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Civil and Environmental Engineering Faculty Publications and Presentations

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Full-Text Articles in Physical Sciences and Mathematics

Warming Of The Willamette River, 1850–Present: The Effects Of Climate Change And Direct Human Interventions, Stefan Talke, David Jay, Heida Diefenderfer Sep 2022

Warming Of The Willamette River, 1850–Present: The Effects Of Climate Change And Direct Human Interventions, Stefan Talke, David Jay, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Using archival research methods, we found and combined data from multiple sources to produce a unique, 140 year record of daily water temperature (Tw) in the lower Willamette River, Oregon (1881–1890, 1941–present). Additional daily weather and river flow records from the 1850s onwards are used to develop and validate a statistical regression model of Tw for 1850–2020. The model simulates the time-lagged response of Tw to air temperature and river flow, and is calibrated for three distinct time periods: the late 19th, mid 20th, and early 21st centuries. Results show that Tw has trended upwards at ~1.1 °C …


Storm Tide Amplification And Habitat Changes Due To Urbanization Of A Lagoonal Estuary, Philip Orton, Eric W. Sanderson, Stefan Talke, Mario Giampieri, Kytt Macmanus Jan 2020

Storm Tide Amplification And Habitat Changes Due To Urbanization Of A Lagoonal Estuary, Philip Orton, Eric W. Sanderson, Stefan Talke, Mario Giampieri, Kytt Macmanus

Civil and Environmental Engineering Faculty Publications and Presentations

In recent centuries, human activities have greatly modified the geomorphology of coastal regions. However, studies of historical and possible future changes in coastal flood extremes typically ignore the influence of geomorphic change. Here, we quantify the influence of 20th-century man-made changes to Jamaica Bay, New York City, on present-day storm tides. We develop and validate a hydrodynamic model for the 1870s based on detailed maps of bathymetry, seabed characteristics, topography, and tide observations for use alongside a present-day model. Predominantly through dredging, landfill, and inlet stabilization, the average water depth of the bay increased from 1.7 to 4.5 m, tidal …


Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle Mar 2019

Remote Sensing Of Water Use Efficiency And Terrestrial Drought Recovery Across The Contiguous United States, Behzad Ahmadi, Ali Ahmadalipour, Glenn Tootle

Civil and Environmental Engineering Faculty Publications and Presentations

Ecosystem water-use efficiency (WUE) is defined as the ratio of carbon gain (i.e., gross primary productivity; GPP) to water consumption (i.e., evapotranspiration; ET). WUE is markedly influential on carbon and water cycles, both of which are fundamental for ecosystem state, climate and the environment. Drought can affect WUE, subsequently disturbing the composition and functionality of terrestrial ecosystems. In this study, the impacts of drought on WUE and its components (i.e., GPP and ET) are assessed across the Contiguous US (CONUS) at fine spatial and temporal resolutions. Soil moisture simulations from land surface modeling are utilized to detect and characterize agricultural …


Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth Jan 2019

Mechanics And Historical Evolution Of Sea Level Blowouts In New York Harbor, Praneeth Gurumurthy, Philip Orton, Stefan A. Talke, Nickitas Georgas, James F. Booth

Civil and Environmental Engineering Faculty Publications and Presentations

Wind-induced sea level blowouts, measured as negative storm surge or extreme low water (ELW), produce public safety hazards and impose economic costs (e.g., to shipping). In this paper, we use a regional hydrodynamic numerical model to test the effect of historical environmental change and the time scale, direction, and magnitude of wind forcing on negative and positive surge events in the New York Harbor (NYH). Environmental sensitivity experiments show that dredging of shipping channels is an important factor affecting blowouts while changing ice cover and removal of other roughness elements are unimportant in NYH. Continuously measured water level records since …


Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield Jan 2019

Bigger Tides, Less Flooding: Effects Of Dredging On Barotropic Dynamics In A Highly Modified Estuary, David K. Ralston, Stefan Talke, W. Rockwell Geyer, Hussein A. M. Al-Zubaidi, Christopher K. Sommerfield

Civil and Environmental Engineering Faculty Publications and Presentations

Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the …


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 …


Decision Support System For The Design And Planning Of Low-Impact Development Practices: The Case Of Seoul, Jae-Yeol Song, Eun-Sung Chung, Soo Hyun Kim Feb 2018

Decision Support System For The Design And Planning Of Low-Impact Development Practices: The Case Of Seoul, Jae-Yeol Song, Eun-Sung Chung, Soo Hyun Kim

