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Articles 661 - 690 of 13989

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

A Collaborative Assessment Of Coastal Ocean Acidification Monitoring In Maine & Standard Operating Procedures And Best Practices For The Collection Of Continuous Ph Data In Coastal Marine Environments, Christopher W. Hunt, Curtis Bohlen, Mike Doan, Jeremy Miller Jan 2025

A Collaborative Assessment Of Coastal Ocean Acidification Monitoring In Maine & Standard Operating Procedures And Best Practices For The Collection Of Continuous Ph Data In Coastal Marine Environments, Christopher W. Hunt, Curtis Bohlen, Mike Doan, Jeremy Miller

Faculty Publications

The ‘Sensor Squad’ of the Maine Ocean Climate Collaborative is the product of a 2023 Maine Coastal and Marine Climate Action Fund grant to conduct “A two-year pilot project designed to address and overcome technological barriers to ocean acidification data collection, develop protocols to elevate quality assurance and ensure comparable data, and meet regularly to discuss project results and data compilation”. The Squad consists of representatives from Friends of Casco Bay (FOCB), Wells National Estuarine Research Reserve (WNERR), and the University of New Hampshire (UNH). This report is a summary of their efforts to assess affordable, repeatable means of continuously …


Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen Jan 2025

Tidal Flooding Contributes To Eutrophication: Constraining Nonpoint Source Inputs To An Urban Estuary Using A Data Driven Statistical Model, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, Sophie Clayton, Peter W. Bernhardt, Thomas R. Allen

OES Faculty Publications

In coastal urban areas, tidal flooding brings water carrying nutrients and particles back from land to estuarine and coastal waters. A statistical model to predict nutrient loads during tidal flooding events can help estimate nutrient loading from previous and future flooding events and adapt nutrient reduction strategies. We measured concentrations of dissolved inorganic nitrogen and phosphorus in floodwater at seven sentinel sites during 15 tidal flooding events from January 2019 to September 2020. The study area was the Lafayette River watershed in Norfolk, VA, USA, which is prone to tidal flooding and is predicted to experience more frequent and intense …


A Century Of Sediment Metal Contamination Of Mar Menor, Europe's Largest Saltwater Lagoon, Irene Alorda-Montiel, Valentí Rodellas, Ariane Arias-Ortiz, Albert Palanques, Andrea G. Bravo, Júlia Rodriguez-Puig, Aaron Alorda-Kleinglass, Carlos Green-Ruiz, Marc Diego-Feliu, Pere Masqué, Javier Gilabert, Jordi Garcia-Orellana Jan 2025

A Century Of Sediment Metal Contamination Of Mar Menor, Europe's Largest Saltwater Lagoon, Irene Alorda-Montiel, Valentí Rodellas, Ariane Arias-Ortiz, Albert Palanques, Andrea G. Bravo, Júlia Rodriguez-Puig, Aaron Alorda-Kleinglass, Carlos Green-Ruiz, Marc Diego-Feliu, Pere Masqué, Javier Gilabert, Jordi Garcia-Orellana

OES Faculty Publications

Coastal enclosed ecosystems, such as lagoons, are vulnerable to anthropogenic impacts because they favor the accumulation of contaminants from the surrounding watersheds, particularly in their sediments. Europe's largest saltwater lagoon, the Mar Menor (SE, Iberian Peninsula), is a highly impacted ecosystem and the first in the continent to be granted personhood rights. Based on a high-resolution spatial and temporal dataset, we present the historical reconstruction of metal contamination in this ecosystem during the last century. Our results highlight that sediment metal contamination has been mainly driven by the development of the mining industry in the nearby Sierra Minera de Cartagena-La …


Seasonality Of Submarine Groundwater Discharge Pathways In A Coastal Lagoon Revealed By Radium Isotopes: The Importance Of Porewater Exchange In Summer, Júlia Rodriguez-Puig, Valentí Rodellas, Marc Diego-Feliu, Andres Alcolea, Joaquín Jiménez-Martínez, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Francisco Pereira, Marisol Manzano, Javier Gilabert, Jordi Garcia-Orellana Jan 2025

Seasonality Of Submarine Groundwater Discharge Pathways In A Coastal Lagoon Revealed By Radium Isotopes: The Importance Of Porewater Exchange In Summer, Júlia Rodriguez-Puig, Valentí Rodellas, Marc Diego-Feliu, Andres Alcolea, Joaquín Jiménez-Martínez, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Francisco Pereira, Marisol Manzano, Javier Gilabert, Jordi Garcia-Orellana

OES Faculty Publications

Chemical fluxes supplied by Submarine Groundwater Discharge (SGD) can be relevant for coastal ecosystems, particularly lagoonal environments. An appropriate understanding of SGD requires constraining the magnitude and composition of its different pathways. However, the evaluation of SGD pathways is often limited to independent estimations, lacking a comprehensive understanding of the groundwater processes at play. In this study, we combined a Ra mass balance and hydrogeological modeling to simultaneously estimate different SGD pathways flowing into a coastal lagoon. We assessed water fluxes derived from fresh SGD, long-scale recirculation of seawater, and porewater exchange (PEX) into Mar Menor, a highly anthropized coastal …


