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Articles 151 - 180 of 242

Full-Text Articles in Atmospheric Sciences

The “Stratospheric Cricket Keeper” – Developing A Simple“Life-Support” Payload For High-Altitude Balloon Missions, Lucas Kramer, Chad Serba, James Flaten Jun 2015

The “Stratospheric Cricket Keeper” – Developing A Simple“Life-Support” Payload For High-Altitude Balloon Missions, Lucas Kramer, Chad Serba, James Flaten

2017 Academic High Altitude Conference

Exposure to the environmental conditions of “near-space” (AKA the stratosphere) is quickly fatal to nearly all forms of animal life. It is even challenging to build a sealable enclosure that can keep insects (crickets) alive through the dramatic and simultaneous pressure and temperature drops experienced during a high-altitude balloon mission. This poster describes the development of a rugged “cricket keeper” in which we were able to fly crickets to the stratosphere and, quoting the words of JFK, “return (them) safely to the earth!” This “life-support” payload had large windows (for the view!) and included Arduino-logged temperature and pressure sensors, an …


Using A High Altitude Balloon Platform To Observe And Measure Seasonal Ozone Flux Over Agricultural Landscapes, Cody Sabo Jun 2015

Using A High Altitude Balloon Platform To Observe And Measure Seasonal Ozone Flux Over Agricultural Landscapes, Cody Sabo

2017 Academic High Altitude Conference

The concentration of greenhouse gasses (GHGs) in the atmosphere has continued to rise since the industrial era. This issue has had a multitude of negative impacts on all living things. Among the major GHGs are carbon dioxide, methane, nitrous oxide, and ozone. Ozone is of particular importance because it not only has the ability to trap heat in the atmosphere, but it also directly impacts organisms by causing harm to both plants and humans. The damage that ozone causes to plants is most closely linked to ozone uptake rather than ozone concentration. So, measuring ozone uptake is becoming critical for …


Numerical Model Derived Altimeter Correction Maps For Non-Standard Atmospheric Temperature And Pressure, Thomas A. Guinn, Frederick R. Mosher Apr 2015

Numerical Model Derived Altimeter Correction Maps For Non-Standard Atmospheric Temperature And Pressure, Thomas A. Guinn, Frederick R. Mosher

International Journal of Aviation, Aeronautics, and Aerospace

Altimeter corrections for non-standard temperature pose a challenge because accurate calculations require detailed knowledge of the temperature structure of the atmosphere between the surface and the aircraft. By applying basic hypsometric formulae to high resolution numerical model temperature and moisture output, detailed maps of current and forecasted corrected D-values are created. Corrected D-values provide the altitude difference between the true altitude and the indicated altitude from a pressure altimeter. Unlike standard D-values, the corrected D-value corrects for non-standard pressure in addition to non-standard temperature and is therefore useful for flights below class A airspace. Maps of corrected D-value may help …


Comparing Different Methods For Estimating Total Open Heliospheric Magnetic Flux, Samantha J. Wallace Apr 2015

Comparing Different Methods For Estimating Total Open Heliospheric Magnetic Flux, Samantha J. Wallace

Doctoral Dissertations and Master's Theses

There are extended periods over the solar cycle where significant discrepancies occur between the observed open magnetic flux (i.e., those based on spacecraft observations) and that determined from coronal models. One explanation for the source of these discrepancies is the magnetic fields in CMEs, which have yet to magnetically disconnect from the Sun. These “closed” flux sources can be included in open flux estimates, because open and closed magnetic field lines are not easily distinguished in spacecraft data. Another possibility is that a portion of the open flux measured by in situ spacecraft originates from the time-dependent evolution of solar …


Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D. Mar 2015

Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

Knowledge of standard air temperature, pressure, density, speed of sound, and viscosity as a function of altitude is essential information in aircraft design, performance testing, pressure altimeter calibration, and several other aeronautical engineering and aviation science applications. A new efficient computational method for rapid calculations of standard atmospheric parameters up to 86 orthometric km is presented. Additionally, mass and weight of each standard atmospheric layer were calculated using a numerical integration method. The sum of all fractional masses and weights represents the total mass and weight of Earth’s atmosphere. The results obtained here agree well with measurements and models of …


