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Articles 211 - 240 of 13989

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Variation In Food Web Reliance On Green And Brown Energy Pathways Across Ecosystem Gradients, James W. Sturges, W. Ryan James, Ryan J. Rezek, Rolando O. Santos, Mack White, Gina A. Badlowski, Shakira Trabelsi, Jordan Massie, Justin S. Lesser, Joel C. Trexler, James Nelson, Jennifer S. Rehage Feb 2026

Variation In Food Web Reliance On Green And Brown Energy Pathways Across Ecosystem Gradients, James W. Sturges, W. Ryan James, Ryan J. Rezek, Rolando O. Santos, Mack White, Gina A. Badlowski, Shakira Trabelsi, Jordan Massie, Justin S. Lesser, Joel C. Trexler, James Nelson, Jennifer S. Rehage

Marine Science

Aquatic food webs typically include highly coupled fast, ‘green’ energy pathways driven by algae or phytoplankton and slower, ‘brown’ energy channels driven by detritus and terrestrial plants. Quantifying how much energy biological communities obtain from each of these pathways is essential, particularly across multiple interconnected food webs over large areas, because energy dynamics are known to influence ecosystem structure and function. Despite their importance, few studies track variance in energy channel contributions to food webs across interconnected habitats during distinct hydrologic seasons. In this study, we used tri-isotope Bayesian mixing models to quantify seasonal contributions of energy pathways to consumers …


2026 February - Tennessee Climate Snapshot, Tennessee Climate Office, East Tennessee State University Feb 2026

2026 February - Tennessee Climate Snapshot, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.


Microplastics In St. John, United States Virgin Islands Sediments: Methodological Approaches And Variability Of Microplastics Concentrations And Accumulation Rates, Henry B. Arbaugh, Sarah C. Gray, Dimitri Deheyn Jan 2026

Microplastics In St. John, United States Virgin Islands Sediments: Methodological Approaches And Variability Of Microplastics Concentrations And Accumulation Rates, Henry B. Arbaugh, Sarah C. Gray, Dimitri Deheyn

Theses

Sediment samples were collected from a near shore and reef site in Coral Bay, St. John, United States Virgin Islands (USVI) from 2007-2016, using tube sediment traps. These samples provide an opportunity to study microplastics (MPs) in an area where no previous MP studies have been performed. Most sedimentary MP studies utilize benthic samples which can only measure MP concentrations (#MP/g or #MP/mL sediment), while sediment traps can provide MP accumulation rates (#MP/cm2/day) as a function of time. However, the methods used for extracting MPs from benthic samples have not been tested using sediment trap samples whose characteristics, …


A Systematic Literature Review On The Influence Of The El Niño Southern Oscillation On Rainfall Variability In Central Java, Indonesia, Sri Endah Ardhi Ningrum Abdullah, Trinah Wati, Wahyu Hardyanto Jan 2026

A Systematic Literature Review On The Influence Of The El Niño Southern Oscillation On Rainfall Variability In Central Java, Indonesia, Sri Endah Ardhi Ningrum Abdullah, Trinah Wati, Wahyu Hardyanto

Jurnal Pendidikan Geografi: Kajian, Teori, dan Praktek dalam Bidang Pendidikan dan Ilmu Geografi

The El Niño-Southern Oscillation (ENSO) phenomenon greatly influences rainfall variability in tropical regions, including Central Java, Indonesia. This study employs a Systematic Literature Review (SLR) approach in accordance with the PRISMA guidelines. This study examines 50 articles from 2010 to 2025, as well as conducting a bibliometric analysis using VOSviewer, to identify trends and the evolution of themes. The results of the study indicate that El Niño generally reduces rainfall and increases the risk of drought, while La Niña tends to increase rainfall, potentially causing flooding. The impacts of ENSO extend to agriculture, food security, and water management, and are …


A High-Resolution Daily Precipitation Fusion Framework Integrating Radar, Satellite, And Nwp Data Using Machine Learning Over South Korea, Hyoju Park, Hiroyuki Miyazaki, Menas Kafatos, Seung Hee Kim, Yangwon Lee Jan 2026

