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Articles 1 - 30 of 11242

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Creating Singapore’S Longest Monthly Rainfall Record From 1839 To The Present, Elaine Gao, Bertrand Timbal, Fiona Williamson Dec 2019

Creating Singapore’S Longest Monthly Rainfall Record From 1839 To The Present, Elaine Gao, Bertrand Timbal, Fiona Williamson

Research Collection School of Social Sciences

Currently,the identification of decadal variability is limited by the lack of long-termmeteorological datasets; Singapore’s reliable contemporary network of automaticmeteorological stations (AWS) provides only about 30 years of rainfall data for thewhole island. In this study, rainfall data, sourced fromhistorical archives and recording monthly rainfall pre-dating the start ofofficial MacRitchie observations, are compiled from various locations acrossthe island. By making use of the contemporary AWS network, we evaluate thespatial relationship of rainfall between the historical sites and the currentMacRitchie site. This enables us to reconstruct historical rainfall atMacRitchie using the archive data, thereby building a single-location extendedrainfall record (though ...


Isolution 1.0: An Isotope Evolution Model Describing The Stable Oxygen (Δ18O) And Carbon (Δ13C) Isotope Values Of Speleothems, Michael Deininger, Denis Scholz Jan 2019

Isolution 1.0: An Isotope Evolution Model Describing The Stable Oxygen (Δ18O) And Carbon (Δ13C) Isotope Values Of Speleothems, Michael Deininger, Denis Scholz

International Journal of Speleology

Stable oxygen and carbon isotope ratios (δ13C and δ18O) are the most applied climate and environmental proxies in speleothems allowing to infer past changes in cave drip water δ13C and δ18O related to climate and environmental variations from above the cave. However, disequilibrium isotope fractionation processes can modify δ13C and δ18O values in speleothems, which is in most cases difficult to estimate due to inter-dependencies on various cave specific parameter. To better understand the effect of these disequilibrium isotope fractionation processes proxy system models were developed in recent ...


Planting Date, Hybrid Maturity, And Weather Effects On Maize Yield And Crop Stage, M. E. Baum, S. V. Archontoulis, M. A. Licht Jan 2019

Planting Date, Hybrid Maturity, And Weather Effects On Maize Yield And Crop Stage, M. E. Baum, S. V. Archontoulis, M. A. Licht

Agronomy Publications

Unfavorable weather conditions frequently cause farmers to plant maize (Zea mays L.) outside the optimum planting timeframe. We analyzed maize yield and phenology from a multilocation, year, hybrid relative maturity, and planting date experiment performed in Iowa, USA. Our objectives were to determine the optimum combination of planting date and relative maturity to maximize maize grain yield per environment and to elucidate the risk associated with the use of “full-season hybrids” when planting occurs beyond the optimum planting date. Analysis of variance (ANOVA) attributed 70% of the variability in grain yield to planting date and only 10% to relative maturity ...


Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang Jan 2019

Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang

Adam Liska Papers

Crop residue is an abundant resource for the potential production of biofuels, but a better understanding of its use on net carbon emissions must be developed to mitigate climate change. This analysis combines two established crop growth models (Hybrid-Maize and SoySim) with a simple soil and crop residue respiration model to estimate daily ecosystem respiration (ERe) from maize and soybean; ERe was estimated to be the sum of CO2 emissions from the oxidation of the growing crop, crop residue, and soil organic carbon (SOC). Model-estimated CO2 fluxes from irrigated continuous maize and irrigated maize–soybean cropping systems in ...


Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis Dec 2018

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 ...


Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh Dec 2018

Coupling Between Land–Ocean–Atmosphere And Pronounced Changes In Atmospheric/Meteorological Parameters Associated With The Hudhud Cyclone Of October 2014, Akshansa Chauhan, Rajesh Kumar, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

India is vulnerable to all kinds of natural hazards associated with land, ocean, biosphere, atmosphere, and snow/glaciers. These natural hazards impact large areas and the population living in the affected regions. India is surrounded by ocean on three sides and is vulnerable to cyclonic activities. Every year cyclones hit the east and west coasts of India, affecting the population living along the coasts and infrastructure and inland areas. The extent of the affected inland areas depends on the intensity of the cyclone. On 12 October 2014, a strong cyclone “Hudhud” hit the east coast of India that caused a ...


