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Daniels J, Liang L, Benedict KB, Brahney J, Rangel R, Weathers KC, Ponette-González AG. Satellite-based aerosol optical depth estimates over the continental U.S. during the 2020 wildfire season: Roles of smoke and land cover. Sci Total Environ 2024; 921:171122. [PMID: 38395165 DOI: 10.1016/j.scitotenv.2024.171122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 02/25/2024]
Abstract
Wildfires produce smoke that can affect an area >1000 times the burn extent, with far-reaching human health, ecologic, and economic impacts. Accurately estimating aerosol load within smoke plumes is therefore crucial for understanding and mitigating these impacts. We evaluated the effectiveness of the latest Collection 6.1 MODIS Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm in estimating aerosol optical depth (AOD) across the U.S. during the historic 2020 wildfire season. We compared satellite-based MAIAC AOD to ground-based AERONET AOD measurements during no-, light-, medium-, and heavy-smoke conditions identified using the Hazard Mapping System Fire and Smoke Product. This smoke product consists of maximum extent smoke polygons digitized by analysts using visible band imagery and classified according to smoke density. We also examined the strength of the correlations between satellite- and ground-based AOD for major land cover types under various smoke density levels. MAIAC performed well in estimating AOD during smoke-affected conditions. Correlations between MAIAC and AERONET AOD were strong for medium- (r = 0.91) and heavy-smoke (r = 0.90) density, and MAIAC estimates of AOD showed little bias relative to ground-based AERONET measurements (normalized mean bias = 3 % for medium, 5 % for heavy smoke). During two high AOD, heavy smoke episodes, MAIAC underestimated ground-based AERONET AOD under mixed aerosol (i.e., smoke and dust; median bias = -0.08) and overestimated AOD under smoke-dominated (median bias = 0.02) aerosol. MAIAC most overestimated ground-based AERONET AOD over barren land (mean NMB = 48 %). Our findings indicate that MODIS MAIAC can provide robust estimates of AOD as smoke density increases in coming years. Increased frequency of mixed aerosol and expansion of developed land could affect the performance of the MAIAC algorithm in the future, however, with implications for evaluating wildfire-associated health and welfare effects and air quality standards.
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Affiliation(s)
- Jacob Daniels
- Department of Electrical Engineering, University of North Texas, 1155 Union Circle #305279, Denton, TX 76203, USA
| | - Lu Liang
- Department of Geography and the Environment, University of North Texas, 1155 Union Circle #305279, Denton, TX 76203, USA
| | - Katherine B Benedict
- Earth and Environmental Science Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Janice Brahney
- Department of Watershed Sciences and Ecology Center, Utah State University, 5210 Old Main Hill, Logan, UT 84322, USA
| | - Roman Rangel
- Department of Geography and the Environment, University of North Texas, 1155 Union Circle #305279, Denton, TX 76203, USA
| | | | - Alexandra G Ponette-González
- Natural History Museum of Utah, University of Utah, 301 Wakara Way, Salt Lake City, UT 84108, USA; Department of City and Metropolitan Planning, University of Utah, 375 South 1530 East, Suite 220, Salt Lake City, UT 84112, USA.
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2
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Pan D, Pollack IB, Sive BC, Marsavin A, Naimie LE, Benedict KB, Zhou Y, Sullivan AP, Prenni AJ, Cope EJ, Juncosa Calahorrano JF, Fischer EV, Schichtel BA, Collett JL. Source characterization of volatile organic compounds at Carlsbad Caverns National Park. J Air Waste Manag Assoc 2023; 73:914-929. [PMID: 37850691 DOI: 10.1080/10962247.2023.2266696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/25/2023] [Indexed: 10/19/2023]
Abstract
Carlsbad Caverns National Park (CAVE), located in southeastern New Mexico, experiences elevated ground-level ozone (O3) exceeding the National Ambient Air Quality Standard (NAAQS) of 70 ppbv. It is situated adjacent to the Permian Basin, one of the largest oil and gas (O&G) producing regions in the US. In 2019, the Carlsbad Caverns Air Quality Study (CarCavAQS) was conducted to examine impacts of different sources on ozone precursors, including nitrogen oxides (NOx) and volatile organic compounds (VOCs). Here, we use positive matrix factorization (PMF) analysis of speciated VOCs to characterize VOC sources at CAVE during the study. Seven factors were identified. Three factors composed largely of alkanes and aromatics with different lifetimes were attributed to O&G development and production activities. VOCs in these factors were typical of those emitted by O&G operations. Associated residence time analyses (RTA) indicated their contributions increased in the park during periods of transport from the Permian Basin. These O&G factors were the largest contributor to VOC reactivity with hydroxyl radicals (62%). Two PMF factors were rich in photochemically generated secondary VOCs; one factor contained species with shorter atmospheric lifetimes and one with species with longer lifetimes. RTA of the secondary factors suggested impacts of O&G emissions from regions farther upwind, such as Eagle Ford Shale and Barnett Shale formations. The last two factors were attributed to alkenes likely emitted from vehicles or other combustion sources in the Permian Basin and regional background VOCs, respectively.Implications: Carlsbad Caverns National Park experiences ground-level ozone exceeding the National Ambient Air Quality Standard. Volatile organic compounds are critical precursors to ozone formation. Measurements in the Park identify oil and gas production and development activities as the major contributors to volatile organic compounds. Emissions from the adjacent Permian Basin contributed to increases in primary species that enhanced local ozone formation. Observations of photochemically generated compounds indicate that ozone was also transported from shale formations and basins farther upwind. Therefore, emission reductions of volatile organic compounds from oil and gas activities are important for mitigating elevated O3 in the region.