Civil and Environmental Engineering Faculty Publications and Presentations

This study presented the conceptual framework of the water-management analysis module (WMAM) to derive effective physical specifications for the design and planning of low-impact development (LID) practices using the storm-water management model (SWMM). This decision-support system can be used for six LID types and has the following key capabilities: determining relevant LID design parameters within the SWMM that critically influence the hydrological cycle components using a simple sensitivity analysis and determining the best hydrological values for LID planning specification. This study analyzed a highly urbanized university campus as a case study to determine the design and planning specifications for an …


Apprehensive Drought Characteristics Over Iraq: Results Of A Multidecadal Spatiotemporal Assessment, Maysoun Ayad Hameed, Ali Ahmadalipour, Hamid Moradkhani Feb 2018

Apprehensive Drought Characteristics Over Iraq: Results Of A Multidecadal Spatiotemporal Assessment, Maysoun Ayad Hameed, Ali Ahmadalipour, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Drought is an extreme climate phenomenon that happens slowly and periodically threatens the environmental and socio-economic sectors. Iraq is one of the countries in the Middle East that has been dealing with serious drought-related issues in the 21st century. Here, we investigate meteorological drought across Iraq from 1948 to 2009 at 0.25° spatial resolution. The Standardized Precipitation Evapotranspiration Index (SPEI) has been utilized as a multi-scalar drought index accounting for the effects of temperature variability on drought. Four of the main characteristics of drought including extent, intensity, frequency and duration are studied and the associated spatiotemporal patterns are investigated for …


Time Varying Parameter Models For Catchments With Land Use Change: The Importance Of Model Structure, Sahani Pathiraja, Daniela Anghileri, Paolo Burlando, Ashish Sharma, Lucy Marshall, Hamid Moradkhani Jul 2017

Time Varying Parameter Models For Catchments With Land Use Change: The Importance Of Model Structure, Sahani Pathiraja, Daniela Anghileri, Paolo Burlando, Ashish Sharma, Lucy Marshall, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Rapid population and economic growth in South-East-Asia has been accompanied by extensive land use change with consequent impacts on catchment hydrology. Modelling methodologies capable of handling changing land use conditions are therefore becoming ever more important, and are receiving increasing attention from hydrologists. A recently developed Data Assimilation based framework that allows model parameters to vary through time in response to signals of change in observations is considered for a medium sized catchment (2880 km²) in Northern Vietnam experiencing substantial but gradual land cover change. We investigate the efficacy of the method as well as the importance of the chosen …


Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray May 2017

Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal …


Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup Apr 2017

Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based …


Mass Exchange Dynamics Of Surface And Subsurface Oil In Shallow-Water Transport, Saeed Moghimi, Jorge Ramirez, Juan M. Restrepo, Shankar Venkataramani Mar 2017

Mass Exchange Dynamics Of Surface And Subsurface Oil In Shallow-Water Transport, Saeed Moghimi, Jorge Ramirez, Juan M. Restrepo, Shankar Venkataramani

Civil and Environmental Engineering Faculty Publications and Presentations

We formulate a model for the mass exchange between oil at and below the sea surface. This is a particularly important aspect of modeling oil spills. Surface and subsurface oil have different chemical and transport characteristics and lumping them together would compromise the accuracy of the resulting model. Without observational or computational constraints, it is thus not possible to quantitatively predict oil spills based upon partial field observations of surface and/or sub-surface oil. The primary challenge in capturing the mass exchange is that the principal mechanisms are on the microscale. This is a serious barrier to developing practical models for …


Using Satellite Observations To Characterize The Response Of Estuarine Turbidity Maxima To External Forcing, Austin S. Hudson, Stefan A. Talke, David A. Jay Mar 2017

Using Satellite Observations To Characterize The Response Of Estuarine Turbidity Maxima To External Forcing, Austin S. Hudson, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This study explores the spatial and temporal character of turbidity maxima in the Columbia River Estuary (CRE) using satellite observations. Surface reflectance data measured by the Moderate Imaging Spectroradiometer (MODIS) were calibrated against in situ measurements of surface turbidity (R2 = 0.85 for 205 measurements). More than 1500 satellite images from 2000 to 2015 were then conditionally sampled to explore the physical processes that drive the spatial distribution of the turbidity field. We find satellite measurements are able to describe seasonal, spring–neap, and spatial features of the estuarine turbidity maxima (ETM) that are not easily observable by other means. System-wide …


Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer Sep 2016

Tidal-Fluvial And Estuarine Processes In The Lower Columbia River: Ii. Water Level Models, Floodplain Wetland Inundation, And System Zones, David A. Jay, Amy B. Borde, Heida Diefenderfer

