40 CFR 63.11428 - Am I subject to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) National Emission Standards for Hazardous Air Pollutants for Wood Preserving Area Sources Applicability and... operate a wood preserving operation that is an area source of hazardous air pollutant (HAP) emissions. (b) The affected source is each new or existing wood preserving operation. (1) An affected source is...

Identifying sources of fugitive emissions in industrial facilities using trajectory statistical methods

NASA Astrophysics Data System (ADS)

Brereton, Carol A.; Johnson, Matthew R.

2012-05-01

Fugitive pollutant sources from the oil and gas industry are typically quite difficult to find within industrial plants and refineries, yet they are a significant contributor of global greenhouse gas emissions. A novel approach for locating fugitive emission sources using computationally efficient trajectory statistical methods (TSM) has been investigated in detailed proof-of-concept simulations. Four TSMs were examined in a variety of source emissions scenarios developed using transient CFD simulations on the simplified geometry of an actual gas plant: potential source contribution function (PSCF), concentration weighted trajectory (CWT), residence time weighted concentration (RTWC), and quantitative transport bias analysis (QTBA). Quantitative comparisons were made using a correlation measure based on search area from the source(s). PSCF, CWT and RTWC could all distinguish areas near major sources from the surroundings. QTBA successfully located sources in only some cases, even when provided with a large data set. RTWC, given sufficient domain trajectory coverage, distinguished source areas best, but otherwise could produce false source predictions. Using RTWC in conjunction with CWT could overcome this issue as well as reduce sensitivity to noise in the data. The results demonstrate that TSMs are a promising approach for identifying fugitive emissions sources within complex facility geometries.

40 CFR 52.2350 - Emission inventories.

Code of Federal Regulations, 2010 CFR

2010-07-01

...). This inventory addresses emissions from point, area, non-road, on-road mobile, and biogenic sources.... The ozone maintenance plan for Salt Lake and Davis Counties that the Governor submitted on February 19... carbon monoxide emissions from stationary point, area, non-road, and on-road mobile sources. (c) On June...

Chemical Preparations Industry: National Emission Standards for Hazardous Air Pollutants for Area Sources

EPA Pesticide Factsheets

National emissions standards for control of hazardous air pollutants (HAP) from the chemical preparations area source category. Includes rule history, Federal Registry citations, implementation information, and additional resources.

Fine particulate matter emissions inventories: comparisons of emissions estimates with observations from recent field programs.

PubMed

Simon, Heather; Allen, David T; Wittig, Ann E

2008-02-01

Emissions inventories of fine particulate matter (PM2.5) were compared with estimates of emissions based on data emerging from U.S. Environment Protection Agency Particulate Matter Supersites and other field programs. Six source categories for PM2.5 emissions were reviewed: on-road mobile sources, nonroad mobile sources, cooking, biomass combustion, fugitive dust, and stationary sources. Ammonia emissions from all of the source categories were also examined. Regional emissions inventories of PM in the exhaust from on-road and nonroad sources were generally consistent with ambient observations, though uncertainties in some emission factors were twice as large as the emission factors. In contrast, emissions inventories of road dust were up to an order of magnitude larger than ambient observations, and estimated brake wear and tire dust emissions were half as large as ambient observations in urban areas. Although comprehensive nationwide emissions inventories of PM2.5 from cooking sources and biomass burning are not yet available, observational data in urban areas suggest that cooking sources account for approximately 5-20% of total primary emissions (excluding dust), and biomass burning sources are highly dependent on region. Finally, relatively few observational data were available to assess the accuracy of emission estimates for stationary sources. Overall, the uncertainties in primary emissions for PM2.s are substantial. Similar uncertainties exist for ammonia emissions. Because of these uncertainties, the design of PM2.5 control strategies should be based on inventories that have been refined by a combination of bottom-up and top-down methods.

Using Eddy Covariance to Quantify Methane Emissions from a Dynamic Heterogeneous Area

EPA Science Inventory

Measuring emissions of CH4, CO2, H2O, and other greenhouse gases from heterogeneous land area sources is challenging. Dynamic changes within the source area as well as changing environmental conditions make individual point measurements less informative than desired, especially w...

Using Eddy Covariance to Quantify Methane Emission from a Dynamic Heterogeneous Area

EPA Science Inventory

Measuring emissions of CH4, CO2, H2O, and other greenhouse gases from heterogeneous land area sources is challenging. Dynamic changes within the source area as well as changing environmental conditions make individual point measurements less informative than desired, especially w...

