Spatially Explicit Fishery Economics Simulator) has the ability to simulate the consequences of fishery displacement …

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A Growth Model For Arctica Islandica: The Performance Of Tanaka And The Temptation Of Von Bertalanffy—Can The Two Coexist?, John M. Klinck, Eric N. Powell, Kathleen M. Hemeon, Jillian R. Sower, Daniel R. Hennen Jan 2023

A Growth Model For Arctica Islandica: The Performance Of Tanaka And The Temptation Of Von Bertalanffy—Can The Two Coexist?, John M. Klinck, Eric N. Powell, Kathleen M. Hemeon, Jillian R. Sower, Daniel R. Hennen

CCPO Publications

Organisms increase in size over time (age) due to excess assimilation over metabolic (respiration) energy demands. Most organisms reach a maximum size with increasing age as gain and loss balance. The von Bertalanffy length-at-age relationship, which is commonly used in fishery assessment calculations, imposes such a maximum size. However, some fished species, such as ocean quahogs, Arctica islandica, are long lived and continue to grow at old age. The Tanaka age-at-length relationship has continued growth at old age, but is rarely used in stock assessment models. A modified form of the von Bertalanffy model is presented, which mimics the …

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