A High-Resolution Daily Precipitation Fusion Framework Integrating Radar, Satellite, And Nwp Data Using Machine Learning Over South Korea, Hyoju Park, Hiroyuki Miyazaki, Menas Kafatos, Seung Hee Kim, Yangwon Lee

Institute for ECHO Articles and Research

Accurate precipitation mapping is essential for effective disaster management; however, individual radar, satellite, and numerical weather prediction products often struggle in the topographically complex terrain of South Korea. This study proposes a high-resolution (~500 m) daily precipitation fusion framework that integrates Korea Meteorological Administration (KMA) radar, Global Precipitation Measurement (GPM) Integrated Multi-Satellite Retrievals for GPM (IMERG), and Local Data Assimilation and Prediction System (LDAPS) data. The framework employs a Random Forest model augmented with a monthly Empirical Cumulative Distribution Function (ECDF) correction. Auxiliary predictors are incorporated to enhance physical interpretability and stability, including terrain attributes to represent orographic effects, land-cover …


2026 January 29 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January 29 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


Observation-Based Reconstruction Of High-Resolution Daily Temperature Field Using Lapse-Rate-Constrained Kriging In Complex Terrain: A Nationwide Dataset For South Korea, Youjeong Youn, Menas Kafatos, Seung Hee Kim, Yangwon Lee Jan 2026

Observation-Based Reconstruction Of High-Resolution Daily Temperature Field Using Lapse-Rate-Constrained Kriging In Complex Terrain: A Nationwide Dataset For South Korea, Youjeong Youn, Menas Kafatos, Seung Hee Kim, Yangwon Lee

Institute for ECHO Articles and Research

High-resolution air-temperature fields are essential for climate, hydrologic, and ecological applications in complex terrain, yet operational products often lack the spatial detail to resolve topographic effects. We develop an observation-driven reconstruction of daily air temperature fields for South Korea (2024) using ordinary kriging with lapse-rate correction (OKLR), integrating a dense network of over 500 stations from the Automatic Mountain Meteorology Observation System (AMOS) and the Automated Surface Observing System (ASOS). The OKLR framework systematically removes elevation-driven trends using a physically based fixed lapse rate (–6.5 °C km−1), performs kriging on detrended residuals, and reapplies Digital Elevation Model (DEM)-based corrections to …


Data And Code For "Stratocumulus Drizzle Readily, Cumulus Drizzle Selectively: Evidence From Four Oceanic Regions", Katia Lamer Jan 2026

Data And Code For "Stratocumulus Drizzle Readily, Cumulus Drizzle Selectively: Evidence From Four Oceanic Regions", Katia Lamer

SoMAS Research Data

Data and Code for "Stratocumulus drizzle readily, cumulus drizzle selectively: evidence from four oceanic regions"


2026 January 22 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January 22 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


A Robust Deep Learning Ensemble Framework For Waterbody Detection Using High-Resolution X-Band Sar Under Data-Constrained Conditions, Soyeon Choi, Seung Hee Kim, Son V. Nghiem, Menas Kafatos, Minha Choi, Jinsoo Kim, Yangwon Lee Jan 2026

A Robust Deep Learning Ensemble Framework For Waterbody Detection Using High-Resolution X-Band Sar Under Data-Constrained Conditions, Soyeon Choi, Seung Hee Kim, Son V. Nghiem, Menas Kafatos, Minha Choi, Jinsoo Kim, Yangwon Lee

Institute for ECHO Articles and Research

Accurate delineation of inland waterbodies is critical for applications such as hydrological monitoring, disaster response preparedness and response, and environmental management. While optical satellite imagery is hindered by cloud cover or low-light conditions, Synthetic Aperture Radar (SAR) provides consistent surface observations regardless of weather or illumination. This study introduces a deep learning-based ensemble framework for precise inland waterbody detection using high-resolution X-band Capella SAR imagery. To improve the discrimination of water from spectrally similar non-water surfaces (e.g., roads and urban structures), an 8-channel input configuration was developed by incorporating auxiliary geospatial features such as height above nearest drainage (HAND), slope, …