Optimizing An Image Analysis Protocol For Ocean Particles In Focused Shadowgraph Imaging Systems, Huanqing Huang, Alexander B. Bochdansky Jan 2025

Optimizing An Image Analysis Protocol For Ocean Particles In Focused Shadowgraph Imaging Systems, Huanqing Huang, Alexander B. Bochdansky

OES Faculty Publications

A variety of imaging systems are in use in oceanographic surveys, and the opto-mechanical configurations have become highly sophisticated. However, much less consideration has been given to the accurate reconstruction of imaging data. To improve reconstruction of particles captured by Focused Shadowgraph Imaging (FoSI)—a system that excels at visualizing low-optical-density objects, we developed a novel object detection algorithm to process images with a resolution of ~ 12 μm per pixel. Suggested improvements to conventional edge-detection methods are relatively simple and time-efficient, and more accurately render the sizes and shapes of small particles ranging from 24 to 500 μm. In addition, …


Radon And Radium Isotope Signatures On A Massive Ice- And Permafrost-Rich Coastline, Lauren Kipp, Gwénaëlle Chaillou, Markus Kienast, Joseph Tamborski, Dustin Whalen Jan 2025

Radon And Radium Isotope Signatures On A Massive Ice- And Permafrost-Rich Coastline, Lauren Kipp, Gwénaëlle Chaillou, Markus Kienast, Joseph Tamborski, Dustin Whalen

OES Faculty Publications

Rapid warming in the Arctic is degrading permafrost and massive ice deposits, which releases solutes previously trapped in ice and frozen soils into groundwater, rivers, and the coastal ocean. Radium and radon isotopes are enriched in groundwaters and may therefore have utility as tracers for the delivery of permafrost-derived solutes to the ocean, particularly if massive ice- or permafrost-derived meltwaters have a distinct isotopic ratio. The ratio of radium isotopes within massive ice deposits can also be used to constrain timescales of ice segregation, as the four isotopes will decay with known rates once removed from contact with sediments. Here …


The Effect Of Temperature And Salinity On Margalefidinium Polykrikoides Group Iii Va, Usa Strain Growth, Eduardo Pérez-Vega, Margaret R. Mulholland, Katherine E. Crider, Kimberly E. Powell, P. Dreux Chappell, Alexander Bochdansky Jan 2025

The Effect Of Temperature And Salinity On Margalefidinium Polykrikoides Group Iii Va, Usa Strain Growth, Eduardo Pérez-Vega, Margaret R. Mulholland, Katherine E. Crider, Kimberly E. Powell, P. Dreux Chappell, Alexander Bochdansky

OES Faculty Publications

Margalefidinium polykrikoides is a cosmopolitan dinoflagellate that blooms in coastal waters. Despite genomic evidence that it belongs to Group III and so closely related to isolates from Puerto Rico, Malaysia, North America, and Central America, M. polykrikoides blooms in the Chesapeake Bay at warmer temperatures and lower salinities than in coastal ecosystems occupied by its closest relatives. In this study, the effect of temperature and salinity on the growth rate and total cell yield of an M. polykrikoides VA culture isolate were examined and compared with environmental observations made during M. polykrikoides blooms in the Chesapeake Bay. M. polykrikoides group …


From Wind To Whales: Potential Hydrodynamic Impacts Of Offshore Wind Energy On Nantucket Shoals Regional Ecology, Eileen E. Hofmann, Jeffrey R. Carpenter, Qin J. Chen, Josh T. Kohut, Richard L. Merrick, Erin L. Meyer-Gutbrod, Douglas P. Nowacek, Kaustubha Raghukumar, Nicholas R. Record, Kelly Oskvig Jan 2025

From Wind To Whales: Potential Hydrodynamic Impacts Of Offshore Wind Energy On Nantucket Shoals Regional Ecology, Eileen E. Hofmann, Jeffrey R. Carpenter, Qin J. Chen, Josh T. Kohut, Richard L. Merrick, Erin L. Meyer-Gutbrod, Douglas P. Nowacek, Kaustubha Raghukumar, Nicholas R. Record, Kelly Oskvig

OES Faculty Publications

The National Academy of Sciences, Engineering, and Medicine convened a committee in June 2023 to assess the potential hydrodynamic and ecological impacts from offshore wind energy development in the Nantucket Shoals region, with particular attention to impacts on the critically endangered North Atlantic right whale (Eubalaena glacialis) that forages on zooplankton aggregations in the region. The assessment suggested that the effects of offshore wind energy development will be difficult to distinguish from the effects of natural variability and climate change in this region. The Consensus Study Report recommendations highlight observational and modeling studies that will advance understanding of …


