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Full-Text Articles in Atmospheric Sciences

Surviving Under The Reign Of El Niño Southern Oscillation: An Analysis Of The Effects Of Extreme El Niño Events On The Oceanographic And Biological Environment Of The Galápagos Islands, Ava Mcilvaine Apr 2020

Surviving Under The Reign Of El Niño Southern Oscillation: An Analysis Of The Effects Of Extreme El Niño Events On The Oceanographic And Biological Environment Of The Galápagos Islands, Ava Mcilvaine

Independent Study Project (ISP) Collection

El Niño Southern Oscillation (ENSO) is commonly known as the atmospheric and oceanographic powerhouse of the Southern Pacific Ocean. From phytoplankton to apex predators, ENSO controls the stability of species’ populations within this biodiverse ocean environment. El Niño’s 9-15 month alteration of the heat storage in the tropical Pacific drastically shifts the temperature, nutrient, and circulation gradient its marine life is accustomed to. A single degree change in the ocean’s surface layer temperature can have large consequences for marine species, and El Niño is commonly associated with Sea Surface Temperature Anomalies (SSTAs) between 2°- 6° Celsius. The potential danger El …


Assessing Agricultural Risk Management Using Historic Crop Insurance Loss Data Over The Ogallala Aquifer, Julian Reyes, Emile Elias, Erin M.K. Haacker, Amy Kremen, Lauren Parker, Caitlin Rottler Jan 2020

Assessing Agricultural Risk Management Using Historic Crop Insurance Loss Data Over The Ogallala Aquifer, Julian Reyes, Emile Elias, Erin M.K. Haacker, Amy Kremen, Lauren Parker, Caitlin Rottler

Department of Earth and Atmospheric Sciences: Faculty Publications

Much of the agricultural production in the Ogallala Aquifer region relies on groundwater for irrigation. In addition to declining water levels, weather and climate-driven events affect crop yields and revenues. Crop insurance serves as a risk management tool to mitigate these perils. Here, we seek to understand what long-term crop insurance loss data can tell us about agricultural risk management in the Ogallala. We assess patterns and trends in crop insurance loss data from the U.S. Department of Agriculture Risk Management Agency. Indemnities, or insurance payments, totaled $22 billion from 1989–2017 for the 161 counties that overlie the Ogallala Aquifer. …


Changes In Pm2.5 Peat Combustion Source Profiles With Atmospheric Aging In An Oxidation Flow Reactor, Judith C. Chow, Junji Cao, Lung-Wen Anthony Chen, Xiaoliang Wang, Qiyuan Wang, Jie Tian, Steven Sai Hang Ho, Adam C. Watts, Tessa B. Carlson, Steven D. Kohl, John G. Watson Oct 2019

Changes In Pm2.5 Peat Combustion Source Profiles With Atmospheric Aging In An Oxidation Flow Reactor, Judith C. Chow, Junji Cao, Lung-Wen Anthony Chen, Xiaoliang Wang, Qiyuan Wang, Jie Tian, Steven Sai Hang Ho, Adam C. Watts, Tessa B. Carlson, Steven D. Kohl, John G. Watson

Environmental & Global Health Faculty Research

Smoke from laboratory chamber burning of peat fuels from Russia, Siberia, the USA (Alaska and Florida), and Malaysia representing boreal, temperate, subtropical, and tropical regions was sampled before and after passing through a potential-aerosol-mass oxidation flow reactor (PAM-OFR) to simulate intermediately aged (∼2 d) and well-aged (∼7 d) source profiles. Species abundances in PM2.5 between aged and fresh profiles varied by several orders of magnitude with two distinguishable clusters, centered around 0.1 % for reactive and ionic species and centered around 10 % for carbon. Organic carbon (OC) accounted for 58 %–85 % of PM2.5 mass in fresh profiles with …


Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa Aug 2019

Prediction Of Wind Power Density For Electricity Generation At Makambako, Tanzania Using Auto-Regression Integrated Moving Average (Arima) Model, Josam Samson, Reuben Kainkwa

Tanzania Journal of Science

Wind speed data used in this study were from Makambako and were recorded at a height of 10 m. In the analysis, the data were extrapolated to 80 m above ground level and wind speed from July to November were found to have an average value of 17.58 m/s. November was found to be the windiest month for the whole duration while the calm month was found to be March. The wind power density was found to be highest in the month of November for the whole study duration. The months of July to November have higher wind power density …