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Affiliation(s)
- Da Pan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Ilana B Pollack
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Barkley C Sive
- National Park Service, Air Resources Division, Lakewood, CO, USA
| | - Andrey Marsavin
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Lillian E Naimie
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Katherine B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Yong Zhou
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Amy P Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Anthony J Prenni
- National Park Service, Air Resources Division, Lakewood, CO, USA
- Cooperative Institute for Research in the Atmosphere (CIRA), Colorado State University, Fort Collins, CO, USA
| | - Elana J Cope
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | | | - Emily V Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Bret A Schichtel
- National Park Service, Air Resources Division, Lakewood, CO, USA
- Cooperative Institute for Research in the Atmosphere (CIRA), Colorado State University, Fort Collins, CO, USA
| | - Jeffrey L Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
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3
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Pollack IB, Pan D, Marsavin A, Cope EJ, Juncosa Calahorrano J, Naimie L, Benedict KB, Sullivan AP, Zhou Y, Sive BC, Prenni AJ, Schichtel BA, Collett J, Fischer EV. Observations of ozone, acyl peroxy nitrates, and their precursors during summer 2019 at Carlsbad Caverns National Park, New Mexico. J Air Waste Manag Assoc 2023; 73:951-968. [PMID: 37850745 DOI: 10.1080/10962247.2023.2271436] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/25/2023] [Indexed: 10/19/2023]
Abstract
Carlsbad Caverns National Park (CAVE) is located in southeastern New Mexico and is adjacent to the Permian Basin, one of the most productive oil and natural gas (O&G) production regions in the United States. Since 2018, ozone (O3) at CAVE has frequently exceeded the 70 ppbv 8-hour National Ambient Air Quality Standard. We examine the influence of regional emissions on O3 formation using observations of O3, nitrogen oxides (NOx = NO + NO2), a suite of volatile organic compounds (VOCs), peroxyacetyl nitrate (PAN), and peroxypropionyl nitrate (PPN). Elevated O3 and its precursors are observed when the wind is from the southeast, the direction of the Permian Basin. We identify 13 days during the July 25 to September 5, 2019 study period when the maximum daily 8-hour average (MDA8) O3 exceeded 65 ppbv; MDA8 O3 exceeded 70 ppbv on 5 of these days. The results of a positive matrix factorization (PMF) analysis are used to identify and attribute source contributions of VOCs and NOx. On days when the winds are from the southeast, there are larger contributions from factors associated with primary O&G emissions; and, on high O3 days, there is more contribution from factors associated with secondary photochemical processing of O&G emissions. The observed ratio of VOCs to NOx is consistently high throughout the study period, consistent with NOx-limited O3 production. Finally, all high O3 days coincide with elevated acyl peroxy nitrate abundances with PPN to PAN ratios > 0.15 ppbv ppbv-1 indicating that anthropogenic VOC precursors, and often alkanes specifically, dominate the photochemistry.Implications: The results above strongly indicate NOx-sensitive photochemistry at Carlsbad Caverns National Park indicating that reductions in NOx emissions should drive reductions in O3. However, the NOx-sensitivity is largely driven by emissions of NOx into a VOC-rich environment, and a high PPN:PAN ratio and its relationship to O3 indicate substantial influence from alkanes in the regional photochemistry. Thus, simultaneous reductions in emissions of NOx and non-methane VOCs from the oil and gas sector should be considered for reducing O3 at Carlsbad Caverns National Park. Reductions in non-methane VOCs will have the added benefit of reducing formation of other secondary pollutants and air toxics.
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Affiliation(s)
- Ilana B Pollack
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Da Pan
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Andrey Marsavin
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Elana J Cope
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
- Department of Chemistry, University of Oregon, Eugene, Oregon, USA
| | | | - L Naimie
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - K B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
- Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - Amy P Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Y Zhou
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - B C Sive
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
| | - Anthony J Prenni
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado, USA
| | - Bret A Schichtel
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado, USA
| | - Jeffrey Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Emily V Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
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4
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Naimie LE, Sullivan AP, Benedict KB, Prenni AJ, Sive BC, Schichtel BA, Fischer EV, Pollack I, Collett J. PM 2.5 in Carlsbad Caverns National Park: Composition, sources, and visibility impacts. J Air Waste Manag Assoc 2022; 72:1201-1218. [PMID: 35605169 DOI: 10.1080/10962247.2022.2081634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Carlsbad Caverns National Park in southeastern New Mexico is adjacent to the Permian Basin, one of the most productive oil and gas regions in the country. The 2019 Carlsbad Caverns Air Quality Study (CarCavAQS) was designed to examine the influence of regional sources, including urban emissions, oil and gas development, wildfires, and soil dust on air quality in the park. Field measurements of aerosols, trace gases, and deposition were conducted from 25 July through 5 September 2019. Here, we focus on observations of fine particles and key trace gas precursors to understand the important contributing species and their sources and associated impacts on haze. Key gases measured included aerosol precursors, nitric acid and ammonia, and oil and gas tracer, methane. High-time resolution (6-min) PM2.5 mass ranged up to 31.8 µg m-3, with an average of 7.67 µg m-3. The main inorganic ion contributors were sulfate (avg 1.3 µg m-3), ammonium (0.30 µg m-3), calcium (Ca2+) (0.22 µg m-3), nitrate (0.16 µg m-3), and sodium (0.057 µg m-3). The WSOC concentration averaged 1.2 µg C m-3. Sharp spikes were observed in Ca2+, consistent with local dust generation and transport. Ion balance analysis and abundant nitric acid suggest PM2.5 nitrate often reflected reaction between nitric acid and sea salt, forming sodium nitrate, and between nitric acid and soil dust containing calcium carbonate, forming calcium nitrate. Sulfate and soil dust are the major contributors to modeled light extinction in the 24-hr average daily IMPROVE observations. Higher time resolution data revealed a maximum 1-hr extinction value of 90 Mm-1 (excluding coarse aerosol) and included periods of significant light extinction from BC as well as sulfate and soil dust. Residence time analysis indicated enrichment of sulfate, BC, and methane during periods of transport from the southeast, the direction of greatest abundance of oil and gas development.Implications: Rapid development of U.S. oil and gas resources raises concerns about potential impacts on air quality in National Parks. Measurements in Carlsbad Caverns National Park provide new insight into impacts of unconventional oil and gas development and other sources on visual air quality in the park. Major contributors to visibility impairment include sulfate, soil dust (often reacted with nitric acid), and black carbon. The worst periods of visibility and highest concentrations of many aerosol components were observed during transport from the southeast, a region of dense Permian Basin oil and gas development.