2026 January 15 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January 15 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


A Comparison Of Modeled Daytime E Regions From E-Probed And Pyiri With Ionosonde Observations, Daniel J. Emmons, Cornelius C. J. H. Salinas, Dong L. Wu, Nimalan Swarnalingam, Eugene V. Dao, Jorge L. Chau, Yosuke Yamazaki, Kyle E. Fitch, Victoriya V. Forsythe Jan 2026

A Comparison Of Modeled Daytime E Regions From E-Probed And Pyiri With Ionosonde Observations, Daniel J. Emmons, Cornelius C. J. H. Salinas, Dong L. Wu, Nimalan Swarnalingam, Eugene V. Dao, Jorge L. Chau, Yosuke Yamazaki, Kyle E. Fitch, Victoriya V. Forsythe

Faculty Publications

While the F region is the primary focus of many ionospheric models because it contains the peak electron density, the E region is an important region for ionospheric conductivities and high-frequency radio propagation. This study analyzes modeled E regions from the newly developed PyIRI and E-PROBED models. A long-term comparison of E region predictions from E-PROBED and PyIRI with ionosonde observations is performed for three sites spanning low- (Fortaleza, Brazil), mid- (El Arenosillo, Spain), and high-latitudes (Gakona, Alaska). Modeled foE and hmE trends are compared against a combination of manually-scaled and automatically-scaled ionograms using ARTIST-5 for the period 2009–2024 for …


2026 January 8 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January 8 - Tennessee Weekly Drought Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Weekly Drought Summaries

No abstract provided.


Metacommunity Coupled Epidemiological And Biophysical Modeling Of An Emergent Coral Disease, Benjamin Holmes Farmer Jan 2026

Metacommunity Coupled Epidemiological And Biophysical Modeling Of An Emergent Coral Disease, Benjamin Holmes Farmer

LSU Doctoral Dissertations

Emerging infectious diseases pose imminent risk to the marine realm and coral reefs in particular. Since its emergence in 2014, stony coral tissue loss disease (SCTLD) has dramatically reduced living coral cover in Florida and charted a similar course in the Caribbean. SCTLD is by far the most severe coral disease in history and has driven highly susceptible species to local extinction, yet the mechanisms driving the regional epizootic are not well understood. Here, we developed reef-scale parameterizations of disease spread using model sites in the lower Florida Keys, developed extensive metacommunity habitat maps for the US Caribbean, and then …


Synthesis Study Of Evapotranspiration Evolution In The Mekong Delta Induced By Land Use And Land Cover Changes In The Decades Of 1990–2020, Emiliana Valentini, Serena Sapio, Son V. Nghiem, Seung Hee Kim, Sara Liburdi, Andrea Taramelli Jan 2026

Synthesis Study Of Evapotranspiration Evolution In The Mekong Delta Induced By Land Use And Land Cover Changes In The Decades Of 1990–2020, Emiliana Valentini, Serena Sapio, Son V. Nghiem, Seung Hee Kim, Sara Liburdi, Andrea Taramelli

Institute for ECHO Articles and Research

Evapotranspiration (ET) plays a key role in the water cycle and balance, and its estimation is of paramount importance in hydrological studies. This variable is also strongly influenced by the land use and land cover (LULC). This study use a synthesis approach to analyse the relationship between ET variation and LULC transformation in the period 1990–2020. The study area represents a major agricultural region in the Mekong Delta of Vietnam between the Mekong and Bassac rivers. The multivariate dataset was ingested into the hydrological model Soil and Water Assessment Tool to examine the multidecadal ET evolution across the study region. …


2026 January - Tennessee Climate Snapshot, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January - Tennessee Climate Snapshot, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.