Daily To Seasonal Moisture Signals Present In Sub-Annual Tree-Ring Data, Ian Howard May 2019

Daily To Seasonal Moisture Signals Present In Sub-Annual Tree-Ring Data, Ian Howard

Graduate Theses and Dissertations

In recent decades, there has been an increase in the development of sub-annual earlywood (EW) and latewood (LW) width tree-ring chronologies that have been used to make long-term inferences about discrete seasonal moisture variability for different regions of North America. This doctoral research developed a new network of EW, LW, and adjusted latewood (LWa) tree-ring chronologies from the western Great Plains. These chronologies were used to reconstruct 300+ years of spring and summer moisture variability over the northern and southern Plains. The reconstructions document new information about the long-term seasonal climate history of the Great Plains, including the unusual nature …


Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson May 2019

Cool And Warm Season Climate Signals In Tree Rings From North America, Max Carl Arne Torbenson

Graduate Theses and Dissertations

Earlywood (EW) and latewood (LW) ring-width chronologies have become an increasingly important proxy in paleoclimate reconstructions. These subannual variables can provide estimates of past hydroclimate variability for seasonal windows that total ring-widths cannot resolve. The strength of the relationship between EW and LW series may influence what type of paleoclimate information is embedded within the tree-ring series. High correlations (> 0.70) between EW and LW are recorded for much of the continent but the magnitude of correlation varies greatly across space and species boundaries. Using four LW chronologies from shortleaf pine, the North American conifer species displaying the lowest EW-LW …


A Long-Term (2002 To 2017) Record Of Closed-Path And Open-Path Eddy Covariance Co2 Net Ecosystem Exchange Fluxes From The Siberian Arctic, David Holl, Christian Wille, Torsten Sachs, Peter Schreiber, Benjamin R. K. Runkle, Lutz Beckebanze, Moritz Langer, Julia Boike, Eva-Maria Pfeiffer, Irina Fedorova, Dimitry Y. Bolshianov, Mikhail N. Grigoriev, Lars Kutzbach Feb 2019

A Long-Term (2002 To 2017) Record Of Closed-Path And Open-Path Eddy Covariance Co2 Net Ecosystem Exchange Fluxes From The Siberian Arctic, David Holl, Christian Wille, Torsten Sachs, Peter Schreiber, Benjamin R. K. Runkle, Lutz Beckebanze, Moritz Langer, Julia Boike, Eva-Maria Pfeiffer, Irina Fedorova, Dimitry Y. Bolshianov, Mikhail N. Grigoriev, Lars Kutzbach

Biological and Agricultural Engineering Faculty Publications and Presentations

Ground-based observations of land–atmosphere fluxes are necessary to progressively improve global climate models. Observed data can be used for model evaluation and to develop or tune process models. In arctic permafrost regions, climate–carbon feedbacks are amplified. Therefore, increased efforts to better represent these regions in global climate models have been made in recent years. We present a multi-annual time series of land–atmosphere carbon dioxide fluxes measured in situ with the eddy covariance technique in the Siberian Arctic (72◦220 N, 126◦300 E). The site is part of the international network of eddy covariance flux observation stations (FLUXNET; site ID: Ru-Sam). The …


Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr. Jan 2019

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …


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 …


Effect Of Storage Time And Temperature On Germination Ability Of Escoecaria Bussei, F Genes, Agnes Ms Nyomora May 2018

Effect Of Storage Time And Temperature On Germination Ability Of Escoecaria Bussei, F Genes, Agnes Ms Nyomora

Tanzania Journal of Science

This study was conducted in Botany Department Nursery to evaluate the effect of storage time and temperature on germinability of Excoecaria bussei.   The orthodox seeds, collected from Dodoma and Singida regions were germinated monthly from September 2013 through June 2014. Each time, seeds were soaked in water for 6 hours to soften then sown in sterile potting media. A Split-Split plot was used to compare temperature [(15°C) and (30°C)] as main plots, populations (Maktupa, Kisalu and Ilola) as Sub plots and storage time (September 2013 through June 2014) as Sub-Sub-plots on percentage seed germination.  ANOVA revealed average germination percentages of …