Millennial Pulses Of African Dust And Itcz Shifts In The Eastern Equatorial Pacific, Danielle E. Schimmenti, Franco Marcantonio, M. Roxana Sierra Hernández, Matthew W. Schmidt Jan 2025

Millennial Pulses Of African Dust And Itcz Shifts In The Eastern Equatorial Pacific, Danielle E. Schimmenti, Franco Marcantonio, M. Roxana Sierra Hernández, Matthew W. Schmidt

OES Faculty Publications

We present high-resolution records of detrital Pb and Nd isotopes from marine core site MV1014-02-17JC (00° 10.8297’S, 85° 52.0042’W) in the Eastern Equatorial Pacific (EEP) and use a Bayesian isotope mixing model, MixSIAR, to quantify global dust source contributions since the onset of the last glaciation 30,000 yr ago. We find that in addition to South American dust from the Andean margin, North African dust from the Saharan desert makes up significant proportions of the EEP dust delivered to the site of study. The proportion of North African dust was significantly enhanced during the cold Northern Hemisphere stadials, Heinrich Stadial …


Ensemble Machine Learning Approaches For Bathymetry Estimation In Multi-Spectral Images, Kazi A. Islam, Omar Abdul-Hassan, Hongfang Zhang, Victoria Hill, Blake Schaeffer, Richard Zimmerman, Jiang Li Jan 2025

Ensemble Machine Learning Approaches For Bathymetry Estimation In Multi-Spectral Images, Kazi A. Islam, Omar Abdul-Hassan, Hongfang Zhang, Victoria Hill, Blake Schaeffer, Richard Zimmerman, Jiang Li

OES Faculty Publications

Traditional bathymetry measures require a large number of human hours, and many bathymetry records are obsolete or missing. Automated measures of bathymetry would reduce costs and increase accessibility for research and applications. In this paper, we optimized a recent machine learning model, named CatBoostOpt, to estimate bathymetry based on high-resolution WorldView-2 (WV-2) multi-spectral optical satellite images. CatBoostOpt was demonstrated across the Florida Big Bend coastline, where the model learned correlations between in situ sound Navigation and Ranging (Sonar) bathymetry measurements and the corresponding multi-spectral reflectance values in WV-2 images to map bathymetry. We evaluated three different feature transformations as inputs …


Successful Eastern Oyster (Crassostrea Virginica) Recruitment On Intertidal Artificial Substrates In Virginia, Usa, Rochelle D. Seitz, Kathleen E. Knick, Emily Suchonic, Amanda Pysher Jan 2025

Successful Eastern Oyster (Crassostrea Virginica) Recruitment On Intertidal Artificial Substrates In Virginia, Usa, Rochelle D. Seitz, Kathleen E. Knick, Emily Suchonic, Amanda Pysher

OES Faculty Publications

Declines of eastern oyster (Crassostrea virginica) populations and scarcity of natural oyster shell necessitate quantifying the effectiveness of artificial oyster reef substrates over varying environmental conditions. Oyster castles are often used in intertidal areas with moderate wave energy; however, new concrete, natural-looking substrates, GROW Reef Tiles, are now available. Eastern oyster recruitment and size on oyster castles (OC) and GROW Reef Tiles (GT), with 27% higher surface area on OC, were assessed three times over 25 months in locations with varying salinity. Four sites in the Chesapeake Bay region were examined: Cherrystone Inlet, Mockhorn Bay, Elizabeth River, and …


Core-Top Constraints On The Ecology And Paleothermometry Of Planktic Foraminifera In The Indian Ocean, Ryan H. Glaubke, Elisabeth L. Sikes, Natalie E. Umling, Katherine A. Allen, Matthew W. Schmidt Jan 2025

Core-Top Constraints On The Ecology And Paleothermometry Of Planktic Foraminifera In The Indian Ocean, Ryan H. Glaubke, Elisabeth L. Sikes, Natalie E. Umling, Katherine A. Allen, Matthew W. Schmidt

OES Faculty Publications

The magnesium-to‑calcium ratio (Mg/Ca) of fossil foraminifera is a widely used geochemical proxy for reconstructing past ocean temperatures. Culturing experiments have shown that, for some species, nonthermal influences like salinity and carbonate chemistry play a non-trivial role in the incorporation of Mg into foraminiferal calcite. Inclusion of these variables into Mg/Ca calibrations have provided a better fit to core top and sediment trap data in some recent studies, but the widespread covariation of potential control variables in the open ocean and the lack of multivariate calibrations for some species warrants additional work. Here, we assess Mg/Ca calibrations for four common …


High Antarctic Coastal Productivity In Polynyas Revealed By Considering Remote Sensing Ice-Adjacency Effects, Hilde Oliver, Jessica S. Turner, Alexandre Castagna, Henry Houskeeper, Heidi Dierssen Jan 2025