2026 January - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University Jan 2026

2026 January - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

Hi All,

The main weather and climate story of January 2026 was the major winter storm that impacted the state from Saturday, January 24 through Monday, January 26 with rain, freezing rain, sleet, and snow, followed by extremely cold conditions. Winter storm warnings and winter weather advisories were in place across the state on Friday, January 23, as snow and sleet spread into Tennessee from the west in the overnight hours of Friday into Saturday. Most areas of the state saw an initial round of snow and sleet, before a layer of warm air aloft caused most locations to see …


Captive Model Test For Hydrodynamic Derivatives Of Ship Maneuvering In Regular Head Waves, Pin-Yuan Huang, Zih-Yao Lin, Tsung-Yueh Lin, Fu-En Lee, Yan-Wei Lai Jan 2026

Captive Model Test For Hydrodynamic Derivatives Of Ship Maneuvering In Regular Head Waves, Pin-Yuan Huang, Zih-Yao Lin, Tsung-Yueh Lin, Fu-En Lee, Yan-Wei Lai

Journal of Marine Science and Technology–Taiwan

The motion of ship in wave can be discussed in seakeeping and maneuvering. In model tests, the former is found by the motion response of waves while the latter requires captive model test to acquire hydrodynamic derivatives. The hydrodynamic derivatives in waves are discovered to be different from those in calm water. To understand better the behavior of maneuverability in waves, maneuvering tests in a wide range of waves are performed in this study. This study presents an experimental investigation into the maneuvering behavior of a container ship in regular waves, covering a wide range of wavelengths from half to …


A Comprehensive Statistical And Regional Analysis Of Lng-Powered Marine Vessels On Ghg Mitigation Strategies Considering Existing Bunkering Stations And Gwp Values, Canberk Hazar, Onur Yuksel, Murat Bayraktar Jan 2026

A Comprehensive Statistical And Regional Analysis Of Lng-Powered Marine Vessels On Ghg Mitigation Strategies Considering Existing Bunkering Stations And Gwp Values, Canberk Hazar, Onur Yuksel, Murat Bayraktar

Journal of Marine Science and Technology–Taiwan

This study aims to quantify and analyse emissions from marine vessels that can operate on liquefied natural gas (LNG) but continue to use conventional fuels, largely due to the limited availability of LNG bunkering stations (BSs) over long distances. Four regions have been identified as having high concentrations of LNG-fueled vessels but limited access to operational BSs: the West Coast of the United States of America (USA), South Africa–Good Hope–Madagascar, Northwest Africa, and Brazil. This selection is based on the geographical distribution of these ships and the existing infrastructure. Hourly greenhouse gas (GHG) emissions have been calculated by considering the …


Geographic Variation In Proteomic Responses To Ocean Acidification In A Cold-Water Coral (Balanophyllia Elegans), Keana A. Richmond Jan 2026

Geographic Variation In Proteomic Responses To Ocean Acidification In A Cold-Water Coral (Balanophyllia Elegans), Keana A. Richmond

Cal Poly Humboldt theses and projects

In the face of a rapidly changing climate, assessing organismal responses to future stressors in the context of current, natural exposure to stress could provide key insights to understanding marine ecosystem resilience. I used Balanophyllia elegans, a cold-water, solitary, azooxanthellate coral as a model to better understand how varying oceanographic conditions across its geographic range have shaped its ability to tolerate and potentially adapt to current and future ocean acidification conditions. I collected B. elegans individuals from four sites across 2,500km of their range and subjected them to two pH treatments to investigate site-specific protein expression in response to …


Revisiting The Life Cycle Of Margalefidinium Polykrikoides Group Iii, Eduardo Pérez-Vega, Kenneth N. Mertens, Pjotr Meyvisch, Margaret R. Mulholland Jan 2026

Revisiting The Life Cycle Of Margalefidinium Polykrikoides Group Iii, Eduardo Pérez-Vega, Kenneth N. Mertens, Pjotr Meyvisch, Margaret R. Mulholland

