Planting Date, Hybrid Maturity, And Weather Effects On Maize Yield And Crop Stage, 2019 Iowa State University
Planting Date, Hybrid Maturity, And Weather Effects On Maize Yield And Crop Stage, M. E. Baum, S. V. Archontoulis, M. A. Licht
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 ...
Molecular Fossils From Phytoplankton Reveal Secular Pco2 Trend Over The Phanerozoic, 2018 Utrecht University
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 ...
Designing Climate Policy: Lessons From The Renewable Fuel Standard And The Blend Wall, 2018 Iowa State University
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 ...
Local Warming In Low Latitude Locations: A Time Series Analysis, 2018 Anderson University
Local Warming In Low Latitude Locations: A Time Series Analysis, Ryan Pittman
Rose-Hulman Undergraduate Mathematics Journal
Global warming is a well-known and well-studied phenomenon pertaining to a gradual increase of average global temperatures over time. Many global warming mathematical models make certain assumptions regarding the factors that impact global temperature. These assumptions include effects from increased global carbon dioxide levels in the atmosphere and the melting ice sheets, among others. This paper draws conclusions about temperature changes without the assumptions needed for the global warming mathematical models. Instead of using computer models to project temperatures on a global scale, 33 low-latitude locations in the southern United States were individually studied to see if each one has ...
The 'New Normal' Of Flooding In Portsmouth, Virginia: Perspectives, Experiences, And Adaptive Responses Of Residents And Business Owners In Low To Moderate-Income Communities, 2018 Old Dominion University
The 'New Normal' Of Flooding In Portsmouth, Virginia: Perspectives, Experiences, And Adaptive Responses Of Residents And Business Owners In Low To Moderate-Income Communities, Donta Council, Michelle Covi, Wie Yusuf, Joshua Behr, Makayla Brown, Old Dominion University Resilience Collaborative, Virginia Sea Grant
Presentations, Lectures, Posters, Reports
[First three paragraphs from the Summary]
This project is a part of a broader initiative - the Resilience Adaptation Feasibility Tool (RAFT) - that addresses the daunting challenges coastal communities are facing related to sea level rise and climate change (more information about RAFT is available here: https://ien.virginia.edu/raft).
This aim of this project was to investigate how residents and business owners in low-to-moderate income communities in Portsmouth, Virginia cope with flooding, and to assess implications for how the local government can better engage with residents to better meet their information needs so they can be more resilient to ...
A Climatological Dataset Of Nutrient, Chlorophyll, And Particulate Matter Distributions On The Ross Sea Continental Shelf Derived From Cruise-Based Measurements Spanning 1967 To 2016, 2018 Virginia Institute of Marine Science
A Climatological Dataset Of Nutrient, Chlorophyll, And Particulate Matter Distributions On The Ross Sea Continental Shelf Derived From Cruise-Based Measurements Spanning 1967 To 2016, Walker O. Smith Jr., Daniel E. Kaufman
This dataset includes data used in the publication Smith and Kaufman (2018), Progress in Oceanography, which examines the temporal and spatial distributions of nutrients and particulate matter in the Ross Sea continental Shelf using cruise-based observations, and compares the resulting annual productivity estimates with previously reported satellite-based estimates. Specifically, these data represent distributions of nutrients, chlorophyll, particulate organic carbon, particulate organic nitrogen, and biogenic silica that were compiled from 42 cruises (from 1967 - 2016) to the Ross Sea continental shelf to generate a comprehensive climatological dataset for November, December, January, and February. This climatology provides a novel look at broad ...
Sea Squad, 2018 Goldsmiths, University of London
Sea Squad, Liam Geary Baulch
The Sea Squad is a band of cheerleaders against climate change. Taking action as a team in formation, they gather momentum, inviting all people to cheer with them, mimicking the infinitely expandable nature of the seas' molecular structure. The work was developed and performed as a bilingual project at Est-Nord-Est in Saint-Jean-Port-Joli, Quebec, Canada, and has since been performed and exhibited internationally. The following poems are some of the chants that Sea Squad use to get a crowd cheering together against climate change.
Reconstruction Of Sea Level Around The Korean Peninsula Using Cyclostationary Empirical Orthogonal Functions, 2018 Old Dominion University
Reconstruction Of Sea Level Around The Korean Peninsula Using Cyclostationary Empirical Orthogonal Functions, Se-Hyeon Cheon, Benjamin D. Hamlington, Kyung-Duck Suh
OEAS Faculty Publications
Since the advent of the modern satellite altimeter era, the understanding of the sea level has increased dramatically. The satellite altimeter record, however, dates back only to the 1990s. The tide gauge record, on the other hand, extends through the 20th century but with poor spatial coverage when compared to the satellites. Many studies have been conducted to create a dataset with the spatial coverage of the satellite datasets and the temporal length of the tide gauge records by finding novel ways to combine the satellite data and tide gauge data in what is known as sea level reconstruction. However ...
