Gregory A Wetherbee
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 2021 – 2022
The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) was initiated in 1978 by the Association of State Agricultural Experiment Stations to monitor long-term atmospheric chemistry and the effects pollutants have on aquatic and terrestrial systems. As of fall 2023, precipitation was being collected at approximately 260 NTN sites in the United States, including Puerto Rico a
National Atmospheric Deposition Program Pollen Study Data for 2021 Pollen Season
Pollen was measured in ambient air by several methods and in wet atmospheric deposition samples at three monitoring sites in the National Atmospheric Deposition Program (NADP) National Trends Network. A method for counting pollen on filters was developed and provided pollen counts for NADP atmospheric wet-deposition samples and high-volume ambient air samplers (HVAS) for comparison with co-located
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
Chemical analyses and precipitation depth data for wet deposition samples collected as part of the National Atmospheric Deposition Program in the Colorado Front Range, 2017-2019
The USGS Precipitation Chemistry Quality Assurance Project (PCQA) conducts research using the infrastructure of the National Atmospheric Deposition Program (NADP) National Trends Network (NTN). Beginning in December 2016, the PCQA installed and began operating NTN monitoring sites in the Denver-Boulder metropolitan area to study urban reactive nitrogen wet deposition. Precipitation depth data are
Water-quality and stream discharge data for estimation of nitrogen loads in the South Platte River, Denver, CO, 2017-2018
The purpose of this data release is to provide the original data, analysis methods, and nitrogen loading models in support of a study of the upper South Platte River annual total nitrogen loads attributed to atmospheric deposition of reactive nitrogen during 2017-2018. The data release includes water-quality and stream discharge data and associated predictive regression models used in the estimat
U.S. Geological Survey Precipitation Chemistry Quality Assurance Project Data 2017 - 2018
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: 41
External quality-assurance project report for the National Atmospheric Deposition Program National Trends Network and Mercury Deposition Network, 2021–22
The U.S. Geological Survey Precipitation Chemistry Quality Assurance project (PCQA) operated five distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program (NADP) National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2021–22. The NTN programs included (1) a field audit program to evaluate sample contamination and stabilit
Authors
Noel A. Deyette, Gregory A. Wetherbee, RoseAnn Martin
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, M. 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 and Products
U.S. Geological Survey Precipitation Chemistry Quality Assurance Project Data 2021 – 2022
The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) was initiated in 1978 by the Association of State Agricultural Experiment Stations to monitor long-term atmospheric chemistry and the effects pollutants have on aquatic and terrestrial systems. As of fall 2023, precipitation was being collected at approximately 260 NTN sites in the United States, including Puerto Rico a
National Atmospheric Deposition Program Pollen Study Data for 2021 Pollen Season
Pollen was measured in ambient air by several methods and in wet atmospheric deposition samples at three monitoring sites in the National Atmospheric Deposition Program (NADP) National Trends Network. A method for counting pollen on filters was developed and provided pollen counts for NADP atmospheric wet-deposition samples and high-volume ambient air samplers (HVAS) for comparison with co-located
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
Chemical analyses and precipitation depth data for wet deposition samples collected as part of the National Atmospheric Deposition Program in the Colorado Front Range, 2017-2019
The USGS Precipitation Chemistry Quality Assurance Project (PCQA) conducts research using the infrastructure of the National Atmospheric Deposition Program (NADP) National Trends Network (NTN). Beginning in December 2016, the PCQA installed and began operating NTN monitoring sites in the Denver-Boulder metropolitan area to study urban reactive nitrogen wet deposition. Precipitation depth data are
Water-quality and stream discharge data for estimation of nitrogen loads in the South Platte River, Denver, CO, 2017-2018
The purpose of this data release is to provide the original data, analysis methods, and nitrogen loading models in support of a study of the upper South Platte River annual total nitrogen loads attributed to atmospheric deposition of reactive nitrogen during 2017-2018. The data release includes water-quality and stream discharge data and associated predictive regression models used in the estimat
U.S. Geological Survey Precipitation Chemistry Quality Assurance Project Data 2017 - 2018
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: 41
External quality-assurance project report for the National Atmospheric Deposition Program National Trends Network and Mercury Deposition Network, 2021–22
The U.S. Geological Survey Precipitation Chemistry Quality Assurance project (PCQA) operated five distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program (NADP) National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2021–22. The NTN programs included (1) a field audit program to evaluate sample contamination and stabilit
Authors
Noel A. Deyette, Gregory A. Wetherbee, RoseAnn Martin
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, M. 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