Analysis Of Land Surface Temperature Over Urban Landcover Types Using Satellite Remote Sensing And Ground-Based Applications, Makini Valentine, Justine Ginchereau Dec 2018

Analysis Of Land Surface Temperature Over Urban Landcover Types Using Satellite Remote Sensing And Ground-Based Applications, Makini Valentine, Justine Ginchereau

Publications and Research

Urban areas have discrete differences in their land surface temperatures (LST) compared to rural areas. These regions are covered with impermeable materials with less vegetation and moisture. Consequently, this phenomenon causes major thermal intensities of different land surfaces, negatively impact people and environment. The objective of this project is to examine and to compare land surface temperature obtained from in-situ data and satellite-based observations in order to understand the diurnal variation and heat transfer at each surface type. The study utilizes series of hand held thermal infrared cameras and one Unmanned Aerial Vehicle (UAV) infrared camera to find land surface ...


Summertime Connecticut River Water Pathways And Wind Impacts, Yan Jia, Michael M. Whitney Dec 2018

Summertime Connecticut River Water Pathways And Wind Impacts, Yan Jia, Michael M. Whitney

Department of Marine Sciences

Long Island Sound is a large macrotidal estuary. Connecticut River as the primary freshwater source enters near the sound’s mouth. The summertime pathways of river water under low discharge and mild wind conditions are studied through both numerical simulations with a passive dye pulse and field surface drifter observations. Within the 19-day modeling analysis period, a third of the river dye pulse moves up-estuary with the near-bottom dense inflow into central and western sound with a spring-neap tidal modulation; another third leaves the sound with the near-surface outflow towards the continental shelf through Block Island Sound. The latter pathway ...


Multispectral Classification Of Gulf Of Maine Surface Waters: Seasonal And Interannual Variability, Brianna M. King Dec 2018

Multispectral Classification Of Gulf Of Maine Surface Waters: Seasonal And Interannual Variability, Brianna M. King

Electronic Theses and Dissertations

Bio-optically, surface waters of the northeastern US continental shelf are strongly heterogeneous, exhibiting highly variable distributions in both time and space of suspended sediment, colored dissolved organic matter (CDOM), and phytoplankton concentration and community structure. These render the standard global NASA satellite chlorophyll algorithm suspect. However, spectral signatures of the water are well quantified by the actual satellite-based multispectral reflectance (Rrs) measurements. Here, we use 6 bands of Rrs measurements from 19 years (1998-2016) of monthly composite SeaWiFS and MODIS data to identify the spectral signatures of dominant water types present over the northeast shelf. A merged multivariate clustering approach ...


Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern Dec 2018

Methanogens, Plausible Extraterrestrial Life Forms On Mars, And Their Tolerance To Increasing Concentrations Of Illite Clay, Chandler Kern

Biological Sciences Undergraduate Honors Theses

Methanogens, some of Earth’s most primitive prokaryotic organisms, are candidates for possible life forms capable of inhabiting Mars. Specifically, four different species (Methanobacterium formicicum, Methanococcus maripaludis, Methanosarcina barkeri, Methanothermobacter wolfeii) were analyzed for their tolerance to the presence of illite clay. Illite is a crystalline mineral that has been identified from regions of Mars’s surface. Results indicated that all four species grew with some success in the illite at different concentrations. This experimentation with methanogens’ abilities to survive and reproduce in the presence of illite allows for a more accurate understanding of the potential capability of microbial growth ...


Associated Dataset: Ocean Circulation Causes Strong Variability In The Mid-Atlantic Bight Nitrogen Budget, Marjorie A.M. Friedrichs, Pierre St-Laurent Dec 2018

Associated Dataset: Ocean Circulation Causes Strong Variability In The Mid-Atlantic Bight Nitrogen Budget, Marjorie A.M. Friedrichs, Pierre St-Laurent

Data

The dataset includes model outputs used in the associated publication (Friedrichs et al.), which used the United States Eastern Continental Shelf (USECoS) biogeochemical model embedded in the Regional-Ocean-Modeling-System (ROMS) to examine the impact of the oceanic circulation on the nitrogen budget of the Mid-Atlantic Bight (MAB). The model simulation covers the period 2004 to 2008 and is fully described in the associated publication. The model simulation highlights that the horizontal along-shelf and across-shelf fluxes dominate the spatiotemporal variability of net community production (NCP) in the MAB. The highest NCP is found in a year when inorganic nitrogen entering from across ...