High Antarctic Coastal Productivity In Polynyas Revealed By Considering Remote Sensing Ice-Adjacency Effects, Hilde Oliver, Jessica S. Turner, Alexandre Castagna, Henry Houskeeper, Heidi Dierssen

OES Faculty Publications

Ocean color-based estimates of Antarctic net primary productivity (NPP) have indicated low nearshore productivity in ice-adjacent waters, contrasting with coupled physical–biogeochemical models. To understand this discrepancy, we assessed satellite records of polynya NPP by comparing field data with two satellite imagery datasets derived using different processing schemes. Our results indicate historical underestimation of chlorophyll a for imagery obtained using default atmospheric correction processing within approximately 100 km of ice-covered coastlines due to adjacency effects. Using radiative transfer modeling, we find that biases in ocean color polynya observations due to adjacency effects correspond to the high albedo of ice and snow. …


Elucidating The Role Of Marine Benthic Carbon In A Changing World, Cristina Schultz, Jessica Y. Luo, Damian C. Brady, Robinson W. Fulwiler, Matthew H. Long, Colleen M. Petrik, Jeremy M. Testa, Heather M. Benway, David Burdige, Marta M. Cecchetto, Isa Elegbede, Natalya Evans, Alexandra Frenzel, Kayla Gillen, Lisa C. Herbert, Heidi K. Hirsh, Gennadi Lessin, Lisa Levin, Kanchan Maiti, Sairah Malkin, Sarah L. Mincks, Stanley Nmor, Anh Pham, James Pinckney, Christophe Rabouille, Shaily Rahman, Subhadeep Rakshit, Nicholas E. Ray, Dalton K. Sasaki, Samantha A. Siedlecki, Christopher Somes, Aron Stubbins, Olivier Sulpis, Cleuza Trevisan, Yiyang Xu, Hang Yin Jan 2025

Elucidating The Role Of Marine Benthic Carbon In A Changing World, Cristina Schultz, Jessica Y. Luo, Damian C. Brady, Robinson W. Fulwiler, Matthew H. Long, Colleen M. Petrik, Jeremy M. Testa, Heather M. Benway, David Burdige, Marta M. Cecchetto, Isa Elegbede, Natalya Evans, Alexandra Frenzel, Kayla Gillen, Lisa C. Herbert, Heidi K. Hirsh, Gennadi Lessin, Lisa Levin, Kanchan Maiti, Sairah Malkin, Sarah L. Mincks, Stanley Nmor, Anh Pham, James Pinckney, Christophe Rabouille, Shaily Rahman, Subhadeep Rakshit, Nicholas E. Ray, Dalton K. Sasaki, Samantha A. Siedlecki, Christopher Somes, Aron Stubbins, Olivier Sulpis, Cleuza Trevisan, Yiyang Xu, Hang Yin

OES Faculty Publications

The ocean plays a major role in controlling atmospheric carbon at decadal to millennial timescales, with benthic carbon representing the only geologic-scale storage of oceanic carbon. Despite its importance, detailed benthic ocean observations are limited and representation of the benthic carbon cycle in ocean and Earth system models (ESMs) is mostly empirical with little prognostic capacity, which hinders our ability to properly understand the long-term evolution of the carbon cycle and climate change-related feedbacks. The Benthic Ecosystem and Carbon Synthesis (BECS) working group, with the support of the US Ocean Carbon & Biogeochemistry Program (OCB), identified key challenges limiting our …


Yucatan Hurricane Activity Highlights Common Era Tropical Cyclone Dipole, Richard M. Sullivan, Peter J. Van Hengstum, Elizabeth J. Wallace, Sloan Coats, Jeffrey P. Donnelly, Robert Korty, Shawna N. Little, Martin G. Maas Vargas, Luis Mejia-Ortiz, Eduard G. Reinhardt, Courtney Schumacher, Anne E. Tamalavage, Tyler S. Winkler Jan 2025

Yucatan Hurricane Activity Highlights Common Era Tropical Cyclone Dipole, Richard M. Sullivan, Peter J. Van Hengstum, Elizabeth J. Wallace, Sloan Coats, Jeffrey P. Donnelly, Robert Korty, Shawna N. Little, Martin G. Maas Vargas, Luis Mejia-Ortiz, Eduard G. Reinhardt, Courtney Schumacher, Anne E. Tamalavage, Tyler S. Winkler

OES Faculty Publications

Tropical cyclone (TC) impacts along the western Atlantic and Caribbean margin are not spatially uniform. Proxy based reconstructions of Common Era TC activity highlight this non-uniform distribution at centennial-millennial timescales. However, the sparse geographic scope of these reconstructions impedes our assessment of TC landfalls across broader spatial domains. This work presents a compilation of new and existing TC reconstructions from the Yucatan Peninsula for comparison with a contemporaneous compilation from New England, showing that these regions occupy distal nodes of a low-frequency TC dipole. Increased Yucatan (New England) storminess is closely linked to intervals of Northern Hemisphere warming (cooling) and …