Advancing The Understanding Of Environmental Transformations, Bioavailability And Effects Of Nanomaterials, An International Us Environmental Protection Agency—Uk Environmental Nanoscience Initiative Joint Program, Mitch M. Lasat, Kian Fan Chung, Jamie Lead, Steve Mcgrath, Richard J. Owen, Sophie Rocks, Jason M. Unrine, Junfeng Zhang Apr 2018

Advancing The Understanding Of Environmental Transformations, Bioavailability And Effects Of Nanomaterials, An International Us Environmental Protection Agency—Uk Environmental Nanoscience Initiative Joint Program, Mitch M. Lasat, Kian Fan Chung, Jamie Lead, Steve Mcgrath, Richard J. Owen, Sophie Rocks, Jason M. Unrine, Junfeng Zhang

Plant and Soil Sciences Faculty Publications

Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United …


Construction Of A Pen-Scale Methane Collection System And Dietary Strategies For Methane Mitigation From Growing And Finishing Cattle, Thomas M. Winders Apr 2018

Construction Of A Pen-Scale Methane Collection System And Dietary Strategies For Methane Mitigation From Growing And Finishing Cattle, Thomas M. Winders

Department of Animal Science: Dissertations, Theses, and Student Research

Methane production from ruminants has been researched for many years because it has a global warming potential 25x that of carbon dioxide, meaning that mitigating smaller amounts of methane can have a large environmental impact. Research has focused on individual animal methane measurements, but the literature lack in industry-scale measurements. For that reason, the methane barn was built to evaluate dietary strategies on pens of cattle rather than on individual animals. In order to test the methane barn capabilities, an experiment designed to produce differences in methane production was conducted. Cattle received the same growing diet, at either ad-libitum access …


Outdoor Air Quality, Taylor Curley Jan 2018

Outdoor Air Quality, Taylor Curley

Global Issues in Public Health

Outdoor air quality is a significant issue for the entire world. It affects any and all people, but is more of an issue in low-income countries and among people that are more susceptible to respiratory issues such as young children, pregnant women, the elderly, and people who already suffer from respiratory problems like asthma. Poor air quality is caused by the burning of fossil fuels which releases particles and chemicals into the air like carbon dioxide, particulate matter, and nitrogen to name a few. It can cause multiple health issues such as respiratory problems to people who are exposed to …


The Clean Air Act And Its Impact On Ground Level Ozone Pollution Levels In Los Angeles, California, Rebecca Ford Jan 2018

The Clean Air Act And Its Impact On Ground Level Ozone Pollution Levels In Los Angeles, California, Rebecca Ford

Bridges: A Journal of Student Research

Ozone (O3) occurs as a photochemically produced pollutant in the troposphere and its emission and concentration is regulated by the Clean Air Act (CAA) of 1970. The Los Angeles area is an example of how O3 can be a public health hazard and taint a city’s aesthetics and quality of life through photochemical smog. This study was conducted to observe the overall effectiveness of the CAA. I explored daily O3 concentrations from 1980 to the present at three air quality monitoring stations in LA from the AirData database of the U.S. Environmental Protection Agency. National O3 standards were only exceeded …


Whole-Canopy Net Ecosystem Exchange And Water Use Efficiency In An Intermittent-Light Environment -- Dynamic Approach, Sergey Nikolayevich Kivalov Jan 2018

Whole-Canopy Net Ecosystem Exchange And Water Use Efficiency In An Intermittent-Light Environment -- Dynamic Approach, Sergey Nikolayevich Kivalov

Legacy Theses & Dissertations (2009 - 2024)

An observed 20-30% increase in forest net ecosystem exchange (NEE) on partly cloudy days is often attributed to there being more uniform canopy illumination by diffuse radiation when clouds are present. However, the sky on such days is typically populated by fair-weather cumulus clouds, bringing dynamically changing shadow-to-light conditions on the order of minutes to the forest, with radiation alternating from 1000 W m^-2 in the clear sky to less than 400 W m^-2 in under-cloud shadows. These dynamically changing conditions cannot be investigated by the conventional time-averaged eddy-covariance flux method, which requires nearly steady-state turbulent conditions over much longer …


