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Upper Mississippi River Basin Modeling System Part 4: Climate Change Impacts On Flow And Water Quality, Eugene S. Takle, Chris Anderson, Manoj Jha, Philip W. Gassman 2017 Iowa State University

Upper Mississippi River Basin Modeling System Part 4: Climate Change Impacts On Flow And Water Quality, Eugene S. Takle, Chris Anderson, Manoj Jha, Philip W. Gassman

Eugene Takle

Output from an ensemble of seven global climate models for contemporary and future scenario climates was used to drive the Soil and Water Assessment Tool (SWAT) to examine components of the hydrologic budget for the Upper Mississippi River Basin (UMRB). Results showed only modest increases in precipitation (+6%) and streamflow (+3%) but substantial reduction in snowfall (-37%) for the UMRB for the end of the 21st century. The low-resolution of global models contribute to the biases in some but not all hydrologic components, most notably evapotranspiration, potential evapotranspiration, and baseflow. Ensemble results indicate an increase in baseflow (+12%) and ...


Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman 2017 Plymouth Marine Laboratory

Estimation Of Bubble-Mediated Air–Sea Gas Exchange From Concurrent Dms And Co2 Transfer Velocities At Intermediate–High Wind Speeds, Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. De Bruyn, Adrian H. Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Simultaneous air–sea fluxes and concentration differences of dimethylsulfide (DMS) and carbon dioxide (CO2/ were measured during a summertime North Atlantic cruise in 2011. This data set reveals significant differences between the gas transfer velocities of these two gases (1kw/ over a range of wind speeds up to 21ms􀀀1. These differences occur at and above the approximate wind speed threshold when waves begin breaking. Whitecap fraction (a proxy for bubbles) was also measured and has a positive relationship with 1kw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However ...


Using Bolide Airwaves To Estimate Meteoroid Source Characteristics And Window Damage Potential, Nayeob Gi 2017 The University of Western Ontario

Using Bolide Airwaves To Estimate Meteoroid Source Characteristics And Window Damage Potential, Nayeob Gi

Electronic Thesis and Dissertation Repository

We examined the far-field infrasonic signals produced by 78 bolides simultaneously detected by U.S. government sensors to determine the mechanisms responsible for interstation spreads in infrasound signal period. These signal period spreads lead to large variances in source energy estimates. Our analysis suggests that while acoustic source height contributes to some extent to the variance in signal periods, the range from the source to the station and in particular station noise plays a more significant role.

By simulating the near-field weak shocks from a suite of well-observed energetic fireballs, we have empirically estimated how often fireball shocks produce overpressure ...


A Review Of Passive Sampling Systems For Ambient Air Mercury Measurements, Jiaoyan Huang, Seth N. Lyman, Jelena Stamenkovic Hartman, Mae Sexauer Gustin 2017 Utah State University

A Review Of Passive Sampling Systems For Ambient Air Mercury Measurements, Jiaoyan Huang, Seth N. Lyman, Jelena Stamenkovic Hartman, Mae Sexauer Gustin

Seth Lyman

Atmospheric mercury (Hg) temporal and spatial patterns must be measured accurately in order to adequately understand the role of this pathway as it relates to Hg toxicity and exposure of humans and wildlife to Hg. It is also important to understand the distribution of the different chemical forms (elemental, oxidized, or particle bound) and specific compounds in air (e.g., HgCl2, HgBr2, HgO, Hg(NO3)2, and HgSO4). However, the current automated and passive sampling methods of measurement have limitations and artifacts impacting our ability to achieve this task. Both abiotic and biotic systems have been developed to measure the ...


Atmospheric Mercury Concentrations And Speciation Measured From 2004 To 2007 In Reno, Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin 2017 Utah State University

Atmospheric Mercury Concentrations And Speciation Measured From 2004 To 2007 In Reno, Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin

Seth Lyman

Atmospheric elemental, reactive and particulate mercury (Hg) concentrations were measured north of downtown Reno, Nevada, USA from November 2004 to November 2007. Three-year mean and median concentrations for gaseous elemental Hg (Hg0) were 1.6 and 1.5 ng m−3 (respectively), similar to global mean Hg0 concentrations. The three-year mean reactive gaseous Hg (RGM) concentration (26 pg m−3) was higher than values reported for rural sites across the western United States. Well defined seasonal and daily patterns in Hg0 and RGM concentrations were observed, with the highest Hg0 concentrations measured in winter and early morning, and RGM concentrations ...