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Affiliation(s)
- Lillian E Naimie
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Amy P Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - K B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Anthony J Prenni
- National Park Service Air Resource Division, Lakewood, CO, USA
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, USA
| | - B C Sive
- National Park Service Air Resource Division, Lakewood, CO, USA
| | - Bret A Schichtel
- National Park Service Air Resource Division, Lakewood, CO, USA
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, USA
| | - Emily V Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Ilana Pollack
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Jeffrey Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
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5
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Prenni AJ, Benedict KB, Day DE, Sive BC, Zhou Y, Naimie L, Gebhart KA, Dombek T, De Boskey M, Hyslop NP, Spencer E, Chew QM, Collett JL, Schichtel BA. Wintertime haze and ozone at Dinosaur National Monument. J Air Waste Manag Assoc 2022; 72:951-968. [PMID: 35254216 DOI: 10.1080/10962247.2022.2048922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/19/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Dinosaur National Monument (DINO) is located near the northeastern edge of the Uinta Basin and often experiences elevated levels of wintertime ground-level ozone. Previous studies have shown that high ozone mixing ratios in the Uinta Basin are driven by elevated levels of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from regional oil and gas development coupled with temperature inversions and enhanced photochemistry from persistent snow cover. Here, we show that persistent snow cover and temperature inversions, along with abundant ammonia, also lead to wintertime haze in this region. A study was conducted at DINO from November 2018 through May 2020 where ozone, speciated fine and coarse aerosols, inorganic gases, and VOCs were measured. Three National Ambient Air Quality Standards (NAAQS) ozone exceedances were observed in the first winter, and no exceedances were observed in the second winter. In contrast, elevated levels of particulate matter were observed both winters, with 24-h averaged particle light extinction exceeding 100 Mm-1. These haze events were dominated by ammonium nitrate, and particulate organics were highly correlated with ammonium nitrate. Ammonium nitrate formation was limited by nitric acid in winter. As such, reductions in regional NOx emissions should reduce haze levels and improve visibility at DINO in winter. Long-term measurements of particulate matter from nearby Vernal, Utah, suggest that visibility impairment is a persistent issue in the Uinta Basin in winter. From April through October 2019, relatively clean conditions occurred, with average particle extinction of ~10 Mm-1. During this period, ammonium nitrate concentrations were lower by more than an order of magnitude, and contributions from coarse mass and soil to haze levels increased. VOC markers indicated that the high levels of observed pollutants in winter were likely from local sources related to oil and gas extraction activities.Implications: Elevated ground-level ozone and haze levels were observed at Dinosaur National Monument in winter. Haze episodes were dominated by ammonium nitrate, with 24-h averaged particle light extinction exceeding 100 Mm-1, reducing visual range near the surface to ~35 km. Despite elevated ammonium nitrate concentrations, additional gas-phase ammonia was available, such that any increase in NOx emissions in the region is likely to lead to even greater haze levels.
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Affiliation(s)
- Anthony J Prenni
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
| | - Katherine B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Derek E Day
- Cooperative Institute for Research in the Atmosphere (CIRA), Colorado State University, Fort Collins, Colorado, USA
| | - Barkley C Sive
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
| | - Yong Zhou
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Lilly Naimie
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Kristi A Gebhart
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
| | - Tracy Dombek
- Analytical Sciences, RTI International, Research Triangle Park, North Carolina, USA
| | - Miranda De Boskey
- Analytical Sciences, RTI International, Research Triangle Park, North Carolina, USA
| | - Nicole P Hyslop
- University of California, Davis, Air Quality Research Center, Davis, California, USA
| | | | | | - Jeffrey L Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
| | - Bret A Schichtel
- National Park Service, Air Resources Division, Lakewood, Colorado, USA
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Gorkowski K, Benedict KB, Carrico CM, Dubey MK. Complexities in Modeling Organic Aerosol Light Absorption. J Phys Chem A 2022; 126:4827-4833. [PMID: 35834798 PMCID: PMC9340763 DOI: 10.1021/acs.jpca.2c02236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 07/04/2022] [Indexed: 11/29/2022]
Abstract
Aerosol particles dynamically evolve in the atmosphere by physicochemical interactions with sunlight, trace chemical species, and water. Current modeling approaches fix properties such as aerosol refractive index, introducing spatial and temporal errors in the radiative impacts. Further progress requires a process-level description of the refractive indices as the particles age and experience physicochemical transformations. We present two multivariate modeling approaches of light absorption by brown carbon (BrC). The initial approach was to extend the modeling framework of the refractive index at 589 nm (nD), but that result was insufficient. We developed a second multivariate model using aromatic rings and functional groups to predict the imaginary part of the complex refractive index. This second model agreed better with measured spectral absorption peaks, showing promise for a simplified treatment of BrC optics. In addition to absorption, organic functionalities also alter the water affinity of the molecules, leading to a hygroscopic uptake and increased light absorption, which we show through measurements and modeling.
