Gregory Wetherbee is a Research Chemist for the USGS Water Resources Mission Area.
Science and Products
U.S. Geological Survey Precipitation Chemistry Quality Assurance Project Data 2019 – 2020
The USGS Precipitation Chemistry Quality Assurance Project (PCQA) operates QA programs to challenge and test the National Atmospheric Deposition Program (NADP) data-collection processes for both the National Trends Network (NTN) and Mercury Deposition Network (MDN). PCQA data are available in separate tables for each quality-assurance program: (1) NTN Interlaboratory-comparison, (2) MDN Interlabor
Data for the U.S. Geological Survey Precipitation Chemistry Quality Assurance Project for the National Atmospheric Deposition Program, 1978-2017
The U.S. Geological Survey has operated the Precipitation Chemistry Quality Assurance (PCQA) Project to evaluate and document the data quality for the National Atmospheric Deposition Program (NADP) for 40 years. The PCQA is primarily focused on data quality for the NADP National Trends Network (NTN) and Mercury Deposition Network (MDN). The PCQA implements programs to evaluate the variability and
Filter Total Items: 40
Inter-comparison of measurements of inorganic chemical components in precipitation from NADP and CAPMoN at collocated sites in the USA and Canada during 1986–2019
Wet deposition monitoring is a critical part of the long-term monitoring of acid deposition, which aims to assess the ecological impact of anthropogenic emissions of SO2 and NOx. In North America, long-term wet deposition has been monitored through two national networks: the Canadian Air and Precipitation Monitoring Network (CAPMoN) and the US National Atmospheric Deposition Program (NADP), for Ca
Authors
Jian Feng, Amanda Cole, Gregory A. Wetherbee, Kulbir Banwait
Initial comparison of pollen counting methods using precipitation and ambient air samples and automated artificial intelligence to support national monitoring objectives
Given the endemic nature of pollen throughout the environment, the impact upon human health, and the need for more extensive and better measurements of pollen in the USA, a preliminary project within the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) was developed. Pollen was measured in ambient air by several methods and in precipitation wet deposition samples at t
Authors
Gregory A. Wetherbee, David A. Gay, Eric Uram, Terri Williams, Andrew Johnson
Atmospheric deposition of inorganic reactive nitrogen at the Rocky Flats National Wildlife Refuge, 2017–19
The Rocky Flats National Wildlife Refuge (RFNWR) in Colorado is home to increasingly rare, xeric tallgrass prairie. The RFNWR is also located near many combustion and agricultural sources of inorganic reactive nitrogen (Nr), which emit Nr to the atmosphere. Wet atmospheric deposition of Nr was monitored at RFNWR during 2017–19 by the U.S. Geological Survey in cooperation with the U.S. Fish and Wil
Authors
Gregory A. Wetherbee
External quality-assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2019–20
The U.S. Geological Survey Precipitation Chemistry Quality Assurance project (PCQA) operated four distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2019–20. The NTN programs included (1) a field audit program to evaluate sample contamination and stabil
Authors
Gregory A. Wetherbee, RoseAnn Martin, Alexander Liethen
Nitrogen isotopes indicate vehicle emissions and biomass burning dominate ambient ammonia across Colorado's Front Range urban corridor
Urban ammonia (NH3) emissions contribute to poor local air quality and can be transported to rural landscapes, impacting sensitive ecosystems. The Colorado Front Range urban corridor encompasses the Denver Metropolitan Area, rural farmland/rangeland and montane forest between the city and the Rocky Mountains. Reactive nitrogen emissions from the corridor are partly responsible for increased N depo
Authors
J. David Felix, Alexander Berner, Gregory A. Wetherbee, Sheila F. Murphy, Ruth C. Heindel
Elevated nitrogen deposition to fire-prone forests adjacent to urban and agricultural areas, Colorado front range, USA