A Passive Sampler For Ambient Gaseous Oxidized Mercury Concentrations, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo 2017 Utah State University

A Passive Sampler For Ambient Gaseous Oxidized Mercury Concentrations, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo

Seth Lyman

This paper reports on the development of a passive sampler for estimating gaseous oxidized mercury concentrations. Atmospheric gaseous oxidized mercury concentrations calculated from passive sampler data were correlated with those obtained using an automated analyzer (r2 = 0.71, p < 0.01, n = 110 for one-week deployments; r2 = 0.89, p < 0.01, n = 22 for two-week deployments). Sampler uptake was not significantly affected by changes in temperature, humidity, or ozone concentration, but it was slightly dependent on wind speed. As such, an equation for correcting data due to this factor was developed based on wind tunnel and field data. The ...


Speciation Of Atmospheric Mercury At Two Sites In Northern Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin 2017 Utah State University

Speciation Of Atmospheric Mercury At Two Sites In Northern Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin

Seth Lyman

Gaseous elemental mercury (Hg0), reactive gaseous mercury (RGM), and mercury bound to particles (Hgp) were measured during seasonal 1- or 2-week data collection campaigns at two Mercury Deposition Network sites (NV02 and NV99) in northern Nevada, USA. The sites are rural but are located in an area of diverse natural and anthropogenic mercury sources that include undisturbed and mining mercury-disturbed enriched substrates, coal-fired power plants, ore processing facilities, and industrial facilities. Concentrations of Hg0 averaged over all campaigns were 3.0±1.7 ng m−3 at NV02 and 2.5±3.1 ng m−3 at NV99, higher than ...


Progress On Understanding Atmospheric Mercury Hampered By Uncertain Measurements, Daniel A. Jaffe, Seth N. Lyman, Helen M. Amosl, Mae Sexauer Gustin, Jiaoyan Huang, Noelle E. Selin, Leonard Levin, Arnout ter Schure, Robert P. Mason, Robert Talbot, Andrew Rutter, Brandon Finley, Lyatt Jaeglé, Viral Shah, Crystal McClure, Jesse Ambrose, Lynne Gratz, Steven Lindberg, Peter Weiss-Penzias, Guey-Rong Sheu, Dara Feddersen, Milena Horvat, Ashu Dastoor, Anthony J. Hynes, Huiting Mao, Jeroen E. Sonke, Franz Slemr, Jenny A. Fisher, Ralf Ebinghaus, Yanxu Zhang, Grant Edwards 2017 Utah State University

Progress On Understanding Atmospheric Mercury Hampered By Uncertain Measurements, Daniel A. Jaffe, Seth N. Lyman, Helen M. Amosl, Mae Sexauer Gustin, Jiaoyan Huang, Noelle E. Selin, Leonard Levin, Arnout Ter Schure, Robert P. Mason, Robert Talbot, Andrew Rutter, Brandon Finley, Lyatt Jaeglé, Viral Shah, Crystal Mcclure, Jesse Ambrose, Lynne Gratz, Steven Lindberg, Peter Weiss-Penzias, Guey-Rong Sheu, Dara Feddersen, Milena Horvat, Ashu Dastoor, Anthony J. Hynes, Huiting Mao, Jeroen E. Sonke, Franz Slemr, Jenny A. Fisher, Ralf Ebinghaus, Yanxu Zhang, Grant Edwards

Seth Lyman

Mercury (Hg) is a potent neurotoxin and globally reducing environmental levels is seen as paramount for protecting human and wildlife health. In 2013, many countries finalized the negotiations on, and have now signed, the Minamata Convention on Mercury, which commits participating countries to reduce emissions and use of mercury. Successful implementation of the treaty will require adequate verification through global monitoring.