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Affiliation(s)
- Kyle Gorkowski
- Earth
and Environmental Science, Los Alamos National
Laboratory, Los Alamos, New Mexico 87545, United States
| | - Katherine B. Benedict
- Earth
and Environmental Science, Los Alamos National
Laboratory, Los Alamos, New Mexico 87545, United States
| | - Christian M. Carrico
- New
Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, United States
| | - Manvendra K. Dubey
- Earth
and Environmental Science, Los Alamos National
Laboratory, Los Alamos, New Mexico 87545, United States
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Pan D, Benedict KB, Golston LM, Wang R, Collett JL, Tao L, Sun K, Guo X, Ham J, Prenni AJ, Schichtel BA, Mikoviny T, Müller M, Wisthaler A, Zondlo MA. Ammonia Dry Deposition in an Alpine Ecosystem Traced to Agricultural Emission Hotpots. Environ Sci Technol 2021; 55:7776-7785. [PMID: 34061518 DOI: 10.1021/acs.est.0c05749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Elevated reactive nitrogen (Nr) deposition is a concern for alpine ecosystems, and dry NH3 deposition is a key contributor. Understanding how emission hotspots impact downwind ecosystems through dry NH3 deposition provides opportunities for effective mitigation. However, direct NH3 flux measurements with sufficient temporal resolution to quantify such events are rare. Here, we measured NH3 fluxes at Rocky Mountain National Park (RMNP) during two summers and analyzed transport events from upwind agricultural and urban sources in northeastern Colorado. We deployed open-path NH3 sensors on a mobile laboratory and an eddy covariance tower to measure NH3 concentrations and fluxes. Our spatial sampling illustrated an upslope event that transported NH3 emissions from the hotspot to RMNP. Observed NH3 deposition was significantly higher when backtrajectories passed through only the agricultural region (7.9 ng m-2 s-1) versus only the urban area (1.0 ng m-2 s-1) and both urban and agricultural areas (2.7 ng m-2 s-1). Cumulative NH3 fluxes were calculated using observed, bidirectional modeled, and gap-filled fluxes. More than 40% of the total dry NH3 deposition occurred when air masses were traced back to agricultural source regions. More generally, we identified that 10 (25) more national parks in the U.S. are within 100 (200) km of an NH3 hotspot, and more observations are needed to quantify the impacts of these hotspots on dry NH3 deposition in these regions.
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Affiliation(s)
- Da Pan
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
| | - Katherine B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Levi M Golston
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
| | - Rui Wang
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
| | - Jeffrey L Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Lei Tao
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
| | - Kang Sun
- Department of Civil, Structural and Environmental Engineering, University at Buffalo, Buffalo, New York 14260, United States
- Research and Education in Energy, Environment and Water (RENEW) Institute, University at Buffalo, Buffalo, New York 14260, United States
| | - Xuehui Guo
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
| | - Jay Ham
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado 80521, United States
| | - Anthony J Prenni
- Air Resources Division, National Park Service, Lakewood, Colorado 80235, United States
| | - Bret A Schichtel
- Air Resources Division, National Park Service, Fort Collins, Colorado 80525, United States
| | - Tomas Mikoviny
- Chemistry and Dynamics Branch, Science Directorate, NASA Langley Research Center, Hampton, Virginia 23666, United States
- Oak Ridge Associated Universities, Oak Ridge, Tennessee 37830, United States
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
| | - Markus Müller
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck 6020, Austria
| | - Armin Wisthaler
- Department of Chemistry, University of Oslo, Oslo 0315, Norway
- Institute for Ion Physics and Applied Physics, University of Innsbruck, Innsbruck 6020, Austria
| | - Mark A Zondlo
- Department of Civil and Environmental Engineering, Princeton University, Princeton 08544, New Jersey, United States
- Center for Mid-Infrared Technologies for Health and the Environmental, NSF-ERC, Princeton, New Jersey 08540, United States
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Zhang Y, Benedict KB, Tang A, Sun Y, Fang Y, Liu X. Persistent Nonagricultural and Periodic Agricultural Emissions Dominate Sources of Ammonia in Urban Beijing: Evidence from 15N Stable Isotope in Vertical Profiles. Environ Sci Technol 2020; 54:102-109. [PMID: 31818095 DOI: 10.1021/acs.est.9b05741] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Ammonia (NH3) emission reduction is key to limiting the deadly PM2.5 pollution globally. However, studies of long-term source apportionment of vertical NH3 are relatively limited. On the basis of the one-year measurements of weekly vertical profiles of δ15N-NH3 at 5 heights (2, 15, 102, 180, and 320 m) on a 325-m meteorological tower in urban Beijing, we found that vertical profiles of NH3 concentrations generally remained stable with height. δ15N-NH3 increased obviously as a function of height in cold seasons (with heating) and decreased in warm seasons (with fertilization), indicating a stronger human-induced seasonal variation via regional transport at higher altitudes. Relatively stable δ15N-NH3 near the ground surface suggested the strong local emission. The results of isotopic mixing model (SIAR) indicate that source apportionment using measured δ15N-NH3 only would overestimate the contribution of agricultural emissions to NH3. By using an estimation of initial δ15N-NH3, we found that nonagricultural sources contributed ∼72% of NH3 on average. Our study suggests that (i) both persistent nonagricultural and periodic agricultural emissions drive atmospheric NH3 concentration and its vertical distribution in urban Beijing; and (ii) source apportionment based on measured δ15N-NH3 only likely underestimates fossil fuel source contribution, if the combined NHx isotope effects are not considered.
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Affiliation(s)
- Yangyang Zhang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P. R. China
| | - Katherine B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Aohan Tang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P. R. China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Yunting Fang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110164, P. R. China
| | - Xuejun Liu
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P. R. China
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Walker JT, Beachley G, Zhang L, Benedict KB, Sive BC, Schwede DB. A review of measurements of air-surface exchange of reactive nitrogen in natural ecosystems across North America. Sci Total Environ 2020; 698:133975. [PMID: 31499348 PMCID: PMC7032654 DOI: 10.1016/j.scitotenv.2019.133975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 04/13/2023]
Abstract
This review summarizes the state of the science of measurements of dry deposition of reactive nitrogen (Nr) compounds in North America, beginning with current understanding of the importance of dry deposition at the U.S. continental scale followed by a review of micrometeorological flux measurement methods. Measurements of Nr air-surface exchange in natural ecosystems of North America are then summarized, focusing on the U.S. and Canada. Drawing on this synthesis, research needed to address the incompleteness of dry deposition budgets, more fully characterize temporal and geographical variability of fluxes, and better understand air-surface exchange processes is identified. Our assessment points to several data and knowledge gaps that must be addressed to advance dry deposition budgets and air-surface exchange modeling for North American ecosystems. For example, recent studies of particulate (NO3-) and gaseous (NOx, HONO, peroxy nitrates) oxidized N fluxes challenge the fundamental framework of unidirectional flux from the atmosphere to the surface employed in most deposition models. Measurements in forest ecosystems document the importance of in-canopy chemical processes in regulating the net flux between the atmosphere and biosphere, which can result in net loss from the canopy. These results emphasize the need for studies to quantify within- and near-canopy sources and sinks of the full suite of components of the Nr chemical system under study (e.g., NOy or HNO3-NH3-NH4NO3). With respect to specific ecosystems and geographical locations, additional flux measurements are needed particularly in agricultural regions (NH3), coastal zones (NO3- and organic N), and arid ecosystems and along urban to rural gradients (NO2). Measurements that investigate non-stomatal exchange processes (e.g., deposition to wet surfaces) and the biogeochemical drivers of bidirectional exchange (e.g., NH3) are considered high priority. Establishment of long-term sites for process level measurements of reactive chemical fluxes should be viewed as a high priority long-term endeavor of the atmospheric chemistry and ecological communities.