Civil and Environmental Engineering Faculty Publications and Presentations

Spatially varying water-level regimes are a factor controlling estuarine and tidal-fluvial wetland vegetation patterns. As described in Part I, water levels in the Lower Columbia River and estuary (LCRE) are influenced by tides, river flow, hydropower operations, and coastal processes. In Part II, regression models based on tidal theory are used to quantify the role of these processes in determining water levels in the mainstem river and floodplain wetlands, and to provide 21-year inundation hindcasts. Analyses are conducted at 19 LCRE mainstem channel stations and 23 tidally exposed floodplain wetland stations. Sum exceedance values (SEVs) are used to compare wetland …


Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce Jul 2016

Multiple New-Particle Growth Pathways Observed At The Us Doe Southern Great Plains Field Site, Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. Mcmurry, James N. Smith, Jeffery R. Pierce

Civil and Environmental Engineering Faculty Publications and Presentations

New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low volatility species, from diameters ∼ 1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids …


A Novel Methodology For Spatial Damage Detection And Imaging Using A Distributed Carbon Nanotube-Based Composite Sensor Combined With Electrical Impedance Tomography, Hongbo Dai, Gerard J. Gallo, Thomas Schumacher, Erik T. Thostenson Mar 2016

A Novel Methodology For Spatial Damage Detection And Imaging Using A Distributed Carbon Nanotube-Based Composite Sensor Combined With Electrical Impedance Tomography, Hongbo Dai, Gerard J. Gallo, Thomas Schumacher, Erik T. Thostenson

Civil and Environmental Engineering Faculty Publications and Presentations

This paper describes a novel non-destructive evaluation methodology for imaging of damage in composite materials using the electrical impedance tomography (EIT) technique applied to a distributed carbon nanotube-based sensor. The sensor consists of a nonwoven aramid fabric, which was first coated with nanotubes using a solution casting approach and then infused with epoxy resin through the vacuum assisted resin transfer molding technique. Finally, this composite sensor is cured to become a mechanically-robust, electromechanically-sensitive, and highly customizable distributed two-dimensional sensor which can be adhered to virtually any substrate. By assuming that damage on the sensor directly affects its conductivity, a difference …


Nonstationary Internal Tides Observed Using Dual-Satellite Altimetry, Edward D. Zaron Sep 2015

Nonstationary Internal Tides Observed Using Dual-Satellite Altimetry, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

Dual-satellite crossover data from the Jason-2 and Cryosat-2 altimeter missions are used in a novel approach to quantify stationary and nonstationary tides from time-lagged mean square sea surface height (SSH) differences, computed for lags from 1 to 1440 h (60 days). The approach is made feasible by removing independent estimates of the stationary tide and mesoscale SSH variance, which greatly reduces the sampling error of the SSH statistics. For the semidiurnal tidal band, the stationary tidal variance is approximately 0.73 cm(2), and the nonstationary variance is about 0.33 cm(2), or 30% of the total. The temporal correlation of the nonstationary …


The Effects Of Global Change Upon United States Air Quality, Rodrigo Gonzalez-Abraham, Serena H. Chung, Jeremy C. Avise, Brian Lamb, Eric P. Salathé Jr., Christopher G. Nolte, Dan Loughlin, Alex Guenther, Christine Wiedinmyer, Tiffany Duhl, Yang Zhang, David G. Streets Jan 2015

The Effects Of Global Change Upon United States Air Quality, Rodrigo Gonzalez-Abraham, Serena H. Chung, Jeremy C. Avise, Brian Lamb, Eric P. Salathé Jr., Christopher G. Nolte, Dan Loughlin, Alex Guenther, Christine Wiedinmyer, Tiffany Duhl, Yang Zhang, David G. Streets

Civil and Environmental Engineering Faculty Publications and Presentations

To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the United States (US), we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We …


Secondary Organic Aerosol Formation And Organic Nitrate Yield From No3 Oxidation Of Biogenic Hydrocarbons, Juliane L. Fry, Danielle C. Draper, Kelley C. Barsanti, James N. Smith, John Ortega, Paul M. Winkler, Michael J. Lawler, Steven S. Brown, Peter M. Edwards, Ronald C. Cohen, Lance Lee Sep 2014

Secondary Organic Aerosol Formation And Organic Nitrate Yield From No3 Oxidation Of Biogenic Hydrocarbons, Juliane L. Fry, Danielle C. Draper, Kelley C. Barsanti, James N. Smith, John Ortega, Paul M. Winkler, Michael J. Lawler, Steven S. Brown, Peter M. Edwards, Ronald C. Cohen, Lance Lee