As humans increasingly dominate the nitrogen cycle, deposition of reactive nitrogen (Nr) will continue to have adverse consequences for ecosystems. In the Rocky Mountains, Nr deposition remains elevated and has become increasingly dominated by ammonium, despite efforts to reduce emissions. Currently, spatial models of Nr deposition do not fully account for urban and agricultural emissions, sources
Authors
Ruth C. Heindel, Sheila F. Murphy, Deborah A. Repert, Gregory A. Wetherbee, Alexander Liethen, David W. Clow, Toby A. Halamka
Estimating urban air pollution contribution to South Platte River nitrogen loads with National Atmospheric Deposition Program data and SPARROW model
Air pollution is commonly disregarded as a source of nutrient loading to impaired surface waters managed under the Clean Water Act per states’ 303(d) list programs. The contribution of air pollution to 2017–2018 South Platte River nitrogen (N) loads was estimated from the headwaters to the gage at Weldona, Colorado, USA (100 km downstream of Denver), using data from the National Atmospheric Deposi
Authors
Gregory A. Wetherbee, Michael Wieczorek, Dale M. Robertson, David A. Saad, Jon Novick, Alisa Mast
Trends in precipitation chemistry across the U.S. 1985–2017: Quantifying the benefits from 30 years of Clean Air Act amendment regulation
Acid rain was first recognized in the 1970s in North America and Europe as an atmospheric pollutant that was causing harm to ecosystems. In response, the U.S. Congress enacted Title IV of the Clean Air Act Amendments (CAA) in 1990 to reduce sulfur and nitrogen emissions from fossil fuel burning power plants. This study reports trends in wet-precipitation chemistry in response to emissions reductio
Authors
Michael McHale, Amy Ludtke, Gregory A. Wetherbee, Douglas A. Burns, Mark A. Nilles, Jason S. Finkelstein
External quality assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2017–18
The U.S. Geological Survey (USGS) Precipitation Chemistry Quality Assurance project (PCQA) operated five distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network and Mercury Deposition Network during 2017–18. The National Trends Network programs included (1) a field audit program to evaluate sample contamina
Authors
Gregory A. Wetherbee, RoseAnn Martin
A new sampler for the collection and retrieval of dry dust deposition
Atmospheric dust can influence biogeochemical cycles, accelerate snowmelt, and affect air, water quality, and human health. Yet, the bulk of atmospherically transported material remains poorly quantified in terms of total mass fluxes and composition. This lack of information stems in part from the challenges associated with measuring dust deposition. Here we report on the design and efficacy of a
Authors
J. Brahney, Gregory A. Wetherbee, Graham A. Sexstone, C. Youngbull, P. Strong, Ruth C. Heindel
2017 Monitoring and tracking wet nitrogen deposition at Rocky Mountain National Park
The Colorado Department of Public Health and Environment (CDPHE), the National Park Service (NPS), and the U.S. Environmental Protection Agency (EPA) issued the Nitrogen Deposition Reduction Plan (NDRP) in 2007 to address the effects and trends of nitrogen deposition at Rocky Mountain National Park (RMNP). The agencies chose a glidepath approach to reduce wet nitrogen deposition to a level of 1.5
Authors
Kristi Morris, M. Alisa Mast, Gregory A. Wetherbee, Jill S. Baron, Jim Cheatham, Jim Bromberg, Lisa Devore, James Hou, Kristi Gebhart, Mike Bell, David Gay, Michael Olson, Timothy Weinmann, Daniel Bowker
Science needs for continued development of total nitrogen deposition budgets in the United States
The objectives of this white paper are to describe the state of the science with respect to total Nr deposition budgets in North America and the research needed to improve these budgets from both a measurement and modeling standpoint. The document is intended to serve as a plan for TDep research activities but also, more broadly, to provide program managers, natural resource managers, policy make
Authors
Gregory A. Wetherbee, Pamela H. Templar, Richard V. Pouyat, Stephen M. Decina, Brian M. Kerschner, Thomas H. Whitlow, Pamela E. Padgett, Donna B. Schwede, Jill Baron, David Clow, Alisa Mast, Graham A. Sexstone, Kristi H. Morris