Investigating Smoke Aerosol Emission Coefficients Using Modis Active Fire And Aerosol Products – A Case Study In The Conus And Indonesia, Xiaoman Lu, Xiaoyang Zhang, Fangjun Li, Mark Cochrane Dec 2018

Investigating Smoke Aerosol Emission Coefficients Using Modis Active Fire And Aerosol Products – A Case Study In The Conus And Indonesia, Xiaoman Lu, Xiaoyang Zhang, Fangjun Li, Mark Cochrane

Global Land Surface Season Data Sets

This data set is in relation to the paper of the same title, which has been submitted to the Journal of Geophysical Research: Biogeosciences.

Instructions for viewing the data in “Readme.txt”





The Advanced Mesospheric Temperature Mapper: Remote Sensing Of The Nighttime Oh Layer During The Deepwave Campaign, Pattilyn Mclaughlin Dec 2018

The Advanced Mesospheric Temperature Mapper: Remote Sensing Of The Nighttime Oh Layer During The Deepwave Campaign, Pattilyn Mclaughlin

All Graduate Plan B and other Reports

The Advanced Mesospheric Temperature Mapper [AMTM] is a remote sensing instrument developed at Utah State University to map temperature structures in the hydroxyl airglow emission at ~87 km. These maps can then be used to quantify wave field characteristics and to observe general climatology trends. Two recent campaigns that it has been involved with are the DEEPWAVE campaign in Lauder, New Zealand and the Super Soaker campaign in Fairbanks, Alaska.

The Deep Propagating Gravity Wave Experiment, “DEEPWAVE” was an international measurement and modeling program intended to characterize the generation and propagation of a broad range of atmospheric gravity waves with ...


Designing A Protected Area To Safeguard Imperiled Species From Urbanization, Stephanie S. Romanach, Brad Stith, Fred A. Johnson Dec 2018

Designing A Protected Area To Safeguard Imperiled Species From Urbanization, Stephanie S. Romanach, Brad Stith, Fred A. Johnson

USGS Staff -- Published Research

Reserve design is a process that can address ecological, social, and political factors to identify parcels of land needed to sustain wildlife populations and other natural resources. Acquisition of parcels for a large terrestrial reserve is difficult because it typically occurs over a long timeframe and thus invokes consideration of future conditions such as climate and urbanization changes. In central Florida, the U.S. government has authorized a new protected area, the Everglades Headwaters National Wildlife Refuge. The new refuge will host important threatened and endangered species and habitats, and will be located to allow for species adaptation from climate ...


Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane Dec 2018

Along-Shelf Connectivity And Circumpolar Gene Flow In Antarctic Silverfish (Pleuragramma Antarctica), Jilda Alicia Caccavo, Chiara Papetti, Maj Wetjen, Rainer Knust, Julian R. Ashford, Lorenzo Zane

OEAS Faculty Publications

The Antarctic silverfish (Pleuragramma antarctica) is a critically important forage species with a circumpolar distribution and is unique among other notothenioid species for its wholly pelagic life cycle. Previous studies have provided mixed evidence of population structure over regional and circumpolar scales. The aim of the present study was to test the recent population hypothesis for Antarctic silverfish, which emphasizes the interplay between life history and hydrography in shaping connectivity. A total of 1067 individuals were collected over 25 years from different locations on a circumpolar scale. Samples were genotyped at fifteen microsatellites to assess population differentiation and genetic structuring ...


Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard Dec 2018

Margaret White Springs Recharge Study, Buffalo National River, North-Central Arkansas, Usa, Ashlon Elizabeth Leonard

Theses and Dissertations

Margaret White Springs (MWS) is one of the largest springs in the middle section of the Buffalo National River (BNR) and contributes several tens of cubic feet per second of flow to river discharge on average, yet the source of the water has not been fully studied or documented. The spring is located approximately 4 miles downstream from Robertson Hole, a losing reach of the river. At Robertson Hole the river loses a significant amount of flow to groundwater, which during the dry season (summer) can be as much as 100%. Flow in the main channel is re-established at MWS ...


Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl Dec 2018

Dynamics Of Prochlorococcus Diversity And Photoacclimation During Short-Term Shifts In Water Column Stratification At Station Aloha, Anne W. Thompson, Ger Van Den Engh, Nathan A. Ahlgren, Kathleen Kouba, Samantha Ward, Samuel T. Wilson, David M. Karl

Biology Faculty Publications and Presentations

The cyanobacterium Prochlorococcus is the dominant phototroph in surface waters of the vast oligotrophic oceans, the foundation of marine food webs, and an important component of global biogeochemical cycles. The prominence of Prochlorococcus across the environmental gradients of the open ocean is attributed to its extensive genetic diversity and flexible chlorophyll physiology, enabling light capture over a wide range of intensities. What remains unknown is the balance between temporal dynamics of genetic diversity and chlorophyll physiology in the ability of Prochlorococcus to respond to a variety of short (approximately 1 day) and longer (months to year) changes in the environment ...


Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray Dec 2018

Aliased Tidal Variability In Mesoscale Sea Level Anomaly Maps, Edward Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Sea level anomaly (SLA) maps are routinely produced by objective analysis of data from the constellation of satellite altimeter missions in operation since 1992. Beginning in 2014, changes in the Data Unification and Altimeter Combination System (DUACS) used to create the SLA maps resulted in improved spatial resolution of mesoscale variability, but it also increased the levels of aliased tidal variability compared to the methodology employed prior to 2014. The present work investigates the magnitude and spatial distribution of these tidal signals, which are typically smaller than 1 cmin the open ocean but can reach tens of centimeters in the ...


Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté Nov 2018

Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, Caitlyn R. Witkowski, Johan W. H. Weijers, Brian S. Blais, Stefan Schouten, Jaap S. Sinninghe Damsté

Science and Technology Faculty Journal Articles

Past changes in the atmospheric concentration of carbon dioxide (PCO2) have had a major impact on earth system dynamics; yet, reconstructing secular trends of past PCO2 remains a prevalent challenge in paleoclimate studies. The current long-term PCO2reconstructions rely largely on the compilation of many different proxies, often with discrepancies among proxies, particularly for periods older than 100 million years (Ma). Here, we reconstructed Phanerozoic PCO2 from a single proxy: the stable carbon isotopic fractionation associated with photosynthesis (Ɛp) that increases as PCO2 increases. This concept has been widely applied to alkenones, but here, we expand ...


Earth-Observation-Based Estimation And Forecasting Of Particulate Matter Impact On Solar Energy In Egypt, Panagiotis G. Kosmopoulos, Stelios Kazadzis, Hesham El-Askary, Michael Taylor, Antonis Gkikas, Emmanouil Proestakis, Charalampos Kontoes, Mohamed Mostafa El-Khayat Nov 2018

Earth-Observation-Based Estimation And Forecasting Of Particulate Matter Impact On Solar Energy In Egypt, Panagiotis G. Kosmopoulos, Stelios Kazadzis, Hesham El-Askary, Michael Taylor, Antonis Gkikas, Emmanouil Proestakis, Charalampos Kontoes, Mohamed Mostafa El-Khayat

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study estimates the impact of dust aerosols on surface solar radiation and solar energy in Egypt based on Earth Observation (EO) related techniques. For this purpose, we exploited the synergy of monthly mean and daily post processed satellite remote sensing observations from theMODerate resolution Imaging Spectroradiometer (MODIS), radiative transfer model (RTM) simulations utilizing machine learning, in conjunction with 1-day forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). As cloudy conditions in this region are rare, aerosols in particular dust, are the most common sources of solar irradiance attenuation, causing performance issues in the photovoltaic (PV) and concentrated solar power ...


Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos Nov 2018

Impacts Of Pacific Ssts On Atmospheric Circulations Leading To California Winter Precipitation Variability: A Diagnostic Modeling, Boksoon Myoung, Sang-Wook Yeh, Jinwon Kim, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

One of the primary meteorological causes of the winter precipitation deficits and droughts in California (CA) is anomalous developments and maintenance of upper-tropospheric ridges over the northeastern Pacific. In order to understand and find the key factors controlling the winter precipitation variability in CA, the present study examines two dominant atmospheric modes of the 500 hPa geopotential height in the Northern Hemisphere using an Empirical Orthogonal Function (EOF) and their associated large-scale circulation patterns for the last 41 winters (1974/75–2014/15). Explaining 17.5% of variability, the second mode (EOF2) shows strong anti-cyclonic circulations in the North Pacific ...


Fine-Scale Droplet Clustering In Atmospheric Clouds: 3d Radial Distribution Function From Airborne Digital Holography, Michael L. Larsen, Raymond Shaw, Alexander Kostinski, Susanne Glienke Nov 2018

Fine-Scale Droplet Clustering In Atmospheric Clouds: 3d Radial Distribution Function From Airborne Digital Holography, Michael L. Larsen, Raymond Shaw, Alexander Kostinski, Susanne Glienke

Department of Physics Publications

The extent of droplet clustering in turbulent clouds has remained largely unquantified, and yet is of possible relevance to precipitation formation and radiative transfer. To that end, data gathered by an airborne holographic instrument are used to explore the three-dimensional spatial statistics of cloud droplet positions in homogeneous stratiform boundary-layer clouds. The three-dimensional radial distribution functions g(r) reveal unambiguous evidence of droplet clustering. Three key theoretical predictions are observed: the existence of positive correlations, onset of correlation in the turbulence dissipation range, and monotonic increase of g(r) with decreasing r. This implies that current theory captures the essential ...


Evaluation Of Spatial Generalization Characteristics Of A Robust Classifier As Applied To Coral Reef Habitats In Remote Islands Of The Pacific Ocean, Justin J. Gapper, Hesham El-Askary, Erik J. Linstead, Thomas Piechota Nov 2018

Evaluation Of Spatial Generalization Characteristics Of A Robust Classifier As Applied To Coral Reef Habitats In Remote Islands Of The Pacific Ocean, Justin J. Gapper, Hesham El-Askary, Erik J. Linstead, Thomas Piechota

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study was an evaluation of the spectral signature generalization properties of coral across four remote Pacific Ocean reefs. The sites under consideration have not been the subject of previous studies for coral classification using remote sensing data. Previous research regarding using remote sensing to identify reefs has been limited to in-situ assessment, with some researchers also performing temporal analysis of a selected area of interest. This study expanded the previous in-situ analyses by evaluating the ability of a basic predictor, Linear Discriminant Analysis (LDA), trained on Depth Invariant Indices calculated from the spectral signature of coral in one location ...


Pulsed Fiber Optics Lasers As Highly Sensitive Sensors, Hanieh Afkhamiardakani Nov 2018

Pulsed Fiber Optics Lasers As Highly Sensitive Sensors, Hanieh Afkhamiardakani

Shared Knowledge Conference

An interferometer or resonator is a device in which optical beams of specific frequencies circulate with minimal losses. These losses are completely compensated by the gain inside a laser resonator. A small perturbation introduced inside the laser can affect its frequency, which in turns becomes a metric of that perturbation. The perturbation is usually caused by an electric or magnetic field, rotation, acceleration, nonlinear index of refraction etc. Tiny changes of optical frequency are monitored by superimposing the laser field and a reference field (from the same laser) on a detector. This technique requires creating a laser in which two ...


Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh Nov 2018

Elevated Black Carbon Concentrations And Atmospheric Pollution Around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground And Satellite Data, Ramesh Singh, Sarvan Kumar, Abhay K. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The tropospheric NO2 concentration from OMI AURA always shows high concentrations of NO2 at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations ...