Quantifying The Effects Of Wind Regimes And Temperature On Surface Melt Over The Antarctic Peninsula (1982–2017) Through Modeling, Remote Sensing And In-Situ Data, 2018 The Graduate Center, City University of New York
Quantifying The Effects Of Wind Regimes And Temperature On Surface Melt Over The Antarctic Peninsula (1982–2017) Through Modeling, Remote Sensing And In-Situ Data, Rajashree Datta
All Dissertations, Theses, and Capstone Projects
Surface melting over the Antarctic Peninsula (AP) plays a crucial role for the stability of ice shelves and dynamics of grounded ice, hence modulating the mass balance in a region of the world which is particularly sensitive to increasing surface temperatures. Understanding the processes that drive melting using surface energy and mass balance models is fundamental to improving estimates of current and future surface melting and associated sea level rise through ice-shelf collapse. This is even more important in view of the specific challenges presented by how circulation patterns over the topographically-complex Antarctic Peninsula, especially foehn winds, impact surface melt ...
Impacts Of Climate Extremes On Terrestrial Productivity, 2018 The Graduate Center, City University of New York
Impacts Of Climate Extremes On Terrestrial Productivity, Suhua Wei
All Dissertations, Theses, and Capstone Projects
Terrestrial biosphere absorbs approximately 28% of anthropogenic CO2 emissions. This terrestrial carbon sink might become saturated in a future climate regime. To explore the issues associated with this topic, an accurate estimate of gross primary production (GPP) of global terrestrial ecosystems is needed. A major uncertainty in modeling global terrestrial GPP is the parameter of light use efficiency (LUE). Most LUE estimates in global models are satellite-based and coarsely measured with emphasis on environmental variables. Others are from eddy covariance towers with much greater spatial and temporal data quality and emphasis on mechanistic processes, but in a limited number ...
Spatial Heterogeneity In Species Composition Constrains Plant Community Responses To Herbivory And Fertilisation, 2018 Helmholtz Institute for Functional Marine Biodiversity (HIFMB)
Spatial Heterogeneity In Species Composition Constrains Plant Community Responses To Herbivory And Fertilisation, Dorothee Hodapp, Lori A. Biederman, Philip A. Fay, Et Al.
Ecology, Evolution and Organismal Biology Publications
Environmental change can result in substantial shifts in community composition. The associated immigration and extinction events are likely constrained by the spatial distribution of species. Still, studies on environmental change typically quantify biotic responses at single spatial (time series within a single plot) or temporal (spatial beta diversity at single time points) scales, ignoring their potential interdependence. Here, we use data from a global network of grassland experiments to determine how turnover responses to two major forms of environmental change – fertilisation and herbivore loss – are affected by species pool size and spatial compositional heterogeneity. Fertilisation led to higher rates of ...
The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, 2018 The University of Western Ontario
The Periglacial Landscape Of Mars: Insight Into The 'Decameter-Scale Rimmed Depressions' In Utopia Planitia, Arya Bina
Electronic Thesis and Dissertation Repository
Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering ...
The Influence Of Arctic Amplification On Mid-Latitude Summer Circulation, 2018 Vrije Universiteit Amsterdam
The Influence Of Arctic Amplification On Mid-Latitude Summer Circulation, Dim Coumou, Giorgia Di Capua, Steve Vavrus, Lei Wang, Shih-Yu (Simon) Wang
Plants, Soils, and Climate Faculty Publications
Accelerated warming in the Arctic, as compared to the rest of the globe, might have profound impacts on mid-latitude weather. Most studies analyzing Arctic links to mid-latitude weather focused on winter, yet recent summers have seen strong reductions in sea-ice extent and snow cover, a weakened equator-to-pole thermal gradient and associated weakening of the mid-latitude circulation. We review the scientific evidence behind three leading hypotheses on the influence of Arctic changes on mid-latitude summer weather: Weakened storm tracks, shifted jet streams, and amplified quasi-stationary waves. We show that interactions between Arctic teleconnections and other remote and regional feedback processes could ...
Preventing Extinction Of At-Risk Plant Species In A Complex World, 2018 Washington University in St. Louis
Preventing Extinction Of At-Risk Plant Species In A Complex World, Holly Lee Bernardo
Arts & Sciences Electronic Theses and Dissertations
Earthճ current biodiversity crisis is now considered a true mass extinction event, with species level extinction rates well above background rates and population level extinction rates orders of magnitude more common that species extinctions. There are many threats driving this loss of biodiversity. How each threat impacts the viability of a species is highly context dependent, but all are anthropogenic in origin and so as the human population continues to increase, so too will the pressure of these threats on our natural systems. Ultimately, how much a threat decreases the viability of a species depends on how that threat influences ...