REVISED EMISSIONS ESTIMATION METHODOLOGIES FOR INDUSTRIAL, RESIDENTIAL, AND ELECTRIC UTILITY STATIONARY COMBUSTION SOURCES

EPA Science Inventory

The report describes the development of improved and streamlined EPA emission estimation methods for stationary combustion area sources by the Joint Emissions Inventory Oversight Group (JEIOG) research program. These sources include categories traditionally labeled "other statio...

Development of Mobile Tracer Correlation Method for Quantification of Emissions from Landfills and Other Large Area Sources

EPA Science Inventory

There is an emerging need to develop cost effective measurement methods for greenhouse gas and air pollutant emissions from large area sources such as landfills, waste water treatment ponds, open area processing units, agricultural operations, CO2 sequestration fields, and site r...

Development of Mobile Tracer Correlation Approach for Quantification of Emissions from Landfills and Other Large Area Sources

EPA Science Inventory

There is a recognized need to develop cost effective measurement methods for greenhouse gas and air pollutant emissions from large area sources such as landfills, waste water treatment ponds, open area processing units, agricultural operations, CO2 sequestration fields, and site ...

Development of a Mobile Tracer Correlation Method for Assessment of Air Emissions from Landfills and Other Area Sources

EPA Science Inventory

Information form the previously approved extended abstract A standardized area source measurement method based on mobile tracer correlation was used for methane emissions assessment in 52 field deployments...

Fact Sheet: Final Rule to Reduce Air Toxics Emissions from Area Source Paints and Allied Products Manufacturing Facilities

EPA Pesticide Factsheets

This page contains a November 2009 fact sheet with information regarding the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Area Sources of Paints and Allied Products Manufacturing.

Flow Charts for Determining Your Requirements: Nine Metal Fabrication and Finishing Source Categories Area Sources National Emission Standards for Hazardous Air Pollutants (NESHAP) Subpart XXXXXX

EPA Pesticide Factsheets

This page contains a July 2008 document that has flow charts to help determine if this National Emission Standards for Hazardous Air Pollutants (NESHAP) rule for Nine metal Fabrication and Finishing Area Source Categories applies to your facility.

Long-term trends in California mobile source emissions and ambient concentrations of black carbon and organic aerosol.

PubMed

McDonald, Brian C; Goldstein, Allen H; Harley, Robert A

2015-04-21

A fuel-based approach is used to assess long-term trends (1970-2010) in mobile source emissions of black carbon (BC) and organic aerosol (OA, including both primary emissions and secondary formation). The main focus of this analysis is the Los Angeles Basin, where a long record of measurements is available to infer trends in ambient concentrations of BC and organic carbon (OC), with OC used here as a proxy for OA. Mobile source emissions and ambient concentrations have decreased similarly, reflecting the importance of on- and off-road engines as sources of BC and OA in urban areas. In 1970, the on-road sector accounted for ∼90% of total mobile source emissions of BC and OA (primary + secondary). Over time, as on-road engine emissions have been controlled, the relative importance of off-road sources has grown. By 2010, off-road engines were estimated to account for 37 ± 20% and 45 ± 16% of total mobile source contributions to BC and OA, respectively, in the Los Angeles area. This study highlights both the success of efforts to control on-road emission sources, and the importance of considering off-road engine and other VOC source contributions when assessing long-term emission and ambient air quality trends.

User's guide for RAM. Volume II. Data preparation and listings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, D.B.; Novak, J.H.

1978-11-01

The information presented in this user's guide is directed to air pollution scientists having an interest in applying air quality simulation models. RAM is a method of estimating short-term dispersion using the Gaussian steady-state model. These algorithms can be used for estimating air quality concentrations of relatively nonreactive pollutants for averaging times from an hour to a day from point and area sources. The algorithms are applicable for locations with level or gently rolling terrain where a single wind vector for each hour is a good approximation to the flow over the source area considered. Calculations are performed for eachmore » hour. Hourly meteorological data required are wind direction, wind speed, temperature, stability class, and mixing height. Emission information required of point sources consists of source coordinates, emission rate, physical height, stack diameter, stack gas exit velocity, and stack gas temperature. Emission information required of area sources consists of southwest corner coordinates, source side length, total area emission rate and effective area source-height. Computation time is kept to a minimum by the manner in which concentrations from area sources are estimated using a narrow plume hypothesis and using the area source squares as given rather than breaking down all sources into an area of uniform elements. Options are available to the user to allow use of three different types of receptor locations: (1) those whose coordinates are input by the user, (2) those whose coordinates are determined by the model and are downwind of significant point and area sources where maxima are likely to occur, and (3) those whose coordinates are determined by the model to give good area coverage of a specific portion of the region. Computation time is also decreased by keeping the number of receptors to a minimum. Volume II presents RAM example outputs, typical run streams, variable glossaries, and Fortran source codes.« less