Civil and Environmental Engineering Faculty Publications and Presentations

The secondary organic aerosol (SOA) mass yields from NO3 oxidation of a series of biogenic volatile organic compounds (BVOCs), consisting of five monoterpenes and one sesquiterpene (α-pinene, β-pinene, Δ-3-carene, limonene, sabinene, and β-caryophyllene), were investigated in a series of continuous flow experiments in a 10 m3 indoor Teflon chamber. By making in situ measurements of the nitrate radical and employing a kinetics box model, we generate time-dependent yield curves as a function of reacted BVOC. SOA yields varied dramatically among the different BVOCs, from zero for α-pinene to 38−65% for Δ-3-carene and 86% for β-caryophyllene at mass loading of 10 …


Toward A Reliable Prediction Of Seasonal Forecast Uncertainty: Addressing Model And Initial Condition Uncertainty With Ensemble Data Assimilation And Sequential Bayesian Combination, Caleb Matthew Dechant, Hamid Moradkhani Jun 2014

Toward A Reliable Prediction Of Seasonal Forecast Uncertainty: Addressing Model And Initial Condition Uncertainty With Ensemble Data Assimilation And Sequential Bayesian Combination, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Uncertainties are an unfortunate yet inevitable part of any forecasting system. Within the context of seasonal hydrologic predictions, these uncertainties can be attributed to three causes: imperfect characterization of initial conditions, an incomplete knowledge of future climate and errors within computational models. This study proposes a method to account for all threes sources of uncertainty, providing a framework to reduce uncertainty and accurately convey persistent predictive uncertainty. In currently available forecast products, only a partial accounting of uncertainty is performed, with the focus primarily on meteorological forcing. For example, the Ensemble Streamflow Prediction (ESP) technique uses meteorological climatology to estimate …


Bicycle Facilities And The Uptake Of Air Pollution By Active Travelers, Alexander Y. Bigazzi, Miguel A. Figliozzi, James F. Pankow, Wentai Luo, Lorne M. Isabelle Mar 2014

Bicycle Facilities And The Uptake Of Air Pollution By Active Travelers, Alexander Y. Bigazzi, Miguel A. Figliozzi, James F. Pankow, Wentai Luo, Lorne M. Isabelle

Civil and Environmental Engineering Faculty Publications and Presentations

Outlines the research of urban bicyclists' facilities and the uptake of air pollution by active travelers in urban Portland, OR. Outlines the research goals, beginning data collection methods, intake/uptake, modeling results, conclusions and the next steps for future work with the collected data set of direct uptake measurements.


A Novel Approach To Flow Estimation In Tidal Rivers, Hamed Moftakhari Rostamkhani, David A. Jay, Stefan A. Talke, Tobias Kukulka, Peter D. Bromirski Aug 2013

A Novel Approach To Flow Estimation In Tidal Rivers, Hamed Moftakhari Rostamkhani, David A. Jay, Stefan A. Talke, Tobias Kukulka, Peter D. Bromirski

Civil and Environmental Engineering Faculty Publications and Presentations

Reliable estimation of river discharge to the ocean from large tidal rivers is vital for water resources management and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, flow records are often limited in length and/or quality and tidal records often predate discharge records. Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. We use this phenomenon to develop a method of estimating river discharge for time periods with tidal data but no flow record. Employing sequential 32 day harmonic analyses of tidal properties, …


Model For Acid-Base Chemistry In Nanoparticle Growth (Mabnag), Taina Yli-Juuti, Kelley Barsanti, L. Hildebrandt Ruiz, Antti-Jussi Kieloaho, U. Makkonen, Tuukka Petäjä, Taina Ruuskanen, Markku Kulmala, Ilona Riipinen Jan 2013

Model For Acid-Base Chemistry In Nanoparticle Growth (Mabnag), Taina Yli-Juuti, Kelley Barsanti, L. Hildebrandt Ruiz, Antti-Jussi Kieloaho, U. Makkonen, Tuukka Petäjä, Taina Ruuskanen, Markku Kulmala, Ilona Riipinen

Civil and Environmental Engineering Faculty Publications and Presentations

Climatic effects of newly-formed atmospheric secondary aerosol particles are to a large extent determined by their condensational growth rates. However, all the vapours condensing on atmospheric nanoparticles and growing them to climatically relevant sizes are not identified yet and the effects of particle phase processes on particle growth rates are poorly known. Besides sulfuric acid, organic compounds are known to contribute significantly to atmospheric nanoparticle growth. In this study a particle growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) was developed to study the effect of salt formation on nanoparticle growth, which has been proposed as a potential …