Managing Lake Fertility Within The Guidelines Of A Nutrient Management Plan And Based On Algal Nutrient Limitation, Bradley J. Austin, J. Thad Scott, Brian E. Haggard Nov 2018

Managing Lake Fertility Within The Guidelines Of A Nutrient Management Plan And Based On Algal Nutrient Limitation, Bradley J. Austin, J. Thad Scott, Brian E. Haggard

Technical Reports

The specific objectives were to first, monitor nutrients, algal biomass, and water clarity in lakes Cove, Spring, and Wedington. Second, evaluate whether algal growth in each of the lakes was limited by N, P, or both N and P. This research was conducted to help USFS better manage lake fertilization to maximize algal growth and improve the fisheries within these lakes.


Designing Climate Policy: Lessons From The Renewable Fuel Standard And The Blend Wall, Gabriel E. Lade, C.-Y. Cynthia Lin Lawell, Aaron Smith Nov 2018

Designing Climate Policy: Lessons From The Renewable Fuel Standard And The Blend Wall, Gabriel E. Lade, C.-Y. Cynthia Lin Lawell, Aaron Smith

Economics Working Papers

Many policies mandate renewable energy production to combat global climate change. These policies often differ significantly from first-best policy prescriptions. Among the largest renewable energy mandates enacted to date is the Renewable Fuel Standard (RFS), which mandates biofuel consumption far beyond what is feasible with current technology and infrastructure. In this article, we critically review the methods used by the Environmental Protection Agency to project nearand long-term compliance costs under the RFS, and draw lessons from the RFS experience to date that would improve the program’s efficiency. The lessons are meant to inform both future RFS rulemaking and the ...


Temporal Dynamics Of Lipid And Fatty Acid Characteristics Of Gulf Menhaden, Brevoortia Patronus In The Northern Gulf Of Mexico, Robert R. Leaf, Jesse Trushenski, Nancy Brown-Peterson, Michael J. Andres Nov 2018

Temporal Dynamics Of Lipid And Fatty Acid Characteristics Of Gulf Menhaden, Brevoortia Patronus In The Northern Gulf Of Mexico, Robert R. Leaf, Jesse Trushenski, Nancy Brown-Peterson, Michael J. Andres

Faculty Publications

Gulf Menhaden, Brevoortia patronus, in the northern Gulf of Mexico support a large commercial fishery and are thought to play an important trophic role in the coastal ecosystem. The temporal dynamics of both fatty acid and oil content have a direct impact on the value of Gulf Menhaden to predators and to the fishery. In this work, we describe how oil content of Gulf Menhaden varies with season, sex, age, condition, and tissue and investigate how fatty acid composition of mature (≥" role="presentation">

137.5 mm FL) female tissues varies with season, month, and tissue type. We found pronounced temporal ...


A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus Nov 2018

A Deep Eastern Equatorial Pacific Thermocline During The Last Glacial Maximum, H. L. Ford, C. L. Mcchesney, J. E. Hertzberg, J. F. Mcmanus

OEAS Faculty Publications

The mean state and variability of the tropical Pacificis influenced by the depth of the thermocline. During the Last Glacial Maximum (~21,000 years ago), the zonal sea surface temperature gradient across the equatorial Pacific was reduced and productivity was generally lower than modern. To understand the thermocline depth’s role in determining the Last Glacial Maximum tropical mean state, we reconstruct the upper ocean δ18O profile from multiple species of planktic foraminifera. We synthesize existing records of surface and subsurface dwelling foraminifera to reconstruct the vertical δ18O gradient throughout the eastern equatorial Pacific. We find ...


Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman Oct 2018

Eddy Flux Measurements Of Sulfur Dioxide Deposition To The Sea Surface, Jack G. Porter, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Deposition to the sea surface is a major atmospheric loss pathway for many important trace gases, such as sulfur dioxide (SO2). The air–sea transfer of SO2 is controlled entirely on the atmospheric side of the air–sea interface due to high effective solubility and other physical– chemical properties. There have been few direct field measurements of such fluxes due to the challenges associated with making fast-response measurements of highly soluble trace gases at very low ambient levels. In this study, we report direct eddy covariance air–sea flux measurements of SO2, sensible heat, water vapor, and momentum. The measurements ...