Process system and method for fabricating submicron field emission cathodes

DOEpatents

Jankowski, A.F.; Hayes, J.P.

1998-05-05

A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape. 3 figs.

Process system and method for fabricating submicron field emission cathodes

DOEpatents

Jankowski, Alan F.; Hayes, Jeffrey P.

1998-01-01

A process method and system for making field emission cathodes exists. The deposition source divergence is controlled to produce field emission cathodes with height-to-base aspect ratios that are uniform over large substrate surface areas while using very short source-to-substrate distances. The rate of hole closure is controlled from the cone source. The substrate surface is coated in well defined increments. The deposition source is apertured to coat pixel areas on the substrate. The entire substrate is coated using a manipulator to incrementally move the whole substrate surface past the deposition source. Either collimated sputtering or evaporative deposition sources can be used. The position of the aperture and its size and shape are used to control the field emission cathode size and shape.

Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

PubMed

Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

2008-06-01

Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

Source Apportionment of VOCs in Edmonton, Alberta

NASA Astrophysics Data System (ADS)

McCarthy, M. C.; Brown, S. G.; Aklilu, Y.; Lyder, D. A.

2012-12-01

Regional emissions at Edmonton, Alberta, are complex, containing emissions from (1) transportation sources, such as cars, trucks, buses, and rail; (2) industrial sources, such as petroleum refining, light manufacturing, and fugitive emissions from holding tanks or petroleum terminals; and (3) miscellaneous sources, such as biogenic emissions and natural gas use and processing. From 2003 to 2009, whole air samples were collected at two sites in Edmonton and analyzed for over 77 volatile organic compounds (VOCs). VOCs were sampled in the downtown area (Central) and the industrial area on the eastern side of the city (East). Concentrations of most VOCs were highest at the East site. The positive matrix factorization (PMF) receptor model was used to apportion ambient concentration measurements of VOCs into eleven factors, which were associated with emissions source categories. Factors of VOCs identified in the final eleven-factor solution include transportation sources (both gasoline and diesel vehicles), industrial sources, a biogenic source, and a natural-gas-related source. Transportation sources accounted for more mass at the Central site than at the East site; this was expected because Central is in a core urban area where transportation emissions are concentrated. Transportation sources accounted for nearly half of the VOC mass at the Central site, but only 6% of the mass at the East site. Encouragingly, mass from transportation sources has declined by about 4% a year in this area; this trend is similar to the decline found throughout the United States, and is likely due to fleet turnover as older, more highly polluting cars are replaced with newer, cleaner cars. In contrast, industrial sources accounted for ten times more VOC mass at the East site than at the Central site and were responsible for most of the total VOC mass observed at the East site. Of the six industrial factors identified at the East site, four were linked to petrochemical industry production and storage. The two largest contributors to VOC mass at the East site were associated with fugitive emissions of volatile species (butanes, pentanes, hexane, and cyclohexane); together, these two factors accounted for more than 50% of the mass at the East site and less than 2% of the mass at the Central site. Natural-gas-related emissions accounted for 10% to 20% of the mass at both sites. Biogenic emissions and VOCs associated with well-mixed global background were less than 10% of the VOC mass at the Central site and less than 3% of the mass at the East site. Controllable emissions sources account for the bulk of the identified VOC mass. Efforts to reduce ozone or particulate matter precursors or exposure to toxic pollutants can now be directed to those sources most important to the Edmonton area.

75 FR 13436 - Approval and Promulgation of State Implementation Plans: Alaska

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-22

... presumptive policies for NO X , ammonia, and VOC for all nonattainment areas. The rule provides a mechanism by... ammonia as a PM 2.5 attainment plan precursor and evaluate sources of ammonia emissions from sources in... specific area showing that ammonia emissions from sources in the State significantly contribute to PM 2.5...