Unveiling Hidden Mercury And Methylmercury Sources: The Role Of Submarine Groundwater Discharge In Coastal Lagoons, Céline Lavergne, Júlia Rodriguez-Puig, Clara Ruiz-González, Maria Montero-Curiel, Gemma Casas, Daniel Romano-Gude, Irene Alorda-Montiel, Júlia Dordal-Soriano, Aaron Alorda-Kleinglass, Marc Diego-Feliu, Javier Gilabert, Alex Campillo-De La Maza, Cristina Romera-Castillo, Natalia Torres-Rodriguez, Lars-Eric Heimbürger-Boavida, Jordi Garcia-Orellana, Valenti Rodellas, Andrea G. Bravo Jan 2025

Unveiling Hidden Mercury And Methylmercury Sources: The Role Of Submarine Groundwater Discharge In Coastal Lagoons, Céline Lavergne, Júlia Rodriguez-Puig, Clara Ruiz-González, Maria Montero-Curiel, Gemma Casas, Daniel Romano-Gude, Irene Alorda-Montiel, Júlia Dordal-Soriano, Aaron Alorda-Kleinglass, Marc Diego-Feliu, Javier Gilabert, Alex Campillo-De La Maza, Cristina Romera-Castillo, Natalia Torres-Rodriguez, Lars-Eric Heimbürger-Boavida, Jordi Garcia-Orellana, Valenti Rodellas, Andrea G. Bravo

OES Faculty Publications

Mercury loads from Submarine Groundwater Discharge (SGD) may represent an overlooked source of methylmercury (MeHg) to the ocean, affecting human and ecosystem health. The SGD process involves the flow of fresh, saline, or mixed groundwater from coastal aquifers into the oceans classified in different components. Existing studies rarely report the fluxes supplied by the different SGD components; therefore, the relevance of SGD as a source of mercury remains unclear. We aimed to quantify SGD-driven mercury/methylmercury fluxes to the coast, focusing on the largest coastal lagoon in the western Mediterranean. We measured total dissolved mercury and MeHg in surficial and porewaters …


Dynamics Of Water Mass Exchange Across The Central Ross Sea Slope, Yuanjie Chen, Zhaoru Zhang, Pasquale Castagno, Xianxian Han, Michael S. Dinniman, Zhiqiang Liu, Chuning Wang Jan 2025

Dynamics Of Water Mass Exchange Across The Central Ross Sea Slope, Yuanjie Chen, Zhaoru Zhang, Pasquale Castagno, Xianxian Han, Michael S. Dinniman, Zhiqiang Liu, Chuning Wang

OES Faculty Publications

The central Ross Sea slope (CRSS) is a critical region for water mass exchange, significantly influencing the physical and biological processes of the Ross Sea shelf and the global overturning circulation. This study utilizes a high-resolution ocean-ice shelf-sea ice coupled model to investigate the mechanisms driving this exchange, involving the onshore transport of circumpolar deep water (CDW) and the offshore transport of dense shelf water (DSW). Combining numerical simulations and mooring observations, this work reveals high-frequency oscillations with a periodicity of ∼32 hr in CDW transport induced by Topographic Rossby Waves and DSW transport induced by cyclonic eddies. These findings …


Impact Of Submarine Groundwater Discharge On Microbial Communities In A Highly Anthropized Coastal Lagoon (Mar Menor, Se Spain), Daniel Romano-Gude, Júlia Dordal-Soriano, Júlia Rodriguez-Puig, Andrea G. Bravo, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Marc Diego-Feliu, Cristina Romera-Castillo, Rebeca Mallenco-Fornies, Javier Gilabert, Jordi Garcia-Orellana, Valentí Rodellas, Clara Ruiz-González Jan 2025

Impact Of Submarine Groundwater Discharge On Microbial Communities In A Highly Anthropized Coastal Lagoon (Mar Menor, Se Spain), Daniel Romano-Gude, Júlia Dordal-Soriano, Júlia Rodriguez-Puig, Andrea G. Bravo, Irene Alorda-Montiel, Aaron Alorda-Kleinglass, Marc Diego-Feliu, Cristina Romera-Castillo, Rebeca Mallenco-Fornies, Javier Gilabert, Jordi Garcia-Orellana, Valentí Rodellas, Clara Ruiz-González

OES Faculty Publications

Submarine groundwater discharge (SGD) supplies large quantities of nutrients and other terrestrial elements to coastal ecosystems, impacting marine biota and ecosystem functioning. Despite the relevance of prokaryotes for marine biogeochemistry, little is known about their responses to groundwater inputs. Here we explored the impact of SGD on the spatiotemporal patterns of prokaryotic communities from the Mar Menor (Murcia, Spain), a highly anthropized hypersaline coastal lagoon that receives large amounts of nutrient-polluted SGD. Using 16S rRNA amplicon sequencing, activity assays, and flow cytometry, we investigated the dynamics of prokaryotic communities across the lagoon and its connected environments (freshwater streams, groundwater, soils, …