Design Of A Small Scale Wind Generator For Low Wind Speed Areas, Ra Msuya, Rrm Kainkwa, Mi Mgwatu Dec 2017

Design Of A Small Scale Wind Generator For Low Wind Speed Areas, Ra Msuya, Rrm Kainkwa, Mi Mgwatu

Tanzania Journal of Science

Most small scale level wind turbine generators are directly driven system, variable speed, and partially connected power electronic converter system. Choice of such system is to avoid costs associated with gearbox. However, due to low wind speed in most of the tropical countries, synchronous generators with smaller or medium speed Permanent Magnet (PM) generator design found to be important and given high performance efficiency. In order to be able to harvest wind energy in off-grid population efficiently, there was a need to design a synchronous generator that can be able to operate under low wind speed, directly connected to the …


No Evidence For Trace Metal Limitation On Anaerobic Carbon Mineralization In Three Peatland Soils, Jason K. Keller, Jillian Wade Nov 2017

No Evidence For Trace Metal Limitation On Anaerobic Carbon Mineralization In Three Peatland Soils, Jason K. Keller, Jillian Wade

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store roughly one-third of the terrestrial soil carbon and release the potent greenhouse gas methane (CH4) to the atmosphere, making these wetlands among the most important ecosystems in the global carbon cycle. Despite their importance, the controls of anaerobic decomposition of organic matter to carbon dioxide (CO2) and CH4 within peatlands are not well understood. It is known, however, that the enzymes responsible for CH4 production require cobalt, iron and nickel, and there is a growing appreciation for the potential role of trace metal limitation in anaerobic decomposition. To explore the possibility of …


Variability In Methane Emissions From West Siberia's Shallow Boreal Lakes On A Regional Scale And Its Environmental Controls, Aleksandr F. Sabrekov, Benjamin R.K. Runkle, Mikhail V. Glagolev, Irina E. Terentieva, Victor M. Stephanenko, Oleg R. Kotsyurbenko, Shamil S. Maksyutov, Oleg S. Pokrovsky Aug 2017

Variability In Methane Emissions From West Siberia's Shallow Boreal Lakes On A Regional Scale And Its Environmental Controls, Aleksandr F. Sabrekov, Benjamin R.K. Runkle, Mikhail V. Glagolev, Irina E. Terentieva, Victor M. Stephanenko, Oleg R. Kotsyurbenko, Shamil S. Maksyutov, Oleg S. Pokrovsky

Biological and Agricultural Engineering Faculty Publications and Presentations

Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatiotemporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July–August 2014 within the West Siberian middle and southern taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m−2 h−1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m−2 h−1 for southern taiga lakes, respectively. …


The Mobile Monitoring Of Particulate Matter Through Wearable Sensors And Their Influence On Students' Environmental Attitudes, Joseph M. Abbate Jul 2017

The Mobile Monitoring Of Particulate Matter Through Wearable Sensors And Their Influence On Students' Environmental Attitudes, Joseph M. Abbate

DePaul Discoveries

While we have a comprehensive understanding of air pollutants, and their spatiotemporal characteristics across global, and even regional, scales, we are quite limited in our capacity to monitor neighborhood-scale emissions. The mobile monitoring of air pollution is a growing field, prospectively filling in these gaps while personalizing air quality-based tools and risk assessment. In the present study, we developed wearable sensors for particulate matter (PM); and through a citizen science approach, students of partnering Chicago schools monitored PM concentrations throughout their commutes over a five-day period. While their recorded findings would be used to explore the relationship between PM concentrations …


A Global Study Of Gpp Focusing On Light-Use Efficiency In A Random Forest Regression Model, Suhua Wei, Chuixiang Yi, Wei Fang, George Hendrey May 2017

A Global Study Of Gpp Focusing On Light-Use Efficiency In A Random Forest Regression Model, Suhua Wei, Chuixiang Yi, Wei Fang, George Hendrey

Publications and Research

Light-use efficiency (LUE) is at the core of mechanistic modeling of global gross primary production (GPP). However, 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 of sites. In this study, we conducted a comprehensive global study of tower-based LUE from 237 FLUXNET towers, and scaled up LUEs from in situ tower level to global biome level. We integrated the tower-based LUE estimates with key environmental and biological …


Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman Apr 2017

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …


Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani Apr 2017

Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani

Department of Geography: Dissertations, Theses, and Student Research

The gross primary production (GPP) metric is useful in determining trends in the terrestrial carbon cycle. Models that determine GPP utilizing the light use efficiency (LUE) approach in conjunction with biophysical parameters that account for local weather conditions and crop specific factors are beneficial in that they combine the accuracy of the biophysical model with the versatility of the LUE model. One such model developed using in situ data was adapted to operate with remote sensing derived leaf area index (LAI) data and gridded weather datasets. The model, known as the Light Use Efficiency GPP Model (EGM), uses a four …


Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman Mar 2017

Reactivity Of Ketyl And Acetyl Radicals From Direct Solar Actinic Photolysis Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The variable composition of secondary organic aerosols (SOA) contributes to the large uncertainty for predicting radiative forcing. A better understanding of the reaction mechanisms leading to aerosol formation such as for the photochemical reaction of aqueous pyruvic acid (PA) at λ ≥ 305 nm can contribute to constrain these uncertainties. Herein, the photochemistry of aqueous PA (5-300 mM) continuously sparged with air is re-examined in the laboratory under comparable irradiance at 38° N at noon on a summer day. Several analytical methods are employed to monitor the time series of the reaction, including (1) the derivatization of carbonyl (C═O) functional …


Delta‐Flux: An Eddy Covariance Network For A Climate‐Smart Lower Mississippi Basin, Benjamin R. K. Runkle, James R. Rigby, Michele L. Reba, Saseendran S. Anapalli, Joydeep Bhattacharjee, Ken W. Krauss, Lu Liang, Martin A. Locke, Kimberly A. Novick, Ruixiu Sui, Kosana Suvocarev, Paul M. White Jr. Feb 2017

Delta‐Flux: An Eddy Covariance Network For A Climate‐Smart Lower Mississippi Basin, Benjamin R. K. Runkle, James R. Rigby, Michele L. Reba, Saseendran S. Anapalli, Joydeep Bhattacharjee, Ken W. Krauss, Lu Liang, Martin A. Locke, Kimberly A. Novick, Ruixiu Sui, Kosana Suvocarev, Paul M. White Jr.

Biological and Agricultural Engineering Faculty Publications and Presentations

Networks of remotely monitored research sites are increasingly the tool used to study regional agricultural impacts on carbon and water fluxes. However, key national networks such as the National Ecological Observatory Network and AmeriFlux lack contributions from the Lower Mississippi River Basin (LMRB), a highly productive agricultural area with opportunities for soil carbon sequestration through conservation practices. The authors describe the rationale to create the new Delta‐Flux network, which will coordinate efforts to quantify carbon and water budgets at seventeen eddy covariance flux tower sites in the LMRB. The network structure will facilitate climate‐smart management strategies based on production‐scale and …


Rapid Adaptive Responses To Climate Change In Corals, Gergely Torda, Jennifer M. Donelson, Manuel Aranda, Daniel J. Barshis, Line Bay, Michael L. Berumen, David G. Bourne, Neal Cantin, Sylvain Foret, Mikhail Matz Jan 2017

Rapid Adaptive Responses To Climate Change In Corals, Gergely Torda, Jennifer M. Donelson, Manuel Aranda, Daniel J. Barshis, Line Bay, Michael L. Berumen, David G. Bourne, Neal Cantin, Sylvain Foret, Mikhail Matz

Biological Sciences Faculty Publications

Pivotal to projecting the fate of coral reefs is the capacity of reef-building corals to acclimatize and adapt to climate change. Transgenerational plasticity may enable some marine organisms to acclimatize over several generations and it has been hypothesized that epigenetic processes and microbial associations might facilitate adaptive responses. However, current evidence is equivocal and understanding of the underlying processes is limited. Here, we discuss prospects for observing transgenerational plasticity in corals and the mechanisms that could enable adaptive plasticity in the coral holobiont, including the potential role of epigenetics and coral-associated microbes. Well-designed and strictly controlled experiments are needed to …


Reducing Pollen Dispersal Using Forest Windbreaks, Carol Auer, Thomas Meyer, Vernie Sagun Jul 2016