Techno-Optimism And Farmers’ Attitudes Toward Climate Change Adaptation, 2018 South Dakota State University
Techno-Optimism And Farmers’ Attitudes Toward Climate Change Adaptation, Maaz Gardezi, J. Gordon Arbuckle
In industrialized societies, techno-optimism is a belief that human ingenuity, through improved science and technology, will ultimately provide remedies to most current and future threats to human well-being, such as diseases, climate change, and poverty. Here we examine: (1) whether techno-optimism is found among Midwestern corn and soybean farmers and (2) how this confidence in human ingenuity influences their support for climate change adaptation. By examining data from a survey of nearly 5000 grain farmers in the Midwestern U.S., we found that greater techno-optimism can reduce farmers’ support for climate change adaptation and increase their propensity to express a ...
Genetic Control And Geo-Climate Adaptation Of Pod Dehiscence Provide Novel Insights Into The Soybean Domestication And Expansion, Jiaoping Zhang, Asheesh K. Singh
Loss of pod dehiscence is a key step during soybean [Glycine max (L.) Merr.] domestication. Genome-wide association analysis for soybean shattering identified loci harboring Pdh1, NST1A and SHAT1-5. Pairwise epistatic interactions were observed, and the dehiscent Pdh1 overcomes the resistance conferred by NST1A or SHAT1-5 locus, indicating that Pdh1 predominates pod dehiscence expression. Further candidate gene association analysis identified a nonsense mutation in NST1A associated with pod dehiscence. Allele composition and population differential analyses unraveled that Pdh1 and NST1A, but not SHAT1-5, underwent domestication and modern breeding selections. Geographic analysis showed that in Northeast China (NEC), indehiscence at both Pdh1 ...
Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, 2018 Boise State University
Assessment Of Snow Atmosphere Forcing During Central Idaho Atmospheric Rivers, William Rudisill
Boise State University Theses and Dissertations
Atmospheric Rivers (AR) are globally occuring weather features and the primary mechanism through which water vapor moves from the tropics and subtropics towards the mid-latitudes, doing so at rates comparable to the world’s largest terrestrial rivers. AR that encounter mountains often cause extreme precipitation in the form of rain and snow, high winds, and flooding in many watersheds. They account for as much as 20-30% of cool season precipitation in the central Idaho Mountains. In the Northern Hemisphere, seasonal snow cover during Winter and Spring months is the most variable land surface component in space and time, and acts ...
Recovering Legacy Geological Data Into A Geospatial Database Product: An Example From Baja California Norte, MéXico, Alexander C. Audet
This project develops a workflow for the extraction of legacy geological map data using a case study in the Baja California Norte, México by four workers over forty years. This project is unique from other digitization efforts worldwide because the data were already in an unregistered vector format, instead of a raster format. Thus, the methodology used in this project took advantage of this digital format by writing arcpy scripts for use inside of ArcMap, and using database feature manipulation software, in order to streamline the data extraction process, with the goal being to develop methods for dealing with ...
The Energy Yield Of Global Crops 1961-2016, 2018 University of Arkansas, Fayetteville
The Energy Yield Of Global Crops 1961-2016, Quinn Montana
Theses and Dissertations
It is often suggested that world food production must increase by 70%-100% or more by the year 2050 if we are to feed the anticipated world population at that time. To evaluate this claim, global crop production from 1961 to 2016 was inventoried using publicly available data from the United Nations Food and Agriculture Organization (FAO). To determine the adequacy of global crop output for humanity, annual global food crop production data (T y-1) were converted to energy yield in kilojoules (KJ y-1). These data were then compared to the annual metabolic energy requirement of the global human population ...
Towards The Prediction Of Climate Extremes With Attribution Analysis Through Climate Diagnostics And Modeling: Cases From Asia To North America, Boniface Opoku Fosu
All Graduate Theses and Dissertations
This project summarizes the findings of research organized in two parts. The first involved the characterization of changes in the variability of climate that lead to extreme events. The second focused on the predictability of extreme climate on time-scales ranging from short forecast lead-times to long-lead climate predictions exceeding a year.
Initial studies focused on three interrelated, yet regionally unique extreme climate phenomena. First, the relationship between increasing greenhouse gas (GHG) emissions and particulate matter (PM) concentration in basin terrain was investigated. Next, we evaluated changes in large-scale atmospheric circulation associated with two climate phenomena at either extreme side of ...