OES Faculty Publications

Dinoflagellates produce cysts as a strategy to withstand environmental stressors, with nutrient depletion generally considered a key trigger for cyst production. Resting cysts are thick-walled, typically composed of one to several layers, and characterized by a prolonged dormancy period. In contrast, pellicle cysts possess a thin, single wall and exhibit no dormancy or a markedly shorter dormancy than resting cysts of the same species. Margalefidinium polykrikoides produces pellicle and resting cysts, whereas its congener, M. fulvescens, has been shown to produce pumpkin-like structures. Using phase-contrast microscopy, time-lapse microscopy, FlowCam, and attenuated total reflection Fourier transform infrared microspectroscopy (ATR μ-FTIR), …


Efficient Preservation Of Old Methane-Derived Organic Carbon In Deep-Sea Surface Sediments, Rui Bao, Yangli Che, Mingzhi Liu, Naiyu Zhang, Yang Zhou, Lihua Dong, Shen Li, Owen A. Sherwood, Min Yu, Zongheng Chen, Shengxiong Yang, Nan Wang, Longhai Zhu, Jiawang Chen, Mutai Bao, Haoshuai Li, Luonan Chen, Weifeng Wu, Haiyue Ma, David J. Burdige Jan 2026

Efficient Preservation Of Old Methane-Derived Organic Carbon In Deep-Sea Surface Sediments, Rui Bao, Yangli Che, Mingzhi Liu, Naiyu Zhang, Yang Zhou, Lihua Dong, Shen Li, Owen A. Sherwood, Min Yu, Zongheng Chen, Shengxiong Yang, Nan Wang, Longhai Zhu, Jiawang Chen, Mutai Bao, Haoshuai Li, Luonan Chen, Weifeng Wu, Haiyue Ma, David J. Burdige

OES Faculty Publications

Methane released from the subseafloor is significantly attenuated during upward migration, yet the preservation of methane-derived organic carbon (OC) in global deep-sea sediments remains poorly understood. Here, we measured carbon isotopes coupled with temperature-ramped analyses on various methane seepage sediments. Our results reveal a correlation between the radiocarbon (¹⁴)C) content in deep-sea surface sediments and sulfate-methane transition depth. Notably, our findings suggest that a substantial amount of (¹⁴)C-depleted OC may originate from deep-seated methane and is efficiently preserved in surface seepage sediments. We propose that the efficient OC preservation is related to microbial-mediated aggregate formation at the seawater-sediment interface, where …


Chesapeake Bay Water Clarity: Challenges And Successes, Jessica S. Turner, Carl T. Friedrichs, David B. Parrish, Kelsey A. Fall Jan 2026

Chesapeake Bay Water Clarity: Challenges And Successes, Jessica S. Turner, Carl T. Friedrichs, David B. Parrish, Kelsey A. Fall

OES Faculty Publications

The Chesapeake Bay is a large estuarine system spanning multiple jurisdictions and serves as a model for estuarine health worldwide. Historically, nutrient loading degraded water quality, prompting the need for regulation. Water clarity, one component of water quality, is vital for benthic communities and serves as a key indicator of overall ecosystem health. Here, physical resuspension and salinity gradients, nutrient and sediment inputs, production of organic detritus by phytoplankton, and benthic communities all interact to drive clarity patterns, with high spatial variability. Trends over the last 50 years show improvement, though with a temporary increase in organic detritus in response …


Seasonal And Geologic Controls On Submarine Groundwater Discharge-Derived Nutrient Fluxes To Two Coastal Embayments, Moira Taylor, Joseph J. Tamborski, Aaron Alorda-Kleinglass, Nathaniel Maynard Jan 2026

Seasonal And Geologic Controls On Submarine Groundwater Discharge-Derived Nutrient Fluxes To Two Coastal Embayments, Moira Taylor, Joseph J. Tamborski, Aaron Alorda-Kleinglass, Nathaniel Maynard