Measuring trace gas emission from multi-distributed sources using vertical radial plume mapping (VRPM) and backward Lagrangian stochastic (bLS) techniques

USDA-ARS?s Scientific Manuscript database

Two micrometeorological techniques for measuring trace gas emission rates from distributed area sources were evaluated using a variety of synthetic area sources. The accuracy of the vertical radial plume mapping (VRPM) and the backward Lagrangian (bLS) techniques with an open-path optical spectrosco...

Development of EPA OTM 10 for Landfill Applications, Interim Report

EPA Science Inventory

Quantification of greenhouse gas emissions from area sources is of increasing importance. Due to the spatial extent and non homogenous nature of many area sources, assessment of fugitive emissions using traditional point sampling techniques can be problematic. To address this, th...

Development and validation of a lead emission inventory for the Greater Cairo area

PubMed Central

Safar, Zeinab; Labib, Mounir W.; Gertler, Alan W.

2013-01-01

Studies that investigate the environmental health risks to Cairo residents invariably conclude that lead is one of the area’s major health hazards. The Cairo Air Improvement Project (CAIP), which was implemented by a team led by Chemonics International, funded by USAID in partnership with the Egyptian Environmental Affairs Agency (EEAA), started developing a lead emission inventory for the greater Cairo (GC) area in 1998. The inventory contains a list by major source of the annual lead emissions in the GC area. Uses of the inventory and associated database include developing effective regulatory and control strategies, assessing emissions trends, and conducting modeling exercises. This paper describes the development of the current lead emissions inventory (1999–2010), along with an approach to develop site specific emission factors and measurements to validate the inventory. This paper discusses the major sources of lead in the GC area, which include lead smelters, Mazout (heavy fuel oil) combustion, lead manufacturing batteries factories, copper foundries, and cement factories. Included will be the trend in the lead emissions inventory with regard to the production capacity of each source category. In addition, the lead ambient measurements from 1999 through 2010 are described and compared with the results of Source Attribution Studies (SAS) conducted in 1999, 2002, and 2010. Due to EEAA/CAIP efforts, a remarkable decrease in more than 90% in lead emissions was attained for 2007. PMID:25685523

A small, lightweight multipollutant sensor system for ground-mobile and aerial emission sampling from open area sources

EPA Science Inventory

Characterizing highly dynamic, transient, and vertically lofted emissions from open area sources poses unique measurement challenges. This study developed and applied a multipollutant sensor and integrated sampler system for use on mobile applications including tethered balloons ...

NATIONAL INVENTORIES FOR AREA SOURCE FUEL COMBUSTION AND GASOLINE MARKETING IN 1999

EPA Science Inventory

The product will be a set of estimates of county-level 1999 emissions of all relevant air pollutants from gasoline marketing and from the combustion of fuel by "area" sources, i.e., those too small be be required to report their emissions individually.

The 1977 emissions inventory for southeastern Virginia. [environment model of air quality based on exhaust emission from urban areas

NASA Technical Reports Server (NTRS)

Brewer, D. A.; Remsberg, E. E.; Woodbury, G. E.; Quinn, L. C.

1979-01-01

Regional tropospheric air pollution modeling and data compilation to simulate the time variation of species concentrations in and around an urban area is discussed. The methods used to compile an emissions inventory are outlined. Emissions factors for vehicular travel in the urban area are presented along with an analysis of the emission gases. Emission sources other than vehicular including industrial wastes, residential solid waste disposal, aircraft emissions, and emissions from the railroads are investigated.

Evaluation of emission control strategies to reduce ozone pollution in the Paso del Norte region using a photochemical air quality modeling system

NASA Astrophysics Data System (ADS)