Common Era Time-Transgressive Forcing Of Caribbean Water Balance, Peter J. Van Hengstum, Shawna N. Little, Richard M. Sullivan, Jeffrey P. Donnelly, Tyler S. Winkler, Anne E. Tamalavage, Patricia A. Beddows, Patricia L. Fall, Jiabi Du, Kaustubh Thirumalai, Nancy A. Albury, Sloan Coats Jan 2025

Common Era Time-Transgressive Forcing Of Caribbean Water Balance, Peter J. Van Hengstum, Shawna N. Little, Richard M. Sullivan, Jeffrey P. Donnelly, Tyler S. Winkler, Anne E. Tamalavage, Patricia A. Beddows, Patricia L. Fall, Jiabi Du, Kaustubh Thirumalai, Nancy A. Albury, Sloan Coats

OES Faculty Publications

Tropical North Atlantic sea surface temperatures and low-latitude rainfall covary, but prehistoric subtropical rainfall records are often misaligned. Here, a submarine groundwater discharge record from the northern Bahamas archives regional water balance in the northeastern Atlantic Warm Pool. We compare the reconstruction to the tropical North Atlantic seasonal temperature gradient, which can help inform how northeastern Caribbean rainy seasons are influenced by the Atlantic Warm Pool. A positive water balance in the northern Bahamas aligned with a ~0.9 °C seasonal temperature gradient from 0 to 950 CE, with both covarying on multi-decadal timescales. Aridity began at ~950 CE when a …


Multi-Centennial Spatial Coherency Among Atlantic Tropical Cyclones From Simulated And Reconstructed Storm Records, Richard M. Sullivan, Elizabeth Wallace, Sylvia Dee, Gabiel A. Vecchi, Wenchang Yang, Kerry Emanuel Jan 2025

Multi-Centennial Spatial Coherency Among Atlantic Tropical Cyclones From Simulated And Reconstructed Storm Records, Richard M. Sullivan, Elizabeth Wallace, Sylvia Dee, Gabiel A. Vecchi, Wenchang Yang, Kerry Emanuel

OES Faculty Publications

Proxy-based reconstructions of long-term Atlantic tropical cyclone (TC) variability reveal low-frequency oscillations in regional TC landfalls over the Common Era. However, the limited spatial coverage and increased uncertainty of the proxy records complicates assessments of this feature. Here we present a new multi-ensemble set of synthetic TCs downscaled from the Last Millennium Reanalysis project, which is based on sea surface temperatures that more accurately reflect past conditions. Throughout ensemble members, there are coherent multi-centennial shifts in landfalls with persistent intervals of increased (decreased) occurrence along the eastern US concurrent with inverse activity in the southwest Caribbean and Gulf of Mexico, …


Organic Carbon Decay Mediated By A Mesopelagic Microbial Community: The Relevance Of Carbon Pools And Broad Biochemical Composition, Noah J. Craft, Alexander B. Bochdansky Jan 2025

Organic Carbon Decay Mediated By A Mesopelagic Microbial Community: The Relevance Of Carbon Pools And Broad Biochemical Composition, Noah J. Craft, Alexander B. Bochdansky

OES Faculty Publications

The mesopelagic zone is a site of strong microbially driven particle attenuation with depth and thus plays a crucial role in controlling the transfer efficiency of the ocean's biological pump. However, little quantitative information exists on the dependency of decay processes on the source material. Here we followed the decay of ¹⁴C-labeled dead particulate organic carbon (POC) and dissolved organic carbon (DOC) from three different phytoplankton species, and two incubations of live diatoms, in mesopelagic water over 3 months. Commonly used first-order kinetics failed to adequately describe the decay of organic material as rate constants varied from day to day. …


The Relative Contribution Of Deep And Shallow Benthic Sources To Iron Supply In The Ross Sea, With Specific Emphasis On The Ross Bank, Blair J.W. Greenan, Michael S. Dinniman, Dennis J. Mcgillicuddy Jr., Peter N. Sedwick, Stefanie L. Mack, Walker O. Smith Jr. Jan 2025

The Relative Contribution Of Deep And Shallow Benthic Sources To Iron Supply In The Ross Sea, With Specific Emphasis On The Ross Bank, Blair J.W. Greenan, Michael S. Dinniman, Dennis J. Mcgillicuddy Jr., Peter N. Sedwick, Stefanie L. Mack, Walker O. Smith Jr.