Science and Products
- Data
U.S. Geological Survey Precipitation Chemistry Quality Assurance Project Data 2019 – 2020
The USGS Precipitation Chemistry Quality Assurance Project (PCQA) operates QA programs to challenge and test the National Atmospheric Deposition Program (NADP) data-collection processes for both the National Trends Network (NTN) and Mercury Deposition Network (MDN). PCQA data are available in separate tables for each quality-assurance program: (1) NTN Interlaboratory-comparison, (2) MDN InterlaborData for the U.S. Geological Survey Precipitation Chemistry Quality Assurance Project for the National Atmospheric Deposition Program, 1978-2017
The U.S. Geological Survey has operated the Precipitation Chemistry Quality Assurance (PCQA) Project to evaluate and document the data quality for the National Atmospheric Deposition Program (NADP) for 40 years. The PCQA is primarily focused on data quality for the NADP National Trends Network (NTN) and Mercury Deposition Network (MDN). The PCQA implements programs to evaluate the variability and - Publications
Filter Total Items: 40
Inter-comparison of measurements of inorganic chemical components in precipitation from NADP and CAPMoN at collocated sites in the USA and Canada during 1986–2019
Wet deposition monitoring is a critical part of the long-term monitoring of acid deposition, which aims to assess the ecological impact of anthropogenic emissions of SO2 and NOx. In North America, long-term wet deposition has been monitored through two national networks: the Canadian Air and Precipitation Monitoring Network (CAPMoN) and the US National Atmospheric Deposition Program (NADP), for CaAuthorsJian Feng, Amanda Cole, Gregory A. Wetherbee, Kulbir BanwaitInitial comparison of pollen counting methods using precipitation and ambient air samples and automated artificial intelligence to support national monitoring objectives
Given the endemic nature of pollen throughout the environment, the impact upon human health, and the need for more extensive and better measurements of pollen in the USA, a preliminary project within the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) was developed. Pollen was measured in ambient air by several methods and in precipitation wet deposition samples at tAuthorsGregory A. Wetherbee, David A. Gay, Eric Uram, Terri Williams, Andrew JohnsonAtmospheric deposition of inorganic reactive nitrogen at the Rocky Flats National Wildlife Refuge, 2017–19
The Rocky Flats National Wildlife Refuge (RFNWR) in Colorado is home to increasingly rare, xeric tallgrass prairie. The RFNWR is also located near many combustion and agricultural sources of inorganic reactive nitrogen (Nr), which emit Nr to the atmosphere. Wet atmospheric deposition of Nr was monitored at RFNWR during 2017–19 by the U.S. Geological Survey in cooperation with the U.S. Fish and WilAuthorsGregory A. WetherbeeExternal quality-assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2019–20
The U.S. Geological Survey Precipitation Chemistry Quality Assurance project (PCQA) operated four distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2019–20. The NTN programs included (1) a field audit program to evaluate sample contamination and stabilAuthorsGregory A. Wetherbee, RoseAnn Martin, Alexander LiethenNitrogen isotopes indicate vehicle emissions and biomass burning dominate ambient ammonia across Colorado's Front Range urban corridor
Urban ammonia (NH3) emissions contribute to poor local air quality and can be transported to rural landscapes, impacting sensitive ecosystems. The Colorado Front Range urban corridor encompasses the Denver Metropolitan Area, rural farmland/rangeland and montane forest between the city and the Rocky Mountains. Reactive nitrogen emissions from the corridor are partly responsible for increased N depoAuthorsJ. David Felix, Alexander Berner, Gregory A. Wetherbee, Sheila F. Murphy, Ruth C. HeindelElevated nitrogen deposition to fire-prone forests adjacent to urban and agricultural areas, Colorado front range, USA
