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2020

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Articles 1 - 30 of 565

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu Dec 2020

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …


2020 - Tennessee Annual Climate Summary, Tennessee Climate Office, East Tennessee State University Dec 2020

2020 - Tennessee Annual Climate Summary, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.


Katanning Research Facility Carbon Footprint Assessment And Strategy To Achieve Carbon Neutrality By 2030, Stephen Wiedemann, Kristina Duff, Mandy Curnow, Perry J. Dolling, David Bicknell, Paul Sanford, John P. Collins, Gavin D'Adhemar Dec 2020

Katanning Research Facility Carbon Footprint Assessment And Strategy To Achieve Carbon Neutrality By 2030, Stephen Wiedemann, Kristina Duff, Mandy Curnow, Perry J. Dolling, David Bicknell, Paul Sanford, John P. Collins, Gavin D'Adhemar

Climate Science Published Reports

As part of the Western Australian Government’s commitment to emissions reduction and the sustainable mitigation of climate change, the Department of Primary Industries and Regional Development (DPIRD) identified that the Katanning Research Facility (KRF) is a significant greenhouse gas (GHG) emitter and that the site provides an opportunity to improve our understanding of emissions arising from agriculture, particularly livestock production. This report presents a baseline organisational carbon footprint assessment and a sustainable emissions reduction strategy with the goal of achieving carbon neutrality for the research facility by 2030.

KRF, with its intensive animal facilities and commercial farm setup, is the …


A Multidisciplinary Approach To Investigate Deep-Pelagic Ecosystem Dynamics In The Gulf Of Mexico Following Deepwater Horizon, April Cook, Andrea Bernard, Kevin M. Boswell, Heather Bracken-Grissom Dr., Marta D'Elia, Sergio Derada, Cole Easson, David English, Ron Eytan, Tamara Frank, Chuanmin Hu, Matt Johnston, Heather Judkins, Chad Lembke, Jose Lopez, Rosanna Milligan, Jon A. Moore, Brad Penta, Nina Pruzinsky, John A. Quinlan, Travis M. Richards, Isabel C. Romero, Mahmood S. Shivji, Michael Vecchione, Max D. Weber, R.J. David Wells, Tracey Sutton Dec 2020

A Multidisciplinary Approach To Investigate Deep-Pelagic Ecosystem Dynamics In The Gulf Of Mexico Following Deepwater Horizon, April Cook, Andrea Bernard, Kevin M. Boswell, Heather Bracken-Grissom Dr., Marta D'Elia, Sergio Derada, Cole Easson, David English, Ron Eytan, Tamara Frank, Chuanmin Hu, Matt Johnston, Heather Judkins, Chad Lembke, Jose Lopez, Rosanna Milligan, Jon A. Moore, Brad Penta, Nina Pruzinsky, John A. Quinlan, Travis M. Richards, Isabel C. Romero, Mahmood S. Shivji, Michael Vecchione, Max D. Weber, R.J. David Wells, Tracey Sutton

Marine & Environmental Sciences Faculty Articles

The pelagic Gulf of Mexico (GoM) is a complex system of dynamic physical oceanography (western boundary current, mesoscale eddies), high biological diversity, and community integration via diel vertical migration and lateral advection. Humans also heavily utilize this system, including its deep-sea components, for resource extraction, shipping, tourism, and other commercial activity. This utilization has had impacts, some with disastrous consequences. The Deepwater Horizon oil spill (DWHOS) occurred at a depth of ∼1500 m (Macondo wellhead), creating a persistent and toxic mixture of hydrocarbons and dispersant in the deep-pelagic (water column below 200 m depth) habitat. In order to assess the …


Marine Geobiology Ocg 5xx, Joanna Burkhardt Dec 2020

Marine Geobiology Ocg 5xx, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Global Ocean Change Ocg 511, Joanna Burkhardt Dec 2020

Global Ocean Change Ocg 511, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Marine Geobiology Ocg 502, Joanna Burkhardt Dec 2020

Marine Geobiology Ocg 502, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White Dec 2020

Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White

School of Earth & Environment Departmental Research

The El Niño Southern Oscillation (ENSO) is highly dependent on coupled atmosphere-ocean interactions and feedbacks, suggesting a tight relationship between ENSO strength and background climate conditions. However, the extent to which background climate state determines ENSO behavior remains in question. Here we present reconstructions of total variability and El Niño amplitude from individual foraminifera distributions at discrete time intervals over the past ~285,000 years across varying atmospheric CO2 levels, global ice volume and sea level, and orbital insolation forcing. Our results show a strong correlation between eastern tropical Pacific Ocean mixed-layer thickness and both El Niño amplitude and central Pacific …