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Affiliation(s)
- John T Walker
- U.S. EPA, Office of Research and Development, Durham, NC, USA.
| | | | - Leiming Zhang
- Environment and Climate Change Canada, Toronto, Ontario, Canada
| | - Katherine B Benedict
- Colorado State University, Department of Atmospheric Science, Fort Collins, CO, USA
| | - Barkley C Sive
- National Park Service, Air Resources Division, Lakewood, CO, USA
| | - Donna B Schwede
- U.S. EPA, Office of Research and Development, Durham, NC, USA
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Wetherbee GA, Benedict KB, Murphy SF, Elliott EM. Inorganic nitrogen wet deposition gradients in the Denver-Boulder metropolitan area and Colorado Front Range - Preliminary implications for Rocky Mountain National Park and interpolated deposition maps. Sci Total Environ 2019; 691:1027-1042. [PMID: 31326795 DOI: 10.1016/j.scitotenv.2019.06.528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 06/10/2023]
Abstract
For the first time in the 40-year history of the National Atmospheric Deposition Program/National Trends Network (NADP/NTN), a unique urban-to-rural transect of wet deposition monitoring stations was operated as part of the NTN in 2017 to quantify reactive inorganic nitrogen wet deposition for adjacent urban and rural, montane regions. The transect of NADP stations (sites) was used to collect continuous precipitation depth and weekly wet-deposition samples in the Denver - Boulder, Colorado, urban corridor. Gradients in reactive inorganic nitrogen (Nr) concentrations and wet deposition were identified along the transect, which included Rocky Mountain National Park. Back trajectory modeling and stable isotopes suggested contribution of agricultural ammonia (NH3) to urban Nr wet deposition in Denver, but apportionment of wet-deposited Nr to agricultural versus urban mobile sources was not possible for this study. The results demonstrate the importance of multiple monitoring sites across an urban area in defining fine-scale geographic patterns in atmospheric deposition and its sources. Data from new sites located within 50 km of the urban area demonstrate that the urban influence does not extend as far as the inverse distance weighting would have suggested without such empirical monitoring data. It is important to determine the radius of influence of urban emissions and associated deposition on the interpolated deposition raster, which is constrained by a paucity of monitoring sites east of Denver.
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Walker JT, Beachley G, Amos HM, Baron JS, Bash J, Baumgardner R, Bell MD, Benedict KB, Chen X, Clow DW, Cole A, Coughlin JG, Cruz K, Daly RW, Decina SM, Elliott EM, Fenn ME, Ganzeveld L, Gebhart K, Isil SS, Kerschner BM, Larson RS, Lavery T, Lear GG, Macy T, Mast MA, Mishoe K, Morris KH, Padgett PE, Pouyat RV, Puchalski M, Pye HOT, Rea AW, Rhodes MF, Rogers CM, Saylor R, Scheffe R, Schichtel BA, Schwede DB, Sexstone GA, Sive BC, Sosa Echeverría R, Templer PH, Thompson T, Tong D, Wetherbee GA, Whitlow TH, Wu Z, Yu Z, Zhang L. Toward the improvement of total nitrogen deposition budgets in the United States. Sci Total Environ 2019; 691:1328-1352. [PMID: 31466212 PMCID: PMC7724633 DOI: 10.1016/j.scitotenv.2019.07.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 07/02/2019] [Accepted: 07/04/2019] [Indexed: 06/10/2023]
Abstract
Frameworks for limiting ecosystem exposure to excess nutrients and acidity require accurate and complete deposition budgets of reactive nitrogen (Nr). While much progress has been made in developing total Nr deposition budgets for the U.S., current budgets remain limited by key data and knowledge gaps. Analysis of National Atmospheric Deposition Program Total Deposition (NADP/TDep) data illustrates several aspects of current Nr deposition that motivate additional research. Averaged across the continental U.S., dry deposition contributes slightly more (55%) to total deposition than wet deposition and is the dominant process (>90%) over broad areas of the Southwest and other arid regions of the West. Lack of dry deposition measurements imposes a reliance on models, resulting in a much higher degree of uncertainty relative to wet deposition which is routinely measured. As nitrogen oxide (NOx) emissions continue to decline, reduced forms of inorganic nitrogen (NHx = NH3 + NH4+) now contribute >50% of total Nr deposition over large areas of the U.S. Expanded monitoring and additional process-level research are needed to better understand NHx deposition, its contribution to total Nr deposition budgets, and the processes by which reduced N deposits to ecosystems. Urban and suburban areas are hotspots where routine monitoring of oxidized and reduced Nr deposition is needed. Finally, deposition budgets have incomplete information about the speciation of atmospheric nitrogen; monitoring networks do not capture important forms of Nr such as organic nitrogen. Building on these themes, we detail the state of the science of Nr deposition budgets in the U.S. and highlight research priorities to improve deposition budgets in terms of monitoring and flux measurements, leaf- to regional-scale modeling, source apportionment, and characterization of deposition trends and patterns.