Release Of Mercury Halides From Kcl Denuders In The Presence Of Ozone, Seth N. Lyman, Daniel A. Jaffe, Mae S. Gustin 2017 Utah State University

Release Of Mercury Halides From Kcl Denuders In The Presence Of Ozone, Seth N. Lyman, Daniel A. Jaffe, Mae S. Gustin

Seth Lyman

KCl-coated denuders have become a standard method for measurement of gaseous oxidized mercury, but their performance has not been exhaustively evaluated, especially in field conditions. In this study, KCl-coated and uncoated quartz denuders loaded with HgCl2 and HgBr2 lost 29–55% of these compounds, apparently as elemental mercury, when exposed to ozone (range of 6–100 ppb tested). This effect was also observed for denuders loaded with gaseous oxidized mercury at a field site in Nevada (3–37% of oxidized mercury lost). In addition, collection efficiency decreased by 12–30% for denuders exposed to 50 ppb ozone during ...


Testing And Application Of Surrogate Surfaces For Understanding Potential Gaseous Oxidized Mercury Dry Deposition, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo, Phillip I. Kilner, Eric Edgerton, Ben Hartsell 2017 Utah State University

Testing And Application Of Surrogate Surfaces For Understanding Potential Gaseous Oxidized Mercury Dry Deposition, Seth N. Lyman, Mae Sexauer Gustin, Eric M. Prestbo, Phillip I. Kilner, Eric Edgerton, Ben Hartsell

Seth Lyman

Currently there is no standard method for measurement of atmospheric mercury dry deposition. While all operationally defined forms of atmospheric mercury (elemental, oxidized, and particulate) can be dry deposited, oxidized forms are of concern due to high deposition velocities, water solubility, and reactivity. This paper describes the development of a surrogate surface for characterizing potential dry deposition of gaseous oxidized mercury (GOM). Laboratory tests showed that the surface collected HgCl2, HgBr2, and HgO with equal efficiency, and deposition was not significantly influenced by temperature, humidity, or ozone concentrations. Deposition of mercury to surfaces in field deployments was correlated with GOM ...


Sources Of Gaseous Oxidized Mercury And Mercury Dry Deposition At Two Southeastern U.S. Sites, Peter S. Weiss-Penzias, Mae S. Gustin, Seth N. Lyman 2017 Utah State University

Sources Of Gaseous Oxidized Mercury And Mercury Dry Deposition At Two Southeastern U.S. Sites, Peter S. Weiss-Penzias, Mae S. Gustin, Seth N. Lyman

Seth Lyman

Wet deposition measurements have shown that relative to other parts of the US, the southeastern region has the highest mercury (Hg) inputs. The source of this Hg has been investigated by multiple researchers and is suggested to be derived from local, regional and global sources. Here we focus on trying to understand potential sources of Hg to this area during periods dominated by dry gaseous oxidized mercury (GOM) deposition. Dry deposition of GOM to a surrogate surface was measured in conjunction with speciated atmospheric Hg, and ancillary parameters from September 2007 through September 2008 at two sites located within 25 ...


Seasonal And Diel Variation Of Atmospheric Mercury Concentrations In The Reno (Nevada, Usa) Airshed, Jelena Stamenkovic, Seth Lyman, Mae S. Gustin 2017 Utah State University

Seasonal And Diel Variation Of Atmospheric Mercury Concentrations In The Reno (Nevada, Usa) Airshed, Jelena Stamenkovic, Seth Lyman, Mae S. Gustin

Seth Lyman

This paper describes total gaseous mercury (TGM) concentrations measured in Reno, Nevada from 2002 to 2005. The 3-year mean and median air Hg concentrations were 2.3 and 2.1 ng m−3, respectively. Mercury concentrations exhibited seasonality, with the highest concentrations in winter, and the lowest in summer and fall. A well-defined diel pattern in TGM concentration was observed, with maximum daily concentrations observed in the morning and minimum in the afternoon. A gradual increase of TGM concentration was observed in the evening and over night. The early morning increase in TGM was likely due to activation of local ...