Reducing Pollen Dispersal Using Forest Windbreaks, Carol Auer, Thomas Meyer, Vernie Sagun

Plant Science Articles

The adoption of genetically engineered (GE) crops has created a demand for practical methods to mitigate pollen dispersal and gene flow. The goal of this project was to measure the ability of a narrow forest windbreak to reduce downwind pollen fluxes from switchgrass (Panicum virgatum L.), a North American grass and model biofuels feedstock. Switchgrass fields were established in two identical plots where one had a forest windbreak and the other was in an open (control) site. Switchgrass reproduction, pollen dispersal, wind speed, and wind direction were measured over two years. Daily release of switchgrass pollen peaked at 11:00-13:30 …


Combinatory Effect Of Changing Co2, Temperature, And Long-Term Growth Temperature On Isoprene Emissions, Michael Cole Jul 2016

Combinatory Effect Of Changing Co2, Temperature, And Long-Term Growth Temperature On Isoprene Emissions, Michael Cole

DePaul Discoveries

Isoprene, the most abundant hydrocarbon in the atmosphere, plays a significant role in atmospheric chemistry. Its reactions with NOx lead to the formation of ozone in the lower troposphere, which is harmful to plants and detrimental to human health. As air temperatures and CO2 concentrations increase with climate change, it is uncertain how isoprene emissions from plants will respond. We hypothesized that isoprene emissions will increase with the combination of increasing temperature and CO­2 concentrations. We predict that oaks grown at a higher temperature will exhibit an increase in isoprene emissions with combined short-term increases in temperature …


The Correlation Between Basal Isoprene Emissions And Climate Of The Native Range Across Oak Species, Mary J. Babiez Jul 2016

The Correlation Between Basal Isoprene Emissions And Climate Of The Native Range Across Oak Species, Mary J. Babiez

DePaul Discoveries

Isoprene is a biogenic volatile organic compound that is emitted by various plant species and plays an important role in the chemistry of the atmosphere. When it reacts with pollutants in the air, such as nitrogen oxides, the precursor to ozone (O3) is formed. In this experiment, we measured leaf emissions from 20 different oak species at the Morton Arboretum (Lisle, Illinois). The aim was to better understand differences in isoprene emissions across oak species. Since emissions have been found to protect leaves against brief periods of heat stress, we hypothesized that oaks native to areas with greater …


Crop Modeling For Assessing And Mitigating The Impacts Of Extreme Climatic Events On The Us Agriculture System, Zhenong Jin Apr 2016

Crop Modeling For Assessing And Mitigating The Impacts Of Extreme Climatic Events On The Us Agriculture System, Zhenong Jin

Open Access Dissertations

The US agriculture system is the world’s largest producer of maize and soybean, and typically supplies more than one-third of their global trading. Nearly 90% of the US maize and soybean production is rainfed, thus is susceptible to climate change stressors such as heat waves and droughts. Process-based crop and cropping system models are important tools for climate change impact assessments and risk management. As data- science is becoming a new frontier for agriculture growth, the incoming decade calls for operational platforms that use hyper-local growth monitoring, high-resolution real-time weather and satellite data assimilation and cropping system modeling to help …


Upscaling Methane Emission Hotspots In Boreal Peatlands, Fabio Cresto Aleina, Benjamin R. K. Runkle, Tim Brucher, Thomas Kleinen, Victor Brovkin Mar 2016

Upscaling Methane Emission Hotspots In Boreal Peatlands, Fabio Cresto Aleina, Benjamin R. K. Runkle, Tim Brucher, Thomas Kleinen, Victor Brovkin

Biological and Agricultural Engineering Faculty Publications and Presentations

Upscaling the properties and effects of small-scale surface heterogeneities to larger scales is a challenging issue in land surface modeling. We developed a novel approach to upscale local methane emissions in a boreal peatland from the micro-topographic scale to the landscape scale. We based this new parameterization on the analysis of the water table pattern generated by the Hummock–Hollow model, a microtopography resolving model for peatland hydrology. We introduce this parameterization of methane hotspots in a global model-like version of the Hummock–Hollow model that underestimates methane emissions. We tested the robustness of the parameterization by simulating methane emissions for the …