OES Faculty Publications

Submarine groundwater discharge and porewater exchange are critical but often overlooked sources of nutrients to coastal systems. This study investigates how sediment permeability and summer-winter seasonal dynamics influence the magnitude and biogeochemistry of nutrient fluxes from submarine groundwater discharge and porewater exchange. Reaction rates in the subterranean estuary were used to identify the transformations and drivers of nutrient loading in two geologically distinct embayments in the U.S. East Coast: the highly permeable Peconic Bay estuary (NY), and the surficially fine-grained coastal embayments of the southern Delmarva Peninsula (VA). We applied radium isotope mass balances to distinguish total submarine groundwater discharge …


Diatom Community Response To High And Low Iron Upwelling Plumes In The California Current System, Sveinn V. Einarsson, Kimberly Powell, Claire Till, Tyler Coale, P. Dreux Chappell Jan 2026

Diatom Community Response To High And Low Iron Upwelling Plumes In The California Current System, Sveinn V. Einarsson, Kimberly Powell, Claire Till, Tyler Coale, P. Dreux Chappell

OES Faculty Publications

Diatoms are important primary producers, accounting for most of the oceanic production and carbon export relative to other photosynthetic eukaryotes. There are important differences among diatom species that enable them to proliferate in different environments. Some have nutrient storage capabilities or lower nutrient quotas suited for oligotrophic oceans. Bloom-forming diatoms are typically found in nutrient-rich coastal waters where they respond quickly to nutrient pulses and can influence biogeochemical cycling in the ocean after blooms. As many physiological differences affect biomass and export, it is important to better understand how physical and chemical parameters influence diatom community composition, especially in dynamic …


Modeling Upper Ocean Ecosystem Dynamics In Response To Interannual Sea-Ice Variability In The Western Antarctic Peninsula, Catherine R. Czajka, Jessica S. Turner, Sharon Stammerjohn, Heather H. Kim, Oscar Schofield, Benjamin T. Saenz, Scott C. Doney Jan 2026

Modeling Upper Ocean Ecosystem Dynamics In Response To Interannual Sea-Ice Variability In The Western Antarctic Peninsula, Catherine R. Czajka, Jessica S. Turner, Sharon Stammerjohn, Heather H. Kim, Oscar Schofield, Benjamin T. Saenz, Scott C. Doney

OES Faculty Publications

In the Western Antarctic Peninsula (WAP), marine plankton dynamics are tightly linked to the interannual variability in environmental conditions, including phenological shifts in sea-ice seasonality. To explore these linkages, we use a 1-dimensional vertical ocean-ice-ecosystem model (KPP-Eco-Ice, or KEI) that simulates physical and ecosystem conditions at a continental shelf mooring location in the Palmer Long Term Ecological Research program sampling grid. KEI allows for year-round examination of the ecosystem in a region where in situ observations on the shelf are limited to January. Comparisons are made between seasonal sea-ice retreat, mixed layer depth, primary productivity, and phytoplankton relative abundance, grazing, …


Contribution Of Non-Linear Internal Waves To Marine Net Primary Production Has Been Underestimated, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Shoude Guan, Fuh-Kuo Shiah Jan 2026

Contribution Of Non-Linear Internal Waves To Marine Net Primary Production Has Been Underestimated, Xiaoju Pan, Tung-Yuan Ho, George T. F. Wong, Jen-Hua Tai, Shoude Guan, Fuh-Kuo Shiah

OES Faculty Publications

Field observations in the northern South China Sea (NSCS) indicate that elevated concentrations of chlorophyll a (Chl_a) associated with non-linear internal waves (NIWs) were more pronounced in the subsurface than at the sea-surface. At a given surface Chl_a, the vertically integrated Chl_a in an NIW-active area was 45% higher than that in an area where the NIW activities were minimal. As a result, net primary production (PPeu) estimated from surface Chl_a from remote sensing by using the current Chl_a-based PPeu model (e.g. VGPM) would have underestimated the true value by the same amount. If this correction is …


Testing The Limits Of Provenance Analysis From Basaltic Fluvial Sediment Near Sandvatn, Iceland, As A Mars Analog, Audrey R. Putnam, Kirsten L. Siebach, Michael T. Thorpe, Valerie M. Tu, Elizabeth B. Rampe, Candice C. Bedford, Gelu Costin, Joseph J. Tamborski Jan 2026