The Magnitude Of The Snow-Sourced Reactive Nitrogen Flux To The Boundary Layer In The Uintah Basin, Maria Zakto, Joseph Erbland, Joel Savarino, Lei Geng, Lauren Easley, Andrew Schauer, Timothy Bates, Patricia K. Quinn, Bonnie Light, David Morison, Hans D. Osthoff, Seth Lyman, William Neff, Bin Yuan, Becky Alexander 2017 Utah State University

The Magnitude Of The Snow-Sourced Reactive Nitrogen Flux To The Boundary Layer In The Uintah Basin, Maria Zakto, Joseph Erbland, Joel Savarino, Lei Geng, Lauren Easley, Andrew Schauer, Timothy Bates, Patricia K. Quinn, Bonnie Light, David Morison, Hans D. Osthoff, Seth Lyman, William Neff, Bin Yuan, Becky Alexander

Seth Lyman

Reactive nitrogen (Nr = NO, NO2, HONO) and volatile organic carbon emissions from oil and gas extraction activities play a major role in wintertime ground-level ozone exceedance events of up to 140 ppb in the Uintah Basin in eastern Utah. Such events occur only when the ground is snow covered, due to the impacts of snow on the stability and depth of the boundary layer and ultraviolet actinic flux at the surface. Recycling of reactive nitrogen from the photolysis of snow nitrate has been observed in polar and midlatitude snow, but snow-sourced reactive nitrogen fluxes in mid-latitude regions have not yet ...


Collaborative Research: Refining And Testing Methods For Identifying And Quantifying Gaseous Oxidized Mercury In Air, Seth Lyman 2017 Utah State University

Collaborative Research: Refining And Testing Methods For Identifying And Quantifying Gaseous Oxidized Mercury In Air, Seth Lyman

Seth Lyman

No abstract provided.


Mercury Exchange Between The Atmosphere And Low Mercury Containing Substrates, Mae Sexauer Gustin, Mark Engle, Jody Ericksen, Seth N. Lyman, Jelena Stamenkovic, Mei Xin 2017 Utah State University

Mercury Exchange Between The Atmosphere And Low Mercury Containing Substrates, Mae Sexauer Gustin, Mark Engle, Jody Ericksen, Seth N. Lyman, Jelena Stamenkovic, Mei Xin

Seth Lyman

Mercury is emitted to the air from Hg-enriched and low Hg-containing (natural background) substrates. Emitted Hg can be geogenic, or can be derived from the re-emission of Hg that was previously deposited to the soil from the atmosphere. Atmospheric Hg can be derived from natural and/or anthropogenic sources and can be deposited by wet or dry processes. It is important to understand the relative magnitude of emission, deposition, and re-emission of Hg associated with terrestrial ecosystems with natural background soil Hg concentrations because these landscapes cover large terrestrial surface areas. This information is also important for developing biogeochemical mass ...


Development, Testing, And Deployment Of An Air Sampling Manifold For Spiking Elemental And Oxidized Mercury During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), B. D. Finley, D. A. Jaffe, K. Call, Seth Lyman, M. Sexauer Gustin, C. Peterson, M. Miller, T. Lyman 2017 Utah State University

Development, Testing, And Deployment Of An Air Sampling Manifold For Spiking Elemental And Oxidized Mercury During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), B. D. Finley, D. A. Jaffe, K. Call, Seth Lyman, M. Sexauer Gustin, C. Peterson, M. Miller, T. Lyman

Seth Lyman

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was in Reno, NV from August 22, 2011 to September 16, 2011. The goals of the experiment were to compare existing and new methods for measurements of ambient elemental and oxidized Hg, and to test these with quantitative spikes of Hg0, HgBr2, O3 and water vapor. In this paper we describe the design, testing, and deployment of a high flow manifold system designed to deliver ambient air and spiked compounds to multiple instruments simultaneously. The manifold was constructed of 1” OD PFA tubing and heated to 115 °C for the entire active zone ...