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 …


Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith Jan 2012

Identification Of The Biogenic Compounds Responsible For Size-Dependent Nanoparticle Growth, Paul M. Winkler, John Ortega, Thomas Karl, Luca Cappellin, Hans R. Friedli, Kelley Barsanti, Peter H. Mcmurry, James N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

The probability that freshly nucleated nanoparticles can survive to become cloud condensation nuclei is highly sensitive to particle growth rates. Much of the growth of newly formed ambient nanoparticles can be attributed to oxidized organic vapors originating from biogenic precursor gases. In this study we investigated the chemical composition of size-selected biogenic nanoparticles in the size range from 10 to 40 nm. Particles were formed in a flow tube reactor by ozonolysis ofα-pinene and analyzed with a Thermal Desorption Chemical Ionization Mass Spectrometer. While we found similar composition in 10 and 20 nm particles, the relative amounts of …


Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet Sep 2011

Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet

Civil and Environmental Engineering Faculty Publications and Presentations

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include …


The Potential Contribution Of Organic Salts To New Particle Growth, Kelley Barsanti, Peter H. Mcmurry, J. N. Smith Jan 2009

The Potential Contribution Of Organic Salts To New Particle Growth, Kelley Barsanti, Peter H. Mcmurry, J. N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

Field and lab measurements suggest that low-molecular weight (MW) organic acids and bases exist in accumulation and nucleation mode particles, despite their relatively high pure-liquid vapor pressures. The mechanism(s) by which such compounds contribute to the mass growth of existing aerosol particles and newly formed particles has not been thoroughly explored. One mechanism by which low- MW compounds may contribute to new particle growth is through the formation of organic salts. In this paper we use thermodynamic modeling to explore the potential for organic salt formation by atmospherically relevant organic acids and bases for two system types: one in which …


New Particle Formation In The Front Range Of The Colorado Rocky Mountains, Micahel Boy, Thomas Karl, Andrew Turnipseed, Roy Lee Mauldin, Edward Kosciuch, James Greenberg, Jeff Rathbone, James Smith, Andreas Held, Kelley Barsanti, Alex Guenther Jan 2008

New Particle Formation In The Front Range Of The Colorado Rocky Mountains, Micahel Boy, Thomas Karl, Andrew Turnipseed, Roy Lee Mauldin, Edward Kosciuch, James Greenberg, Jeff Rathbone, James Smith, Andreas Held, Kelley Barsanti, Alex Guenther

Civil and Environmental Engineering Faculty Publications and Presentations

New particle formation is of interest because of its influence on the properties of aerosol population, and due to the possible contribution of newly formed particles to cloud condensation nuclei. Currently no conclusive evidence exists as to the mechanism or mechanisms of nucleation and subsequent particle growth. However, nucleation rates exhibit a clear dependence on ambient sulphuric acid concentrations and particle growth is often attributed to the condensation of organic vapours. A detailed study of new particle formation in the Front Range of the Colorado Rocky Mountains is presented here. Gas and particle measurement data for 32 days was analyzed …


Pend Oreille River, Box Canyon Model: Model Scenario Simulations, Chris Berger, Robert Leslie Annear, Scott A. Wells Jul 2007

Pend Oreille River, Box Canyon Model: Model Scenario Simulations, Chris Berger, Robert Leslie Annear, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Washington Department of Ecology is interested in developing a temperature Total Maximum Daily Load (TMDL) allocation for the Pend Oreille River between the Albeni Falls Dam (U.S. Army Corps of Engineer’s reservoir) and Box Canyon Dam as shown in Figure 1. The Pend Oreille drainage basin is shown in Figure 2. An existing model of the Box Canyon reach was updated from CE-QUALW2 Version 3.0 to Version 3.5. This current research involves improving the calibration of the original model (1997 and 1998) and expanding the model using 2004 as an additional data set for calibration.

The use of field …


Modeling Effects Of Channel Complexity And Hyporheic Flow On Stream Temperatures, Chris Berger, Scott A. Wells Jun 2007

Modeling Effects Of Channel Complexity And Hyporheic Flow On Stream Temperatures, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Stream temperatures are affected by multiple forcing functions, including surface heat exchange (including solar radiation, evaporation, conduction, and net long wave radiation) and hyporheic flows. Each of these forcing functions is directly influenced by the level of channel complexity in the stream channel and riparian shading. The interrelationship between channel complexity, hyporheic flow and stream temperature is highly complex, and efforts to manage for habitat diversity by managing channel complexity could result in unintended consequences on stream temperature. When planning modifications to stream channel complexity, consideration should be given to the effects such moderations could have on stream temperatures.

Urbanization …