Gravity Waves, Na Lidar, Yafang Guo, Alan Z. Liu Dec 2020

Gravity Waves, Na Lidar, Yafang Guo, Alan Z. Liu

Publications

Vertical energy transports due to dissipating gravity waves in the mesopause region (85–100 km) are analyzed using over 400 h of observational data obtained from a narrow-band sodium wind-temperature lidar located at Andes Lidar Observatory (ALO), Cerro Pachón (30.25°S, 70.73°W), Chile. Sensible heat flux is directly estimated using measured temperature and vertical wind; energy flux is estimated from the vertical wavenumber and frequency spectra of temperature perturbations; and enthalpy flux is derived based on its relationship with sensible heat and energy fluxes. Sensible heat flux is mostly downward throughout the region. Enthalpy flux exhibits an annual oscillation with maximum downward …


Global Ocean Change Ocg 5xx, Joanna Burkhardt Dec 2020

Global Ocean Change Ocg 5xx, Joanna Burkhardt

Library Impact Statements

No abstract provided.


Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek Dec 2020

Influence Of Some Climatic Elements On Radon Concentration In Saeva Dupka Cave, Bulgaria, Peter Nojarov, Petar Stefanov, Karel Turek

International Journal of Speleology

This study reveals the influence of some climatic elements on radon concentration in Saeva Dupka Cave, Bulgaria. The research is based mainly on statistical methods. Radon concentration in the cave is determined by two main mechanisms. The first one is through penetration of radon from soil and rocks around the cave (present all year round, but has leading role during the warm half of the year). The second one is through thermodynamic exchange of air between inside of the cave and outside atmosphere (cold half of the year). Climatic factors that affect radon concentration in the cave are temperatures (air, …


Validation Of Smiles Hcl Profiles Over A Wide Range From The Stratosphere To The Lower Thermosphere, Seidai Nara, Tomohiro O. Sato, Takayoshi Yamada, Tamaki Fujinawa, Kota Kuribayashi, Takeshi Manabe, Lucien Froidevaux, Nathaniel J. Livesey, Kaley A. Walker, Jian Xu, Franz Schreier, Yvan J. Orsolini, Varavut Limpasuvan, Nario Kuno, Yasuko Kasai Dec 2020

Validation Of Smiles Hcl Profiles Over A Wide Range From The Stratosphere To The Lower Thermosphere, Seidai Nara, Tomohiro O. Sato, Takayoshi Yamada, Tamaki Fujinawa, Kota Kuribayashi, Takeshi Manabe, Lucien Froidevaux, Nathaniel J. Livesey, Kaley A. Walker, Jian Xu, Franz Schreier, Yvan J. Orsolini, Varavut Limpasuvan, Nario Kuno, Yasuko Kasai

Marine Science

Hydrogen chloride (HCl) is the most abundant (more than 95 %) among inorganic chlorine compounds Cly in the upper stratosphere. The HCl molecule is observed to obtain long-term quantitative estimations of the total budget of the stratospheric chlorine compounds. In this study, we provided HCl vertical profiles at altitudes of 16 100 km using the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) from space. The HCl vertical profile from the upper troposphere to the lower thermosphere is reported for the first time from SMILES observations; the data quality is quantified by comparison with other measurements and via theoretical error analysis. We used …


Data In Support Of The Paper "Dependence Of Aerosol-Droplet Partitioning On Turbulence In A Laboratory Cloud", Abu Sayeed Md Shawon, Prasanth Prabhakaran, Gregory Kinney, Raymond Shaw, Will Cantrell Dec 2020

Data In Support Of The Paper "Dependence Of Aerosol-Droplet Partitioning On Turbulence In A Laboratory Cloud", Abu Sayeed Md Shawon, Prasanth Prabhakaran, Gregory Kinney, Raymond Shaw, Will Cantrell

Michigan Tech Research Data

No abstract provided.


Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk Dec 2020

Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk

Student Publications

The Arizona toad (Anaxyrus microscaphus) and Jones’ waxy dogbane (Cycladenia humilis var. jonesii) are habitat specialists with historical ranges in the desert southwest and specifically, Zion National Park (ZION). The machine learning method, MaxEnt, constructed species distribution models (SDMs) in ZION for the two study species at 30 m and 900 m spatial resolutions using climate, topographic, and remotely sensed data. Additionally, 900 m forecasting models were constructed to observe the shifts in suitable habitat for the years 2050 and 2070, based off two representative concentration pathway scenarios. Results indicate promising predictive power for both high …


Destabilizing Effects On A Classic Tri-Trophic Oyster Reef Cascade, Virginia R. Schweiss, Chet F. Rakocinski Dec 2020

Destabilizing Effects On A Classic Tri-Trophic Oyster Reef Cascade, Virginia R. Schweiss, Chet F. Rakocinski

Faculty Publications

How interactions among multiple predators affect the stability of trophic cascades is a topic of special ecological interest. To examine factors affecting the stability of the classic tri-trophic oyster reef cascade within a different context, configurations of three predators, including the Gulf toadfish, Gulf stone crab, and oystershell mud crab, were manipulated together with either oyster shell or limestone gravel substrate within a multiple predator effects (MPE) experiment. Additionally, a complimentary set of trait-mediated-indirect interaction (TMII) experiments examined the inhibition of oyster consumption relative to mud-crab size and top predator identity in the absence of other cues and factors. The …


Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen Dec 2020

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen

Dissertations

Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACETWS over areas downgradient and distant (hundreds of km) from …


Carbon Fixation Trends In Eleven Of The World’S Largest Lakes: 2003–2018, Michael Sayers, Karl Bosse, Gary L. Fahnenstiel, Robert Shuchman Dec 2020

Carbon Fixation Trends In Eleven Of The World’S Largest Lakes: 2003–2018, Michael Sayers, Karl Bosse, Gary L. Fahnenstiel, Robert Shuchman

Michigan Tech Publications, Part 1

Large freshwater lakes provide immense value to the surrounding populations, yet there is limited understanding of how these lakes will respond to climate change and other factors. This study uses satellite remote sensing to estimate annual, lake-wide primary production in 11 of the world’s largest lakes from 2003–2018. These lakes include the five Laurentian Great Lakes, the three African Great Lakes, Lake Baikal, and Great Bear and Great Slave Lakes. Mean annual production in these lakes ranged from under 200 mgC/m2/day to over 1100 mgC/m2/day, and the lakes were placed into one of three distinct groups …


Data Generated During The 2018 Lapse-Rate Campaign: An Introduction And Overview, Gijs De Boer, Adam Houston, Jamey D. Jacob, Phillip B. Chilson, Suzanne W. Smith, Brian Argrow, Dale Lawrence, Jack Elston, David Brus, Osku Kemppinen, Petra Klein, Julie K. Lundquist, Sean Waugh, Sean C. C. Bailey, Amy E. Frazier, Michael P. Sama, Christopher Crick, David G. Schmale Iii, James Pinto, Elizabeth A. Pillar-Little, Victoria Natalie, Anders Jensen Dec 2020

Data Generated During The 2018 Lapse-Rate Campaign: An Introduction And Overview, Gijs De Boer, Adam Houston, Jamey D. Jacob, Phillip B. Chilson, Suzanne W. Smith, Brian Argrow, Dale Lawrence, Jack Elston, David Brus, Osku Kemppinen, Petra Klein, Julie K. Lundquist, Sean Waugh, Sean C. C. Bailey, Amy E. Frazier, Michael P. Sama, Christopher Crick, David G. Schmale Iii, James Pinto, Elizabeth A. Pillar-Little, Victoria Natalie, Anders Jensen

Mechanical Engineering Faculty Publications

Unmanned aircraft systems (UASs) offer innovative capabilities for providing new perspectives on the atmosphere, and therefore atmospheric scientists are rapidly expanding their use, particularly for studying the planetary boundary layer. In support of this expansion, from 14 to 20 July 2018 the International Society for Atmospheric Research using Remotely piloted Aircraft (ISARRA) hosted a community flight week, dubbed the Lower Atmospheric Profiling Studies at Elevation – a Remotely-piloted Aircraft Team Experiment (LAPSE-RATE; de Boer et al., 2020a). This field campaign spanned a 1-week deployment to Colorado's San Luis Valley, involving over 100 students, scientists, engineers, pilots, and outreach coordinators. These …