OES Faculty Publications

Summer primary productivity in the Ross Sea is limited by the availability of dissolved iron (DFe) in the euphotic zone. Previous studies have suggested that benthic sources dominate the supply of DFe to the upper water column in the southern Ross Sea polynya. The purpose of this study is to investigate whether these benthic sources are derived from shallow banks or deeper areas of the continental shelf. Our study combines analysis of in situ observations near Ross Bank with a physical ocean model simulation in an overlapping summertime period to investigate the vertical supply of DFe. Two passive tracer dyes …


Pygoscelis Penguins Prefer Different Oceanographic And Terrestrial Habitats During The Austral Summer, Katherine L. Gallagher, Rachel Herman, Katherine Walton, Michael S. Dinniman, Heather J. Lynch Jan 2025

Pygoscelis Penguins Prefer Different Oceanographic And Terrestrial Habitats During The Austral Summer, Katherine L. Gallagher, Rachel Herman, Katherine Walton, Michael S. Dinniman, Heather J. Lynch

OES Faculty Publications

Pygoscelis penguins interact with both terrestrial and marine environments, especially during the austral summer when they raise their chicks. Accessible ice-free ground spaces serve as locations for penguins to build colonies and successfully raise chicks while the surrounding marine environment serves as the foraging grounds for adult birds. Penguins must be able to navigate through the waters around their colonies to forage for Antarctic krill (Euphausia superba), their primary prey during the austral summer. Krill, whose distributions are driven partially by the surrounding physics and partially by their behaviors, must also be plentiful in the waters near the …


Sandy Subterranean Estuaries Minimize Groundwater Nitrogen Pollution Impacts On Coastal Waters, Xiaogang Chen, Isaac R. Santos, Jinzhou Du, Bochao Xu, Joseph J. Tamborski, Ding He, Neven Cukrov, Christian J. Sanders, Jianan Liu, Peiyuan Zhu, Yan Zhang, Ling Li Jan 2025

Sandy Subterranean Estuaries Minimize Groundwater Nitrogen Pollution Impacts On Coastal Waters, Xiaogang Chen, Isaac R. Santos, Jinzhou Du, Bochao Xu, Joseph J. Tamborski, Ding He, Neven Cukrov, Christian J. Sanders, Jianan Liu, Peiyuan Zhu, Yan Zhang, Ling Li

OES Faculty Publications

Widespread anthropogenic activities pollute groundwater that eventually seeps out to the coastal ocean. Here, we resolve nutrient transformations and fluxes in 11 sandy subterranean estuaries (STEs) with contrasting nutrient sources and development trajectories. Coastal groundwater nitrogen pollution stems from sewage discharge and land use change. Anthropogenically derived groundwater nutrient fluxes with high N/P ratios (∼170) accounted for 22%–61% of riverine inputs into China's coastal waters, providing an additional source of nutrients that can fuel coastal eutrophication and algal blooms. Sandy STEs remarkably attenuated ∼84% of nitrogen pollution, minimizing the impact of submarine groundwater discharge (SGD) on coastal water quality. Hence, …


The Δ¹³C Signature Of Dissolved Organic And Inorganic Carbon Reveals Complex Carbon Transformations Within A Salt Marsh, Meagan J. Eagle, Kevin D. Kroeger, John W. Pohlman, Joseph J. Tamborski, Zhaohui Aleck Wang, T. W. Brooks, Jennifer O. Keefe Suttles, Adrian Mann Jan 2025

The Δ¹³C Signature Of Dissolved Organic And Inorganic Carbon Reveals Complex Carbon Transformations Within A Salt Marsh, Meagan J. Eagle, Kevin D. Kroeger, John W. Pohlman, Joseph J. Tamborski, Zhaohui Aleck Wang, T. W. Brooks, Jennifer O. Keefe Suttles, Adrian Mann

OES Faculty Publications

Coastal wetlands have high rates of atmospheric CO₂ uptake, which is subsequently respired back to the atmosphere, stored as organic matter within flooded, anoxic soils, or exported to the coastal ocean. Transformation of fixed carbon occurs through a variety of subsurface aerobic and anaerobic microbial processes, and results in a large inventory of dissolved carbon. Carbon source and the roles of aerobic respiration, sulfate reduction, and methane cycling were evaluated within salt marsh peat and the underlying sandy subterranean estuary. There is a large increase in dissolved inorganic carbon (DIC, 7,350 ± 3,900 μmol L-¹), dissolved organic carbon …


Dust Deposition To The Sargasso Sea: A Comparison Of Estimates Using Aluminum In The Surface Ocean Versus Aerosols And Rainwater, T. E. Williams, P. N. Sedwick, B. M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, J. A. Resing, L. E. Sofen, A. Tagliabue, B. S. Twining Jan 2025

Dust Deposition To The Sargasso Sea: A Comparison Of Estimates Using Aluminum In The Surface Ocean Versus Aerosols And Rainwater, T. E. Williams, P. N. Sedwick, B. M. Sohst, K. N. Buck, S. Caprara, R. J. Johnson, D. C. Ohnemus, J. A. Resing, L. E. Sofen, A. Tagliabue, B. S. Twining