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Affiliation(s)
- J T Walker
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America.
| | - G Beachley
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC, United States of America
| | - H M Amos
- AAAS Science and Technology Policy Fellow hosted by the U.S. Environmental Protection Agency, Office of Research and Development, Washington, DC, United States of America
| | - J S Baron
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, CO, United States of America
| | - J Bash
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - R Baumgardner
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - M D Bell
- National Park Service, Air Resources Division, Lakewood, CO, United States of America
| | - K B Benedict
- Colorado State University, Department of Atmospheric Science, Fort Collins, CO, United States of America
| | - X Chen
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - D W Clow
- U.S. Geological Survey, Colorado Water Science Center, Denver, CO, United States of America
| | - A Cole
- Environment and Climate Change Canada, Air Quality Research Division, Toronto, ON, Canada
| | - J G Coughlin
- U.S. Environmental Protection Agency, Region 5, Chicago, IL, United States of America
| | - K Cruz
- U.S. Department of Agriculture, National Institute of Food and Agriculture, Washington, DC, United States of America
| | - R W Daly
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - S M Decina
- University of California, Department of Chemistry, Berkeley, CA, United States of America
| | - E M Elliott
- University of Pittsburgh, Department of Geology & Environmental Science, Pittsburgh, PA, United States of America
| | - M E Fenn
- U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, Riverside, CA, United States of America
| | - L Ganzeveld
- Meteorology and Air Quality (MAQ), Wageningen University and Research Centre, Wageningen, Netherlands
| | - K Gebhart
- National Park Service, Air Resources Division, Fort Collins, CO, United States of America
| | - S S Isil
- Wood Environment & Infrastructure Solutions, Inc., Newberry, FL, United States of America
| | - B M Kerschner
- Prairie Research Institute, University of Illinois, Champaign, IL, United States of America
| | - R S Larson
- Wisconsin State Laboratory of Hygiene, University of Wisconsin, Madison, WI, United States of America
| | - T Lavery
- Environmental Consultant, Cranston, RI, United States of America
| | - G G Lear
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC, United States of America
| | - T Macy
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC, United States of America
| | - M A Mast
- U.S. Geological Survey, Colorado Water Science Center, Denver, CO, United States of America
| | - K Mishoe
- Wood Environment & Infrastructure Solutions, Inc., Newberry, FL, United States of America
| | - K H Morris
- National Park Service, Air Resources Division, Lakewood, CO, United States of America
| | - P E Padgett
- U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, Riverside, CA, United States of America
| | - R V Pouyat
- U.S. Forest Service, Bethesda, MD, United States of America
| | - M Puchalski
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC, United States of America
| | - H O T Pye
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - A W Rea
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - M F Rhodes
- D&E Technical, Urbana, IL, United States of America
| | - C M Rogers
- Wood Environment & Infrastructure Solutions, Inc., Newberry, FL, United States of America
| | - R Saylor
- National Oceanic and Atmospheric Administration, Air Resources Laboratory, Oak Ridge, TN, United States of America
| | - R Scheffe
- U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Durham, NC, United States of America
| | - B A Schichtel
- National Park Service, Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO, United States of America
| | - D B Schwede
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - G A Sexstone
- U.S. Geological Survey, Colorado Water Science Center, Denver, CO, United States of America
| | - B C Sive
- National Park Service, Air Resources Division, Lakewood, CO, United States of America
| | - R Sosa Echeverría
- Centro de Ciencias de la Atmosfera, Universidad Nacional Autónoma de México, Mexico
| | - P H Templer
- Boston University, Department of Biology, Boston, MA, United States of America
| | - T Thompson
- AAAS Science and Technology Policy Fellow hosted by the U.S. Environmental Protection Agency, Office of Policy, Washington, DC, United States of America
| | - D Tong
- George Mason University. National Oceanic and Atmospheric Administration, Air Resources Laboratory, College Park, MD, United States of America
| | - G A Wetherbee
- U.S. Geological Survey, Hydrologic Networks Branch, Denver, CO, United States of America
| | - T H Whitlow
- Cornell University, Department of Horticulture, Ithaca, NY, United States of America
| | - Z Wu
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, United States of America
| | - Z Yu
- University of Pittsburgh, Department of Geology & Environmental Science, Pittsburgh, PA, United States of America
| | - L Zhang
- Environment and Climate Change Canada, Air Quality Research Division, Toronto, ON, Canada
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Puchalski MA, Walker JT, Beachley GM, Zondlo MA, Benedict KB, Grant RH, Schichtel BA, Rogers CM, Leytem AB, Rice J, Morris K, Schauer JJ, Wang R. Need for Improved Monitoring of Spatial and Temporal Trends of Reduced Nitrogen. EM (Pittsburgh Pa) 2019; 2019:https://www.awma.org/content.asp?admin=Y&contentid=528. [PMID: 36960194 PMCID: PMC10032039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Affiliation(s)
- Melissa A. Puchalski
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC
- Corresponding author: Melissa Puchalski,
| | - John T. Walker
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC
| | - Gregory M. Beachley
- U.S. Environmental Protection Agency, Office of Air and Radiation, Washington, DC
| | - Mark A. Zondlo
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ
| | | | | | - Bret A. Schichtel
- National Park Service, Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, CO
| | | | - April B. Leytem
- U.S. Department of Agriculture, Agricultural Research Service, Kimberly, ID
| | - Joann Rice
- U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Durham, NC
| | - Kristi Morris
- National Park Service, Air Resources Division, Lakewood, CO
| | - James J. Schauer
- Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, Madison, WI
| | - Rui Wang
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ
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Benedict KB, Prenni AJ, Sullivan AP, Evanoski-Cole AR, Fischer EV, Callahan S, Sive BC, Zhou Y, Schichtel BA, Collett Jr JL. Impact of Front Range sources on reactive nitrogen concentrations and deposition in Rocky Mountain National Park. PeerJ 2018; 6:e4759. [PMID: 29780668 PMCID: PMC5958887 DOI: 10.7717/peerj.4759] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 04/23/2018] [Indexed: 11/20/2022] Open
Abstract
Human influenced atmospheric reactive nitrogen (RN) is impacting ecosystems in Rocky Mountain National Park (ROMO). Due to ROMO's protected status as a Class 1 area, these changes are concerning, and improving our understanding of the contributions of different types of RN and their sources is important for reducing impacts in ROMO. In July-August 2014 the most comprehensive measurements (to date) of RN were made in ROMO during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ). Measurements included peroxyacetyl nitrate (PAN), C1-C5 alkyl nitrates, and high-time resolution NOx, NOy, and ammonia. A limited set of measurements was extended through October. Co-located measurements of a suite of volatile organic compounds provide information on source types impacting ROMO. Specifically, we use ethane as a tracer of oil and gas operations and tetrachloroethylene (C2Cl4) as an urban tracer to investigate their relationship with RN species and transport patterns. Results of this analysis suggest elevated RN concentrations are associated with emissions from oil and gas operations, which are frequently co-located with agricultural production and livestock feeding areas in the region, and from urban areas. There also are periods where RN at ROMO is impacted by long-range transport. We present an atmospheric RN budget and a nitrogen deposition budget with dry and wet components. Total deposition for the period (7/1-9/30) was estimated at 1.58 kg N/ha, with 87% from wet deposition during this period of above average precipitation. Ammonium wet deposition was the dominant contributor to total nitrogen deposition followed by nitrate wet deposition and total dry deposition. Ammonia was estimated to be the largest contributor to dry deposition followed by nitric acid and PAN (other species included alkyl nitrates, ammonium and nitrate). All three species are challenging to measure routinely, especially at high time resolution.