As humans increasingly dominate the nitrogen cycle, deposition of reactive nitrogen (Nr) will continue to have adverse consequences for ecosystems. In the Rocky Mountains, Nr deposition remains elevated and has become increasingly dominated by ammonium, despite efforts to reduce emissions. Currently, spatial models of Nr deposition do not fully account for urban and agricultural emissions, sourcesAuthorsRuth C. Heindel, Sheila F. Murphy, Deborah A. Repert, Gregory A. Wetherbee, Alexander Liethen, David W. Clow, Toby A. HalamkaEstimating urban air pollution contribution to South Platte River nitrogen loads with National Atmospheric Deposition Program data and SPARROW model
Air pollution is commonly disregarded as a source of nutrient loading to impaired surface waters managed under the Clean Water Act per states’ 303(d) list programs. The contribution of air pollution to 2017–2018 South Platte River nitrogen (N) loads was estimated from the headwaters to the gage at Weldona, Colorado, USA (100 km downstream of Denver), using data from the National Atmospheric DeposiAuthorsGregory A. Wetherbee, Michael Wieczorek, Dale M. Robertson, David A. Saad, Jon Novick, Alisa MastTrends in precipitation chemistry across the U.S. 1985–2017: Quantifying the benefits from 30 years of Clean Air Act amendment regulation
Acid rain was first recognized in the 1970s in North America and Europe as an atmospheric pollutant that was causing harm to ecosystems. In response, the U.S. Congress enacted Title IV of the Clean Air Act Amendments (CAA) in 1990 to reduce sulfur and nitrogen emissions from fossil fuel burning power plants. This study reports trends in wet-precipitation chemistry in response to emissions reductioAuthorsMichael McHale, Amy Ludtke, Gregory A. Wetherbee, Douglas A. Burns, Mark A. Nilles, Jason S. FinkelsteinExternal quality assurance project report for the National Atmospheric Deposition Program’s National Trends Network and Mercury Deposition Network, 2017–18
The U.S. Geological Survey (USGS) Precipitation Chemistry Quality Assurance project (PCQA) operated five distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program’s (NADP) National Trends Network and Mercury Deposition Network during 2017–18. The National Trends Network programs included (1) a field audit program to evaluate sample contaminaAuthorsGregory A. Wetherbee, RoseAnn MartinA new sampler for the collection and retrieval of dry dust deposition
Atmospheric dust can influence biogeochemical cycles, accelerate snowmelt, and affect air, water quality, and human health. Yet, the bulk of atmospherically transported material remains poorly quantified in terms of total mass fluxes and composition. This lack of information stems in part from the challenges associated with measuring dust deposition. Here we report on the design and efficacy of aAuthorsJ. Brahney, Gregory A. Wetherbee, Graham A. Sexstone, C. Youngbull, P. Strong, Ruth C. Heindel2017 Monitoring and tracking wet nitrogen deposition at Rocky Mountain National Park
The Colorado Department of Public Health and Environment (CDPHE), the National Park Service (NPS), and the U.S. Environmental Protection Agency (EPA) issued the Nitrogen Deposition Reduction Plan (NDRP) in 2007 to address the effects and trends of nitrogen deposition at Rocky Mountain National Park (RMNP). The agencies chose a glidepath approach to reduce wet nitrogen deposition to a level of 1.5AuthorsKristi Morris, M. Alisa Mast, Gregory A. Wetherbee, Jill S. Baron, Jim Cheatham, Jim Bromberg, Lisa Devore, James Hou, Kristi Gebhart, Mike Bell, David Gay, Michael Olson, Timothy Weinmann, Daniel BowkerScience needs for continued development of total nitrogen deposition budgets in the United States
The objectives of this white paper are to describe the state of the science with respect to total Nr deposition budgets in North America and the research needed to improve these budgets from both a measurement and modeling standpoint. The document is intended to serve as a plan for TDep research activities but also, more broadly, to provide program managers, natural resource managers, policy makeAuthorsGregory A. Wetherbee, Pamela H. Templar, Richard V. Pouyat, Stephen M. Decina, Brian M. Kerschner, Thomas H. Whitlow, Pamela E. Padgett, Donna B. Schwede, Jill Baron, David Clow, Alisa Mast, Graham A. Sexstone, Kristi H. Morris - News