Large Global Variations In Measured Airborne Metal Concentrations Driven By Anthropogenic Sources, Jacob Mcneill, Randal V. Martin, Nofel Lagrosas, 35 Co-Authors Dec 2020

Large Global Variations In Measured Airborne Metal Concentrations Driven By Anthropogenic Sources, Jacob Mcneill, Randal V. Martin, Nofel Lagrosas, 35 Co-Authors

SOSE Affiliate: Manila Observatory

Globally consistent measurements of airborne metal concentrations in fine particulate matter (PM2.5) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM2.5 filter samples (N ~ 800 from 19 locations) collected from a globally distributed surface particulate matter sampling network (SPARTAN) between January 2013 and April 2019 were analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100–3000 compared …


Seasonal Variation Of Vertical Heat And Energy Fluxes Due To Dissipating Gravity Waves In The Mesopause Region Over The Andes, Yafang Guo, Alan Z. Liu Dec 2020

Seasonal Variation Of Vertical Heat And Energy Fluxes Due To Dissipating Gravity Waves In The Mesopause Region Over The Andes, Yafang Guo, Alan Z. Liu

Publications

Vertical energy transports due to dissipating gravity waves in the mesopause region (85–100 km) are analyzed using over 400 h of observational data obtained from a narrow-band sodium wind-temperature lidar located at Andes Lidar Observatory (ALO), Cerro Pachón (30.25°S, 70.73°W), Chile. Sensible heat flux is directly estimated using measured temperature and vertical wind; energy flux is estimated from the vertical wavenumber and frequency spectra of temperature perturbations; and enthalpy flux is derived based on its relationship with sensible heat and energy fluxes. Sensible heat flux is mostly downward throughout the region. Enthalpy flux exhibits an annual oscillation with maximum downward …


Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith Dec 2020

Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith

National Drought Mitigation Center: Faculty Publications

Drought is a familiar climatic phenomenon in the United States Southwest, with complex human-environment interactions that extend beyond just the physical drought events. Due to continued climate variability and change, droughts are expected to become more frequent and/or severe in the future. Decision-makers are charged with mitigating and adapting to these more extreme conditions and to do that they need to understand the specific impacts drought has on regional and local scales, and how these impacts compare to historical conditions. Tremendous progress in drought monitoring strategies has occurred over the past several decades, with more tools providing greater spatial and …


Early Life History Of Tarpon (Megalops Atlanticus) In South Carolina Estuaries: Assessment Of Juvenile Recruitment And Validity Of Aging And Back-Calculation Methods, Garrett M. Elmo Dec 2020

Early Life History Of Tarpon (Megalops Atlanticus) In South Carolina Estuaries: Assessment Of Juvenile Recruitment And Validity Of Aging And Back-Calculation Methods, Garrett M. Elmo

Electronic Theses and Dissertations

No abstract provided.


Weather And Climate Summary And Forecast: December 2020 Report, Gregory V. Jones Dec 2020

Weather And Climate Summary And Forecast: December 2020 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for December 2020. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.


Parametric Model Development For Heterogeneous Atmospheric Conditions, Daniel Paul Greenway Dec 2020

Parametric Model Development For Heterogeneous Atmospheric Conditions, Daniel Paul Greenway

Electronic Theses and Dissertations

No abstract provided.


A Colonized Cop: Indigenous Exclusion And Youth Climate Justice Activism At The United Nations Climate Change Negotiations, Corrie Grosse, Brigid Mark Dec 2020

A Colonized Cop: Indigenous Exclusion And Youth Climate Justice Activism At The United Nations Climate Change Negotiations, Corrie Grosse, Brigid Mark

Environmental Studies Faculty Publications

Youth activists around the world are demanding urgent climate action from elected leaders. The annual United Nations climate change negotiations, known as COPs, are key sites of global organizing and hope for a comprehensive approach to climate policy. Drawing on participant observation and in-depth interviews at COP25 in 2019, this research examines youth climate activists’ priorities, frustrations and hopes for creating just climate policy. Youth are disillusioned with the COP process and highlight a variety of ways through which the COP perpetuates colonial power structures that marginalize Indigenous peoples and others fighting for justice. This is intersectional exclusion - the …


Cost-Effective Gnss Hardware For High-Accuracy Surveys And Its Prospects For Post-Processed Kinematic (Ppk) And Precise Point Positioning (Ppp) Strategies, Johnson Olusegun Oguntuase Dec 2020