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Affiliation(s)
- Katherine B. Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Anthony J. Prenni
- Air Resources Division, National Park Service, Lakewood, CO, United States of America
| | - Amy P. Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Ashley R. Evanoski-Cole
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
- Present address: Department of Chemistry, St. Bonaventure University, St. Bonaventure, NY, United States of America
| | - Emily V. Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Sara Callahan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Barkley C. Sive
- Air Resources Division, National Park Service, Lakewood, CO, United States of America
| | - Yong Zhou
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Bret A. Schichtel
- Air Resources Division, National Park Service, Fort Collins, CO, United States of America
| | - Jeffrey L. Collett Jr
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
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14
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Affiliation(s)
- Katherine B. Benedict
- Department of Land, Air,
and Water Resources, University of California—Davis, One Shields Avenue, Davis, California 95616, United States
| | - Cort Anastasio
- Department of Land, Air,
and Water Resources, University of California—Davis, One Shields Avenue, Davis, California 95616, United States
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15
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Abstract
Photolysis of nitrate (NO3-) produces reactive nitrogen and oxygen species via three different channels, forming: (1) nitrogen dioxide (NO2) and hydroxyl radical (•OH), (2) nitrite (NO2-) and oxygen atom (O(3P)), and (3) peroxynitrite (ONOO-). These photoproducts are important oxidants and reactants in surface waters, atmospheric drops, and snowpacks. While the efficiency of the first channel, to form NO2, is well documented, a large range of values have been reported for the second channel, nitrite, above 300 nm. In part, this disagreement reflects secondary chemistry that can produce or destroy nitrite. In this study, we examine factors that influence nitrite production and find that pH, nitrate concentration, and the presence of an •OH scavenger can be important. We measure an average nitrite quantum yield (Φ(NO2-)) of (1.1 ± 0.2)% (313 nm, 50 μM nitrate, pH ≥ 5), which is at the upper end of past measurements and an order of magnitude above the smallest-and most commonly cited-value reported for this channel. Nitrite production is often considered a very minor channel in nitrate photolysis, but our results indicate it is as important as the NO2 channel. In contrast, at 313 nm we observe no formation of peroxynitrite, corresponding to Φ(ONOO-) < 0.26%.
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Affiliation(s)
- Katherine B Benedict
- Department of Land, Air, and Water Resources University of California Davis Davis, California 95616, United States
| | - Alexander S McFall
- Department of Land, Air, and Water Resources University of California Davis Davis, California 95616, United States
| | - Cort Anastasio
- Department of Land, Air, and Water Resources University of California Davis Davis, California 95616, United States
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16
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Malm WC, Schichtel BA, Barna MG, Gebhart KA, Rodriguez MA, Collett JL, Carrico CM, Benedict KB, Prenni AJ, Kreidenweis SM. Aerosol species concentrations and source apportionment of ammonia at Rocky Mountain National Park. J Air Waste Manag Assoc 2013; 63:1245-1263. [PMID: 24344569 DOI: 10.1080/10962247.2013.804466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Changes in ecosystem function at Rocky Mountain National Park (RMNP) are occurring because of emissions of nitrogen and sulfate species along the Front Range of the Colorado Rocky Mountains, as well as sources farther east and west. The nitrogen compounds include both oxidized and reduced nitrogen. A year-long monitoring program of various oxidized and reduced nitrogen species was initiated to better understand their origins as well as the complex chemistry occurring during transport from source to receptor. Specifically the goals of the study were to characterize the atmospheric concentrations of nitrogen species in gaseous, particulate, and aqueous phases (precipitation and clouds) along the east and west sides of the Continental Divide; identify the relative contributions to atmospheric nitrogen species in RMNP from within and outside of the state of Colorado; identify the relative contributions to atmospheric nitrogen species in RMNP from emission sources along the Colorado Front Range versus other areas within Colorado; and identify the relative contributions to atmospheric nitrogen species from mobile sources, agricultural activities, and large and small point sources within the state of Colorado. Measured ammonia concentrations are combined with modeled releases of conservative tracers from ammonia source regions around the United States to apportion ammonia to its respective sources, using receptor modeling tools.