A Novel Approach For Identifying Cloud Clusters Developing Into Tropical Cyclones, Chaunte' W. Lacewell Jan 2015

A Novel Approach For Identifying Cloud Clusters Developing Into Tropical Cyclones, Chaunte' W. Lacewell

Dissertations

Providing advance notice of rare events, such as a cloud cluster (CC) developing into a tropical cyclone (TC), is of great importance. Having advance warning of such rare events possibly can help avoid or reduce the risk of damages and allow emergency responders and the affected community enough time to respond appropriately. Considering this, forecasters need better data mining and data driven techniques to identify developing CCs. Prior studies have attempted to predict the formation of TCs using numerical weather prediction models as well as satellite and radar data. However, refined observational data and forecasting techniques are not always available …


Reply To ‘Co2 Emissions From Crop Residue-Derived Biofuels’, Adam Liska, Haishun Yang, Matthew P. Pelton, Andrew E. Suyker Oct 2014

Reply To ‘Co2 Emissions From Crop Residue-Derived Biofuels’, Adam Liska, Haishun Yang, Matthew P. Pelton, Andrew E. Suyker

Adam Liska Papers

The soil organic carbon (SOC) model that we used was parameterized with data from arable land under normal farming conditions in North America, Europe, Africa and Asia, but the equation is insensitive to changes in tillage, soil texture and moisture. The model has reasonable accuracy, however, in predicting changes in SOC, residue remaining and CO2 emissions from initial SOC, carbon inputs from residue, and daily temperature; the shoot-to-root ratio used in the geospatial simulation was 0.29 (that is, root carbon is 29% of total aboveground carbon), which did not underestimate carbon input to soil (Supplementary Figure 2 in Ref. …


Interactive Comment On “Iodine Oxide In The Global Marine Boundary Layer” By C. Prados-Roman Et Al., Marcelo I. Guzman Oct 2014

Interactive Comment On “Iodine Oxide In The Global Marine Boundary Layer” By C. Prados-Roman Et Al., Marcelo I. Guzman

Chemistry Faculty Publications

No abstract provided.


Aerodynamic Study Of Forces Due To Wind Velocity And Angle Of Attack On Parabolic Solar Troughs, Brian Northshield Jul 2014

Aerodynamic Study Of Forces Due To Wind Velocity And Angle Of Attack On Parabolic Solar Troughs, Brian Northshield

Doctoral Dissertations and Master's Theses

Scant literature exists of the atmospheric effects on parabolic solar troughs. The technology is relatively new, so supporting studies by consequence are as well.

This study examines the effects of wind at various speeds, with various angles of attack on parabolic solar troughs. This begins by picking up on previous study, corroborating previously found data, then introduces new angles of attack. The model includes the presence of the solar tube where other studies omit.

The purpose of this study is to build a data set which is useful for structural consideration. During the course of this study, it was found …


Probability Distributions And Threshold Selection For Monte Carlo–Type Tropical Cyclone Wind Speed Forecasts, Steven M. Lazarus, Michael E. Splitt, Sarah Collins, Denis N. Botambekov, William P. Roeder Apr 2014

Probability Distributions And Threshold Selection For Monte Carlo–Type Tropical Cyclone Wind Speed Forecasts, Steven M. Lazarus, Michael E. Splitt, Sarah Collins, Denis N. Botambekov, William P. Roeder

Aeronautics Faculty Publications

Probabilistic wind speed forecasts for tropical cyclones from Monte Carlo–type simulations are assessed within a theoretical framework for a simple unbiased Gaussian system that is based on feature size and location error that mimic tropical cyclone wind fields. Aspects of the wind speed probability data distribution, including maximumexpected probability and forecast skill, are assessed. Wind speed probability distributions are shown to be well approximated by a bounded power-law distribution when the feature size is smaller than the location error and tends toward a U-shaped distribution as the location error becomes small. Forecast skill (i.e., true and Heidke skill scores) is …


Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang Apr 2014

Effects Of Stratospheric Ozone Recovery On Photochemistry And Ozone Air Quality In The Troposphere, H. Zhang, Shiliang Wu, Y. Huang, Y. Wang

Michigan Tech Publications, Part 1

There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor …


Modeling The Thermosphere As A Driven-Dissipative Thermodynamic System, William R. Frey, C. S. Lin, Matthew B. Garvin, Ariel O. Acebal Apr 2014

Modeling The Thermosphere As A Driven-Dissipative Thermodynamic System, William R. Frey, C. S. Lin, Matthew B. Garvin, Ariel O. Acebal

Faculty Publications

Thermospheric density impacts satellite position and lifetime through atmospheric drag. More accurate specification of thermospheric temperature, a key input to current models such as the High Accuracy Satellite Drag Model, can decrease model density errors. This paper improves the model of Burke et al. (2009) to model thermospheric temperatures using the magnetospheric convective electric field as a driver. In better alignment with Air Force satellite tracking operations, we model the arithmetic mean temperature, T 1/2, defined by the Jacchia (1977) model as the mean of the daytime maximum and nighttime minimum exospheric temperatures occurring in opposite hemispheres at a …


Uncertainties In Life Cycle Greenhouse Gas Emissions From U.S. Beef Cattle, Quentin M. Dudley, Adam Liska, Andrea K. Watson, Galen E. Erickson Apr 2014

Uncertainties In Life Cycle Greenhouse Gas Emissions From U.S. Beef Cattle, Quentin M. Dudley, Adam Liska, Andrea K. Watson, Galen E. Erickson

Adam Liska Papers

Beef cattle feedlots are estimated to contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy could target reducing these emissions. Life cycle assessment (LCA) of GHG emissions from U.S. grain-fed beef cattle was conducted based on industry statistics and previous studies to identify the main sources of uncertainty in these estimations. Uncertainty associated with GHG emissions from indirect land use change, pasture soil emissions (e.g. soil carbon sequestration), enteric fermentation from cattle on pasture, and methane emissions from feedlot manure, respectively, contributed the most variability to life cycle GHG emissions from beef production. Feeding of …


Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu Jan 2014

Landsat-8: Science And Product Vision For Terrestrial Global Change Research, David P. Roy, M. A. Wulder, T. R. Loveland, C. E. Woodcock, R. G. Allen, M. C. Anderson, D. Helder, J. R. Irons, D. M. Johnson, R. Kennedy, T. A. Scambos, C. B. Schaaf, J. R. Schott, Y. Sheng, E. F. Vermote, A. S. Belward, R. Bindschadler, W. B. Cohen, F. Gao, J. D. Hipple, P. Hostert, Desert Research Institute, Reno, Nv, C. O. Justice, Ayse Kilic, V. Kovalskyy, Z. P. Lee, L. Lymburner, J. G. Masek, J. Mccorkel, Y. Shuai, R. Trezza, J. Vogelmann, R. H. Wynne, Z. Zhu

School of Natural Resources: Faculty Publications

Landsat 8, a NASA and USGS collaboration, acquires global moderate-resolution measurements of the Earth's terrestrial and polar regions in the visible, near-infrared, short wave, and thermal infrared. Landsat 8 extends the remarkable 40 year Landsat record and has enhanced capabilities including new spectral bands in the blue and cirrus cloud-detection portion of the spectrum, two thermal bands, improved sensor signal-to-noise performance and associated improvements in radiometric resolution, and an improved duty cycle that allows collection of a significantly greater number of images per day. This paper introduces the current (2012–2017) Landsat Science Team's efforts to establish an initial understanding of …


Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton Jan 2014

Estimation Of Crop Gross Primary Production (Gpp): FaparChl Versus Mod15a2 Fpar, Qingyuan Zhang, Yen-Ben Cheng, A. I. Lyapustin, Yujie Wang, Feng Gao, Andrew E. Suyker, Shashi B. Verma, Elizabeth M. Middleton

School of Natural Resources: Faculty Publications

Photosynthesis (PSN) is a pigment level process in which antenna pigments (predominately chlorophylls) in chloroplasts absorb photosynthetically active radiation (PAR) for the photochemical process. PAR absorbed by foliar non-photosynthetic components is not used for PSN. The fraction of PAR absorbed (fAPAR) by a canopy/vegetation (i.e., fAPARcanopy) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) images, referred to as MOD15A2 FPAR, has been used to compute absorbed PAR (APAR) for PSN (APARPSN) which is utilized to produce the standard MODIS gross primary production (GPP) product, referred to as MOD17A2 GPP. In this study, the fraction of PAR …


Morphology And Mixing State Of Atmospheric Particles: Links To Optical Properties And Cloud Processing, Swarup China Jan 2014

Morphology And Mixing State Of Atmospheric Particles: Links To Optical Properties And Cloud Processing, Swarup China

Dissertations, Master's Theses and Master's Reports - Open

Atmospheric particles are ubiquitous in Earth’s atmosphere and impact the environment and the climate while affecting human health and Earth’s radiation balance, and degrading visibility. Atmospheric particles directly affect our planet’s radiation budget by scattering and absorbing solar radiation, and indirectly by interacting with clouds. Single particle morphology (shape, size and internal structure) and mixing state (coating by organic and inorganic material) can significantly influence the particle optical properties as well as various microphysical processes, involving cloud-particle interactions and including heterogeneous ice nucleation and water uptake. Conversely, aerosol cloud processing can affect the morphology and mixing of the particles. For …


Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation, Mohamed E. Hanafy Jan 2014

Characterization Of The Atmospheric Effects On The Transmission Of Thermal Radiation, Mohamed E. Hanafy

Dissertations, Master's Theses and Master's Reports - Open

Atmospheric scattering plays a crucial rule in degrading the performance of electro optical imaging systems operating in the visible and infra-red spectral bands, and hence limits the quality of the acquired images, either through reduction of contrast or increase of image blur. The exact nature of light scattering by atmospheric media is highly complex and depends on the types, orientations, sizes and distributions of particles constituting these media, as well as wavelengths, polarization states and directions of the propagating radiation. Here we follow the common approach for solving imaging and propagation problems by treating the propagating light through atmospheric media …


Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray Jan 2014

Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray

Dissertations, Master's Theses and Master's Reports - Open

This work presents a 1-D process scale model used to investigate the chemical dynamics and temporal variability of nitrogen oxides (NOx) and ozone (O3) within and above snowpack at Summit, Greenland for March-May 2009 and estimates surface exchange of NOx between the snowpack and surface layer in April-May 2009. The model assumes the surface of snowflakes have a Liquid Like Layer (LLL) where aqueous chemistry occurs and interacts with the interstitial air of the snowpack. Model parameters and initialization are physically and chemically representative of snowpack at Summit, Greenland and model results are compared to …


Enhancing Ground Based Telescope Performance With Image Processing, John C. Zingarelli Nov 2013

Enhancing Ground Based Telescope Performance With Image Processing, John C. Zingarelli

Theses and Dissertations

The Space Surveillance Telescope (SST) is a Defense Advanced Research Projects Agency (DARPA) program designed to detect objects in space like Near Earth Asteroids (NEAs) and space debris in the Geosynchronous Earth Orbit (GEO) belt. Binary hypothesis tests (BHTs) have historically been used to facilitate the detection of new objects in space. In this dissertation, a multi-hypothesis test (MHT) detection strategy is introduced to improve the detection performance of the SST. In this context, the MHT determines if an unresolvable point source is in the center, corner or side of a pixel in contrast to a BHT, which only tests …


Quantifying Risks Of Climate Change And Sea Level Rise To Naval Station Norfolk (Serdp Rc-1701), Kelly Burks-Copes Oct 2013

Quantifying Risks Of Climate Change And Sea Level Rise To Naval Station Norfolk (Serdp Rc-1701), Kelly Burks-Copes

October 2, 2013: Quantifying Risks and Moving Forward

No abstract provided.