OES Faculty Publications

As a major component of mineral aerosol that partially dissolves in seawater, aluminum (Al) has been used to estimate time-averaged dust fluxes to the ocean, based on dissolved aluminum (DAl) concentrations and an assumed replacement time of DAl (tau DAl) in the surface mixed layer, along with the fractional solubility (Als) and mass abundance of Al in dust. We apply this method in the Bermuda region using seasonal water-column DAl concentrations, and compare our results with fluxes estimated from Al measured in Bermuda aerosols and rain. Inventories of DAl over the maximum mixed-layer depth of 200 m and empirically derived …


Characterization Of Microbial Biofilms On Marine Plastics: Community Development And Density Implications For Vertical Transport Dynamics, Gregory M. Joern, Rut Pedrosa-Pàmies, Xiangtao Jiang, Zhanfei Liu, Alexander B. Bochdansky Jan 2025

Characterization Of Microbial Biofilms On Marine Plastics: Community Development And Density Implications For Vertical Transport Dynamics, Gregory M. Joern, Rut Pedrosa-Pàmies, Xiangtao Jiang, Zhanfei Liu, Alexander B. Bochdansky

OES Faculty Publications

Marine plastic pollution poses a significant and escalating threat to ocean ecosystems, with microbial colonization on plastics playing a critical role in determining their environmental fate. Despite the recognized importance of microbial biofilms, their composition, dynamics, and functional contributions on buoyant plastics remain poorly understood. In this study, we leveraged a novel integrative approach by simultaneously employing 16S, 18S, and ITS sequencing alongside microscopy, lipidomics, pigment analysis, adenosine triphosphate and biogenic silica quantification. This comprehensive methodology allowed for a thorough characterization of microbial growth and community dynamics on plastic debris in a mid-latitude, tidal sub-estuary. Our analyses consistently identified diatoms, …


Evidence Of Mineral Alteration In A Salt Marsh Subterranean Estuary: Implications For Carbon And Trace Element Cycling, J. J. Tamborski, M. J. Eagle, M. T. Thorpe, M. A. Charette, B. L. Kurylyk, S. Rahman, K. D. Kroeger, J. O'Keefe Suttles, A. G. Mann, T. W. Brooks, Z. A. Wang Jan 2025

Evidence Of Mineral Alteration In A Salt Marsh Subterranean Estuary: Implications For Carbon And Trace Element Cycling, J. J. Tamborski, M. J. Eagle, M. T. Thorpe, M. A. Charette, B. L. Kurylyk, S. Rahman, K. D. Kroeger, J. O'Keefe Suttles, A. G. Mann, T. W. Brooks, Z. A. Wang

OES Faculty Publications

Subterranean estuaries (STE) in salt marshes are biogeochemically active zones where interactions between terrestrial groundwater and seawater drive complex cycling of carbon and trace elements, influenced by mineral dissolution. These systems, characterized by fine-grained organic-rich peat overlying permeable coastal aquifers, play a crucial role as a blue carbon sink, yet their geochemical dynamics remain poorly understood. We investigated dissolved trace elements, carbon, silica, and radium isotopes in a salt marsh STE (Sage Lot Pond, Waquoit Bay, MA) over seasonal and annual cycles. Our results reveal that groundwater and estuarine water circulation through marsh peat and aquifer sediments leads to enrichments …


Collision-Induced Absorption Spectra Of N₂ And Ch₄, Ryan M. Johnson, Peter F. Bernath, Brant Billinghurst, Jianbao Zhao Jan 2025

Collision-Induced Absorption Spectra Of N₂ And Ch₄, Ryan M. Johnson, Peter F. Bernath, Brant Billinghurst, Jianbao Zhao

Chemistry & Biochemistry Faculty Publications

Collision-induced spectra are essential for radiative transfer modeling of Titan's atmosphere. We present experimental spectra of nitrogen–methane mixtures with an accompanying fit of N₂-CH₄ collision-induced absorption in the 30–400 cm⁻¹ region at about 130 K. We found a peak absorption of 2.30 × 10⁻⁵ cm⁻¹ amagat⁻² at 75 cm⁻¹ and a secondary peak of 1.35 × 10⁻⁵ c⁻¹ amagat⁻² at 206.5 cm⁻¹, which agrees with previous studies. Our work does not support the suggestion that N₂-CH₄ CIA in the far-infrared should be increased by about 50%, as suggested by spectroscopic modeling of Titan using data from A. Borysow & C. …


An Ecofeminist Approach To Climate Risks, Angela Hefti Jan 2025

An Ecofeminist Approach To Climate Risks, Angela Hefti

Michigan Journal of International Law

Climate change poses significant risks to the human right to life. However, international adjudicators have either neglected to examine right to life claims in the context of climate risks or dismissed them as prospective and speculative. International human rights bodies have long applied the standard of imminence to determine whether a threat to the right to life exists and the extent to which it constitutes a violation. In climate change cases, this standard has hardened, requiring a tight temporal connection between climate risks and a violation of the right to life. This article argues that failing to recognize the impact …