Development Of A Passive Sampler For Gaseous Mercury, Mae S. Gustin, Seth N. Lyman, P. Kilner, E. Prestbo 2017 Utah State University

Development Of A Passive Sampler For Gaseous Mercury, Mae S. Gustin, Seth N. Lyman, P. Kilner, E. Prestbo

Seth Lyman

Here we describe work toward development of the components of a cost effective passive sampling system for gaseous Hg that could be broadly deployed by nontechnical staff. The passive sampling system included an external shield to reduce turbulence and exposure to precipitation and dust, a diffusive housing that directly protects the collection surface during deployment and handling, and a collection surface. A protocol for cleaning and deploying the sampler and an analytical method were developed. Our final design consisted of a polycarbonate external shield enclosing a custom diffusive housing made from expanded PTFE tubing. Two collection surfaces were investigated, gold ...


Automated Calibration Of Atmospheric Oxidized Mercury Measurements, Seth Lyman, Colleen Jones, Trevor O'Neil, Tanner Allen, Matthieu Miller, Mae Sexauer Gustin, Ashley M. Pierce, Winston Luke, Xinrong Ren, Paul Kelley 2017 Utah State University

Automated Calibration Of Atmospheric Oxidized Mercury Measurements, Seth Lyman, Colleen Jones, Trevor O'Neil, Tanner Allen, Matthieu Miller, Mae Sexauer Gustin, Ashley M. Pierce, Winston Luke, Xinrong Ren, Paul Kelley

Seth Lyman

The atmosphere is an important reservoir for mercury pollution, and understanding of oxidation processes is essential to elucidating the fate of atmospheric mercury. Several recent studies have shown that a low bias exists in a widely applied method for atmospheric oxidized mercury measurements. We developed an automated, permeation tube-based calibrator for elemental and oxidized mercury, and we integrated this calibrator with atmospheric mercury instrumentation (Tekran 2537/1130/1135 speciation systems) in Reno, Nevada and at Mauna Loa Observatory, Hawaii, U.S.A. While the calibrator has limitations, it was able to routinely inject stable amounts of HgCl2 and HgBr2 into ...


Atmospheric Mercury Concentrations And Speciation Measured From 2004 To 2007 In Reno, Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin 2017 Utah State University

Atmospheric Mercury Concentrations And Speciation Measured From 2004 To 2007 In Reno, Nevada, Usa, Seth N. Lyman, Mae Sexauer Gustin

Seth Lyman

Atmospheric elemental, reactive and particulate mercury (Hg) concentrations were measured north of downtown Reno, Nevada, USA from November 2004 to November 2007. Three-year mean and median concentrations for gaseous elemental Hg (Hg0) were 1.6 and 1.5 ng m−3 (respectively), similar to global mean Hg0 concentrations. The three-year mean reactive gaseous Hg (RGM) concentration (26 pg m−3) was higher than values reported for rural sites across the western United States. Well defined seasonal and daily patterns in Hg0 and RGM concentrations were observed, with the highest Hg0 concentrations measured in winter and early morning, and RGM concentrations ...


Fast Time Resolution Oxidized Mercury Measurements During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), Jesse L. Ambrose, Seth N. Lyman, Jiaoyan Huang, Mae Sexauer Gustin, Daneil A. Jaffe 2017 Utah State University

Fast Time Resolution Oxidized Mercury Measurements During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), Jesse L. Ambrose, Seth N. Lyman, Jiaoyan Huang, Mae Sexauer Gustin, Daneil A. Jaffe

Seth Lyman

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was carried out from 22 August to 16 September, 2011 in Reno, NV to evaluate the performance of new and existing methods to measure atmospheric mercury (Hg). Measurements were made using a common sampling manifold to which controlled concentrations of Hg species, including gaseous elemental mercury (GEM) and HgBr2 (a surrogate gaseous oxidized mercury (GOM) compound), and potential interferents were added. We present an analysis of Hg measurements made using the University of Washington’s Detector for Oxidized Hg Species (DOHGS), focusing on tests of GEM and HgBr2 spike recovery, the potential for ...


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