Characterization Of Secondary Organic Aerosol Precursors Using Two-Dimensional Gas Chromatography With Time Of Flight Mass Spectrometry (Gc×Gc/Tofms), Melissa Jordan Roskamp Sep 2013

Characterization Of Secondary Organic Aerosol Precursors Using Two-Dimensional Gas Chromatography With Time Of Flight Mass Spectrometry (Gc×Gc/Tofms), Melissa Jordan Roskamp

Dissertations and Theses

The oxidation of volatile organic compounds (VOCs) plays a role in both regional and global air quality through the formation of secondary organic aerosols (SOA). More than 1000TgC/yr of non-methane VOCs are emitted from biogenic sources (significantly greater than from anthropogenic sources). Despite this magnitude and potential importance for air quality, the body of knowledge around the identities, quantities and oxidation processes of these compounds is still incomplete (e.g., Goldstein & Galbally, 2007; Robinson et al., 2009). Two-dimensional gas chromatography paired with time-of-flight mass spectrometry (GC×GC/TOFMS) is a powerful analytical technique which is explored here for its role in better …


Incorporating Chemical Activity And Relative Humidity Effects In Regional Air Quality Modeling Of Organic Aerosol Formation, Marguerite Colasurdo Marks Aug 2013

Incorporating Chemical Activity And Relative Humidity Effects In Regional Air Quality Modeling Of Organic Aerosol Formation, Marguerite Colasurdo Marks

Dissertations and Theses

Atmospheric particulate matter is known to have significant effects on human health, visibility, and global climate. The magnitudes of these effects, however, depend in complex ways on chemical composition, relative humidity, temperature, phase state, and other parameters. Current regional air quality models such as CMAQ (Community Multiscale Air Quality model) ignore many of these considerations, and consider that the formation of secondary organic aerosol (SOA) can be calculated by assuming thermodynamic ideality in the organic particulate matter (OPM) phase as well as negligible uptake of water into the OPM phase. Theoretical predictions and model simulations considering non-ideality and water uptake …


Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto Aug 2013

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR Program Research Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In the future, multivariable spatial correlations …


Improving Multiple Surface Range Estimation Of A 3-Dimensional Flash Ladar In The Presence Of Atmospheric Turbulence, Brian J. Neff Jun 2013

Improving Multiple Surface Range Estimation Of A 3-Dimensional Flash Ladar In The Presence Of Atmospheric Turbulence, Brian J. Neff

Theses and Dissertations

Laser Radar sensors can be designed to provide two-dimensional and three-dimensional (3-D) images of a scene from a single laser pulse. Currently, there are various data recording and presentation techniques being developed for 3-D sensors. While the technology is still being proven, many applications are being explored and suggested. As technological advancements are coupled with enhanced signal processing algorithms, it is possible that this technology will present exciting new military capabilities for sensor users. The goal of this work is to develop an algorithm to enhance the utility of 3-D Laser Radar sensors through accurate ranging to multiple surfaces per …


Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan Jan 2013

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O3), and nitrate radical (NO3), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …


Tropical Cyclone Intensity Estimation Using Temporal And Spatial Features From Satellite Data, Gholamreza Fetanat Haghighi Jan 2013

Tropical Cyclone Intensity Estimation Using Temporal And Spatial Features From Satellite Data, Gholamreza Fetanat Haghighi