Testing The Limits Of Provenance Analysis From Basaltic Fluvial Sediment Near Sandvatn, Iceland, As A Mars Analog, Audrey R. Putnam, Kirsten L. Siebach, Michael T. Thorpe, Valerie M. Tu, Elizabeth B. Rampe, Candice C. Bedford, Gelu Costin, Joseph J. Tamborski

OES Faculty Publications

Detrital sediments that accumulate downstream and are preserved in sedimentary rocks can allow characterization of geologic formations that are inaccessible for spatial or temporal reasons. However, mixing, sorting, and alteration of sediment during transport may complicate reconstruction of protolith characteristics. We test the preservation of three key provenance signals in coarse fluvial sand at a Mars analog watershed in Iceland to determine whether detrital sediments capture (a) watershed magmatic chemical variation, (b) textural indicators of lava-water interaction during eruption and cooling, and (c) hydrothermal alteration. Specifically, we tested whether diagnostic variations in rock mineralogy, chemistry, and texture can be recovered …


Characterizing The Unique Chemical Imprint Of On-Axis, Lower-Temperature Hydrothermal Flow To The Deep Ocean (Southern East Pacific Rise, 16.5°-18.0°S), Laura E. Moore, Randelle M. Bundy, Joseph A. Resing, Scott White, Tamara Baumberger, Peter N. Sedwick, Nathaniel J. Buck, Anson M. Antriasian, Isaac Keohane, Bettina M. Sohst, Sharon L. Walker, Christopher R. German Jan 2026

Characterizing The Unique Chemical Imprint Of On-Axis, Lower-Temperature Hydrothermal Flow To The Deep Ocean (Southern East Pacific Rise, 16.5°-18.0°S), Laura E. Moore, Randelle M. Bundy, Joseph A. Resing, Scott White, Tamara Baumberger, Peter N. Sedwick, Nathaniel J. Buck, Anson M. Antriasian, Isaac Keohane, Bettina M. Sohst, Sharon L. Walker, Christopher R. German

OES Faculty Publications

In addition to high-temperature vents, lower-temperature flow (LTF) (< 300°C) is abundant along mid-ocean ridges and contributes globally-important fluxes of heat and water along with largely-unconstrained geochemical influences on the ocean. We examined the impact of on-axis LTF on the chemical composition of the overlying water column (< 40 m above seafloor) along the 16.5°-18.0°S sector of the ultrafast-spreading southern East Pacific Rise using autonomous underwater vehicle Sentry surveys and conductivity-temperature-depth rosette casts. LTF sites were typically spatially isolated from high-temperature systems and imparted unique chemical signatures to the overlying ocean. Water column samples impacted by LTF exhibited low particulate iron:sulfur ratios and high methane: total-dissolvable manganese ratios, whereas samples influenced by high-temperature venting exhibited opposite trends. We confirmed that LTF imparts a distinct and measurable chemical signature to the water column, independent from high-temperature vents. Isolated, on-axis LTF will be important to consider when assessing hydrothermal circulation impacts upon ocean biogeochemistry.


Autonomous Float Data Reveal Decoupled Trends In Chlorophyll And Stratification In The Indian Ocean, Marufa Ishaque, Sophie Clayton, John Klinck Jan 2026

Autonomous Float Data Reveal Decoupled Trends In Chlorophyll And Stratification In The Indian Ocean, Marufa Ishaque, Sophie Clayton, John Klinck

OES Faculty Publications

Recent studies have shown that the Indian Ocean is warming significantly, but how this warming impacts primary production is largely unresolved due to a relative lack of depth-resolved biological observations. In this study, we have used Biogeochemical-Argo data from 2013 to 2022, comprising over 9,000 individual profiles, to examine regional patterns and trends in depth-integrated chlorophyll, depth-integrated net primary production and stratification in the northern and Equatorial Indian Ocean. Our analysis shows that water column stratification is increasing in the majority of the study area, with the highest rate of increase observed in the western Bay of Bengal. At the …