Valenzuela, Victor Hugo

Air pollution emissions control strategies to reduce ozone precursor pollutants are analyzed by applying a photochemical modeling system. Simulations of air quality conditions during an ozone episode which occurred in June, 2006 are undertaken by increasing or reducing area source emissions in Ciudad Juarez, Chihuahua, Mexico. Two air pollutants are primary drivers in the formation of tropospheric ozone. Oxides of nitrogen (NOx) and volatile organic compounds (VOC) undergo multiple chemical reactions under favorable meteorological conditions to form ozone, which is a secondary pollutant that irritates respiratory systems in sensitive individuals especially the elderly and young children. The U.S. Environmental Protection Agency established National Ambient Air Quality Standards (NAAQS) to limit ambient air pollutants such as ozone by establishing an 8-hour average concentration of 0.075 ppm as the threshold at which a violation of the standard occurs. Ozone forms primarily due reactions in the troposphere of NOx and VOC emissions generated primarily by anthropogenic sources in urban regions. Data from emissions inventories indicate area sources account for ˜15 of NOx and ˜45% of regional VOC emissions. Area sources include gasoline stations, automotive paint bodyshops and nonroad mobile sources. Multiplicity of air pollution emissions sources provides an opportunity to investigate and potentially implement air quality improvement strategies to reduce emissions which contribute to elevated ozone concentrations. A baseline modeling scenario was established using the CAMx photochemical air quality model from which a series of sensitivity analyses for evaluating air quality control strategies were conducted. Modifications to area source emissions were made by varying NOx and / or VOC emissions in the areas of particular interest. Model performance was assessed for each sensitivity analysis. Normalized bias (NB) and normalized error (NE) were used to identify variability of the PREDICTED to OBSERVED ozone concentrations of both BASELINE model and simulations with modified emissions assessed by the sensitivity analysis. All simulations were found to vary within acceptable ranges of these two criteria variables. Simulation results indicate ozone formation in the PdN region is VOC-limited. Under VOC-limited conditions, modifications to NOx emissions do not produce a marked increase or decrease in ozone concentrations. Modifications to VOC emissions generated the highest variability in ozone concentrations. Increasing VOC emissions by 75% produced results which minimized model bias and error when comparing PREDICTED and OBSERVED ozone concentrations. Increasing VOC emissions by 75% either alone or in combination with a 75% increase in NOx emissions generated PREDICTED ozone concentrations very near to OBSERVED ozone. By evaluating the changes in ambient ozone concentrations through photochemical modeling, air quality planners may identify the most efficient or effective VOC emissions control strategies for area sources. Among the strategies to achieve emissions reductions are installation of gasoline vapor recovery systems, replacing high-pressure low-volume surface coating paint spray guns with high-volume low-pressure spray paint guns, requiring emissions control booths for surface coating operations as well as undertaking solvent management practices, requiring the sale of low VOC paint solvents in the surface-coating industry, and requiring low-VOC solvents in the dry cleaning industry. Other strategies to reduce VOC emissions include initiating Eco-Driving strategies to reduce fuel consumption from mobile sources and minimize vehicle idling at the international ports of entry by reducing bridge wait times. This dissertation depicts a tool for evaluating impacts of emissions on regional air quality by addressing the highly unresolved fugitive emissions in the Paso del Norte region. It provides a protocol for decision makers to assess the effects of various emission control strategies in the region. Impacts of specific source categories such as the international ports of entry, gasoline stations, paint body shops, truck stops, and military installations on the regional air quality can be easily and systematically addressed in a timely manner in the future.

Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

PubMed Central

Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

2014-01-01

The upper layer of forest soils (0–20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area. PMID:24599040

Two Model-Based Methods for Policy Analyses of Fine Particulate Matter Control in China: Source Apportionment and Source Sensitivity

NASA Astrophysics Data System (ADS)

Li, X.; Zhang, Y.; Zheng, B.; Zhang, Q.; He, K.