Dissertations

Accurate intensity estimation of tropical cyclones (TC) is an important topic of research due to its economic impact and public safety concerns. An accurate measure of the current wind strength is necessary to accurately predict TC intensity. We have developed and tested automated method to estimate TC intensity based on the existing historical satellite images alone. The Hurricane Satellite data (HURSAT-B1) is used to develop the algorithm, which focuses on the North Atlantic from 1978-2009. The algorithm is trained and validated using aircraft reconnaissance-based data. Here, the data is restricted to include only fixes that are over water and are …


Chemical Consequences Of Chicxulub Impact Ejecta Reentry, Devon Donald Parkos Jan 2013

Chemical Consequences Of Chicxulub Impact Ejecta Reentry, Devon Donald Parkos

Open Access Theses

The Chicxulub impact 66.0 million years ago initiated the second biggest extinction in the Phanerozoic Eon. The global reentry of material ejected by the impact generated a strong pulse of thermal radiation that wiped out much of the terrestrial biota. The cause of the marine extinction, however, has remained elusive. This report shows that reentering ejecta produces enough NOx to acidify the upper ocean and cause a massive marine extinction. Using non-equilibrium chemically reacting flow simulations coupled with atmospheric transport modeling, it is determined that enough NOx reached the stratosphere and precipitated to overpower the carbonate buffer and acidify the …


Analyzing Experimental Data And Model Parameters: Implications For Predictions Of Soa Using Chemical Transport Models, Kelley Barsanti, Annmarie G. Carlton, Serena H. Chung Jan 2013

Analyzing Experimental Data And Model Parameters: Implications For Predictions Of Soa Using Chemical Transport Models, Kelley Barsanti, Annmarie G. Carlton, Serena H. Chung

Civil and Environmental Engineering Faculty Publications and Presentations

Despite critical importance for air quality and climate predictions, accurate representation of secondary organic aerosol (SOA) formation remains elusive. An essential addition to the ongoing discussion of improving model predictions is an acknowledgement of the linkages between experimental conditions, parameter optimization and model output, as well as the linkage between empirically-derived partitioning parameters and the physicochemical properties of SOA they represent in models. In this work, a "best available" set of SOA modeling parameters is selected by comparing predicted SOA yields and mass concentrations with observed yields and mass concentrations from a comprehensive list of published smog chamber studies. Evaluated …


Terpene And Terpenoid Emissions And Secondary Organic Aerosol Production, Rosa M. Flores Jan 2013

Terpene And Terpenoid Emissions And Secondary Organic Aerosol Production, Rosa M. Flores

Dissertations, Master's Theses and Master's Reports - Open

Approximately 90% of fine aerosol in the Midwestern United States has a regional component with a sizable fraction attributed to secondary production of organic aerosol (SOA). The Ozark Forest is an important source of biogenic SOA precursors like isoprene (> 150 mg m-2 d-1), monoterpenes (10-40 mg m-2 d-1), and sesquiterpenes (10-40 mg m-2d-1). Anthropogenic sources include secondary sulfate and nitrate and biomass burning (51-60%), vehicle emissions (17-26%), and industrial emissions (16-18%). Vehicle emissions are an important source of volatile and vapor-phase, semivolatile aliphatic and aromatic hydrocarbons that are important …


Life Cycle Boundaries And Greenhouse Gas Emissions From Beef Cattle, Quentin M. Dudley Jul 2012

Life Cycle Boundaries And Greenhouse Gas Emissions From Beef Cattle, Quentin M. Dudley

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Beef cattle are estimated to directly contribute 26% of U.S. agricultural greenhouse gas (GHG) emissions, and future climate change policy may target reducing these emissions. Life cycle assessment (LCA) of GHG emissions from U.S. feedlot beef cattle was conducted to compare methods of the U.S. Environmental Protection Agency (EPA) with a more complete evaluation of emissions. The inclusion of emissions from crop production for feed, associated land use change, and other minor factors nearly doubled GHG emissions associated with beef feedlots from the EPA Annual Inventory estimate of 1611 kgCO2e hd-1 yr-1 to 3182 ± 167 …