Cost-Effective Gnss Hardware For High-Accuracy Surveys And Its Prospects For Post-Processed Kinematic (Ppk) And Precise Point Positioning (Ppp) Strategies, Johnson Olusegun Oguntuase

Dissertations

This dissertation determines for the first time the vertical accuracy achievable with low-cost mass-market multi-frequency, multi-GNSS (LM3GNSS) receivers, and antennas in the context of Ellipsoid Reference Survey (ERS), usually employed in bathymetric operations aboard survey platforms. LM3GNSS receivers are relatively new in the market, and their emergence is driven by the automobile industry and several mass-market applications requiring location-based solutions at high accuracies. It is foreseeable that emerging hydrographic survey platforms such as autonomous surface vehicles, small unmanned aircraft, crowd-sourced bathymetric platforms, and offshore GNSS buoy will find LM3GNSS receivers attractive since they are power- and cost-effective (often less than …


Seasonal Variability Of Upwelling And Downwelling Surface Current Patterns Near A Small Coastal Embayment, Nicholas Trautman Dec 2020

Seasonal Variability Of Upwelling And Downwelling Surface Current Patterns Near A Small Coastal Embayment, Nicholas Trautman

Physics

Upwelling in coastal embayments is important to a variety of physical and biological processes. Despite their ubiquity, circulation patterns in small bays (width and length scales ≤ 20 km) in eastern boundary current upwelling systems are relatively understudied compared to their larger counterparts. In this study, we apply a conditional averaging technique to investigate upwelling- and downwelling-driven circulation in a small coastal embayment located in Central California [San Luis Obispo (SLO) Bay]. We also investigate intraseasonal differences in the current patterns in SLO Bay. Conditional averaging reveals distinct intraseasonal differences and features that are obscured by traditional seasonal averages when …


In The Margins: Reconsidering The Range And Contribution Of Diazotrophs In Nearshore Environments, Corday R. Selden Dec 2020

In The Margins: Reconsidering The Range And Contribution Of Diazotrophs In Nearshore Environments, Corday R. Selden

OES Theses and Dissertations

Dinitrogen (N2) fixation enables primary production and, consequently, carbon dioxide drawdown in nitrogen (N) limited marine systems, exerting a powerful influence over the coupled carbon and N cycles. Our understanding of the environmental factors regulating its distribution and magnitude are largely based on the range and sensitivity of one genus, Trichodesmium. However, recent work suggests that the niche preferences of distinct diazotrophic (N2 fixing) clades differ due to their metabolic and ecological diversity, hampering efforts to close the N budget and model N2 fixation accurately. Here, I explore the range of N2 fixation …


Climate Change Games As Boundary Objects: Fostering Dialogic Communication Within Stakeholder Engagement, Megan L. Mckittrick Dec 2020

Climate Change Games As Boundary Objects: Fostering Dialogic Communication Within Stakeholder Engagement, Megan L. Mckittrick

English Theses & Dissertations

Rising waters and the increasing devastation of flood events make coastal resilience a significant issue in the Hampton Roads region of Virginia, particularly in the city of Norfolk. Enhancing resilience requires ongoing stakeholder engagement designed to invite dialogue while encouraging cross-jurisdictional collaboration and comprehensive problem-solving. Climate change games have been employed to support these endeavors. This dissertation provides a response to the following research questions: 1) What is the origin of the climate change game genre? 2) Why are key stakeholders in coastal resilience using climate change games? And 3) how do these games operate for these key stakeholders? To …


Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins Dec 2020

Sodium-Calcium Ratios In The Planktic Foraminifera Trilobatus Sacculifer As A Proxy For Sea Surface Salinity, Colton Steele Watkins

OES Theses and Dissertations

Recent culture and field studies have found a significant positive correlation between seawater salinity and the incorporation of sodium into foraminiferal calcite, suggesting a potential new proxy for reconstructing past changes in sea surface salinity (SSS) (Mezger et al., 2016 and Bertlich et al., 2018). In order to test the applicability of this new proxy in an open-ocean setting, Na/Ca ratios in the planktic foraminifera Trilobatus sacculifer (T. sacculifer Na/Ca) were measured from a suite of sediment core tops spanning a natural salinity gradient from the North Atlantic subtropical gyre to the South Atlantic subtropical gyre. Initial results from …