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Affiliation(s)
- William C Malm
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado 80523-1375, USA.
| | - Bret A Schichtel
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | - Michael G Barna
- National Park Service, Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | - Kristi A Gebhart
- National Park Service, Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | | | - Jeffrey L Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | | | - Katherine B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | - Anthony J Prenni
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1375, USA
| | - Sonia M Kreidenweis
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1375, USA
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Benedict KB, Carrico CM, Kreidenweis SM, Schichtel B, Malm WC, Collett JL. A seasonal nitrogen deposition budget for Rocky Mountain National Park. Ecol Appl 2013; 23:1156-1169. [PMID: 23967583 DOI: 10.1890/12-1624.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Nitrogen deposition is a concern in many protected ecosystems around the world, yet few studies have quantified a complete reactive nitrogen deposition budget including all dry and wet, inorganic and organic compounds. Critical loads that identify the level at which nitrogen deposition negatively affects an ecosystem are often defined using incomplete reactive nitrogen budgets. Frequently only wet deposition of ammonium and nitrate are considered, despite the importance of other nitrogen deposition pathways. Recently, dry deposition pathways including particulate ammonium and nitrate and gas phase nitric acid have been added to nitrogen deposition budgets. However, other nitrogen deposition pathways, including dry deposition of ammonia and wet deposition of organic nitrogen, still are rarely included. In this study, a more complete seasonal nitrogen deposition budget was constructed based on observations during a year-long study period from November 2008 to November 2009 at a location on the east side of Rocky Mountain National Park (RMNP), Colorado, USA. Measurements included wet deposition of ammonium, nitrate, and organic nitrogen, PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 microm, nitrate, and ammonium) concentrations of ammonium, nitrate, and organic nitrogen, and atmospheric gas phase concentrations of ammonia, nitric acid, and NO2. Dry deposition fluxes were determined from measured ambient concentrations and modeled deposition velocities. Total reactive nitrogen deposition by all included pathways was found to be 3.65 kg N x ha(-1) yr(-1). Monthly deposition fluxes ranged from 0.06 to 0.54 kg N x ha(-1)yr(-1), with peak deposition in the month of July and the least deposition in December. Wet deposition of ammonium and nitrate were the two largest deposition pathways, together contributing 1.97 kg N x ha(-1)yr(-1) or 54% of the total nitrogen deposition budget for this region. The next two largest deposition pathways were wet deposition of organic nitrogen and dry deposition of ammonia; combined they contributed 1.37 kg N x ha(-1)yr(-1) or 37% of the total nitrogen deposition budget. To better understand the nitrogen cycle and key interactions between the atmosphere and biosphere we need to include as many sources and types of nitrogen as possible and understand their variability throughout the year. Here we examine the components of the nitrogen deposition budget to better understand the factors that influence the different deposition pathways and their seasonal variations.
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Affiliation(s)
- K B Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523, USA.
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Abstract
In this study, symptom (item) level data were used to perform a psychometric analysis of the DSM-III-R personality disorders (PDs). Determined for each PD criteria set were convergent validity, discriminant validity, and internal consistency. The results indicated that the majority of the PD criteria sets (6 of the 11 ) possessed adequate convergent validity, although discriminant validity was problematic for most of these disorders. Internal consistency was also weak for the PD criteria sets, with only 3 of the 11 exceeding a minimum cutoff score of .70. The present study employed a methodology modeled after the one reported by Morey (1988a), and the results of the two studies were highly similar. Consistent findings across the two data sets can be taken to reflect the actual psychometric properties of the DSM-III-R PDs. The success of our replication demonstrates the potential that large-scale psychometric investigations hold for aiding the development and refinement of the DSM PDs.
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Affiliation(s)
- M A Blais
- Massachusetts General Hospital and Harvard Medical School, Boston 02114, USA
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Abstract
Despite some recent favorable findings, there has not been strong empirical support for the validity of DSM-III-R--and now DSM-IV--personality disorder (PD) clusters. In this study, Axis II symptom ratings on 320 personality disordered patients were used to obtain dimensional scores for the 11 DSM-III-R PDs. The dimensional scores for the DSM PDs were subjected to a principal component analysis with orthoginal rotation. Three factors emerged having eigenvalues > or = than 1. The pattern of factor loadings for the individual PDs were not consistent with the DSM Cluster. Rather, the factor loadings were quite consistent with Millon's theory of personality. These results are discussed in light of the clinical benefits provided by employing empirically determined and theoretically anchored model for organizing the Axis II disorders.
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Affiliation(s)
- M A Blais
- Department of Psychiatry, Massachusetts General Hospital, Boston 02114, USA
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Seidman LJ, Benedict KB, Biederman J, Bernstein JH, Seiverd K, Milberger S, Norman D, Mick E, Faraone SV. Performance of children with ADHD on the Rey-Osterrieth complex figure: a pilot neuropsychological study. J Child Psychol Psychiatry 1995; 36:1459-73. [PMID: 8988278 DOI: 10.1111/j.1469-7610.1995.tb01675.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This study evaluates the performance of boys with Attention Deficit Hyperactivity Disorder (ADHD) on the Rey-Osterrieth Complex Figure (ROCF) taking into consideration familiality and comorbid psychiatric and learning disorders (LD). Sixty-five children with ADHD performed at developmentally lower levels of Copy Organization and Recall Style than did 45 controls. ADHD children with LD scored significantly lower on Copy Organization than did ADHD children without LD, whereas psychiatric comorbidity and familiality had no effect. These results suggest that a developmental analysis of the ROCF identifies organizational difficulties associated with ADHD and that these impairments cannot simply be attributed to comorbidities associated with ADHD.
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Affiliation(s)
- L J Seidman
- Pediatric Psychopharmacology Unit, Massachusetts General Hospital, Boston 02114, USA
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21
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Abstract
The relationships between the three Modifier Indices (Disclosure X, Desirability Y, and Debasement Z) of the Millon Clinical Multiaxial Inventory-II (MCMI-II) and the validity and clinical scales of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) were explored. A sample of 125 psychiatric inpatients was administered both personality measures within 7 days of admission. The pattern of Pearson correlation coefficients and principal component factors was seen as generally supporting the validity of the three MCMI-II Modifier Indices. However, the Disclosure and Debasement Indices were highly intercorrelated and similar in their MMPI-2 associations. The Desirability Index functioned in a more unique manner and demonstrated both convergent and divergent relationships with MMPI-2 Validity and Clinical scales.
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Affiliation(s)
- M A Blais
- Inpatient Psychiatry Service, Massachusetts General Hospital, Boston, 02114, USA
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