2013-12-01

Anthropogenic emissions have been controlled in recent years in China to mitigate fine particulate matter (PM2.5) pollution. Recent studies show that sulfate dioxide (SO2)-only control cannot reduce total PM2.5 levels efficiently. Other species such as nitrogen oxide, ammonia, black carbon, and organic carbon may be equally important during particular seasons. Furthermore, each species is emitted from several anthropogenic sectors (e.g., industry, power plant, transportation, residential and agriculture). On the other hand, contribution of one emission sector to PM2.5 represents contributions of all species in this sector. In this work, two model-based methods are used to identify the most influential emission sectors and areas to PM2.5. The first method is the source apportionment (SA) based on the Particulate Source Apportionment Technology (PSAT) available in the Comprehensive Air Quality Model with extensions (CAMx) driven by meteorological predictions of the Weather Research and Forecast (WRF) model. The second method is the source sensitivity (SS) based on an adjoint integration technique (AIT) available in the GEOS-Chem model. The SA method attributes simulated PM2.5 concentrations to each emission group, while the SS method calculates their sensitivity to each emission group, accounting for the non-linear relationship between PM2.5 and its precursors. Despite their differences, the complementary nature of the two methods enables a complete analysis of source-receptor relationships to support emission control policies. Our objectives are to quantify the contributions of each emission group/area to PM2.5 in the receptor areas and to intercompare results from the two methods to gain a comprehensive understanding of the role of emission sources in PM2.5 formation. The results will be compared in terms of the magnitudes and rankings of SS or SA of emitted species and emission groups/areas. GEOS-Chem with AIT is applied over East Asia at a horizontal grid resolution of 0.5° (Lat) × 0.67° (Lon). WRF/CAMx with PSAT is applied to nested grids: 36-km × 36-km over China and 12-km × 12-km over northern China. These simulations are performed for 2006 and 2011. Beijing and northern Hebei are selected as representative receptor areas. Simulated surface concentrations by both models are evaluated with available observations in China. Focusing on inorganic aerosols (sulfate, nitrate and ammonium), preliminary SS results from GEOS-Chem/AIT at Beijing identify the top three major emission sectors to be agriculture, residential, and transportation in winter and agriculture, industry and power plant in summer. The top four source areas are northern Hebei, local, Neimenggu, and Liaoning in winter and northern Hebei, local, Shandong, and southern Hebei in summer. The synthesis of SS and SA for influential emission groups or areas from this work will provide a quantitative basis for emission control strategy development and policy making for PM2.5 control in China.

Development of unauthorized airborne emission source identification procedure

NASA Astrophysics Data System (ADS)

Shtripling, L. O.; Bazhenov, V. V.; Varakina, N. S.; Kupriyanova, N. P.

2018-01-01

The paper presents the procedure for searching sources of unauthorized airborne emissions. To make reasonable regulation decisions on airborne pollutant emissions and to ensure the environmental safety of population, the procedure provides for the determination of a pollutant mass emission value from the source being the cause of high pollution level and the search of a previously unrecognized contamination source in a specified area. To determine the true value of mass emission from the source, the minimum of the mean-root-square mismatch criterion between the computed and measured pollutant concentration in the given location is used.

Aerostat-lofted instrument and sampling method for determination of emissions from open area sources

EPA Science Inventory

An aerostat-borne instrument and sampling method was developed to characterize air samples from area sources, such as emissions from open burning. The 10 kg battery-powered instrument system, termed "the Flyer," is lofted with a helium-filled aerostat of 4 m nominal diameter and ...

Development of Mobile Tracer Correlation Method for Assessment of Air Emissions from Landfills and Other Area Sources

EPA Science Inventory

Abstract - A standardized version of a mobile tracer correlation measurement method was developed and used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. This general area source measurement method uses advances in instrumentation...

Characteristics of organic matter in PM2.5 from an e-waste dismantling area in Taizhou, China.

PubMed

Gu, Zeping; Feng, Jialiang; Han, Wenliang; Wu, Minghong; Fu, Jiamo; Sheng, Guoying

2010-08-01

Solvent extractable organic compounds in PM(2.5) samples collected in Taizhou, a city famous for its electrical and electronic waste (e-waste) recycling industry in Zhejiang province of China, were analyzed to identify the main emission sources based on molecular markers. Two types of plastics which were most frequently contained in the e-wastes, wires/cables and plastic blocks, were burned in the lab and the particles emitted analyzed. The concentrations of PAHs and phthalate esters at the e-waste dismantling area during our sampling periods were about two times of that at the reference urban site, indicating the high pollution level there. The high concentrations of quaterphenyl found at the dismantling area indicated that burning of plastics or polymers was an important emission source of the PAHs in the fine particles. The diagnostic analysis based on the compositions of alkanes, hopanes and other molecular markers showed that engine exhaust, biomass burning and kitchen emissions were also important emission sources at the e-waste dismantling area. Our results suggested that more effort should be paid to control the correlative emission sources such as transportation and kitchen to achieve better air quality at the e-waste dismantling area besides regulating the recycling activities. Copyright 2010 Elsevier Ltd. All rights reserved.

EPA's mobile monitoring of source emissions and near-source impact

EPA Science Inventory

Real-time ambient monitoring onboard a moving vehicle is a unique data collection approach applied to characterize large-area sources, such as major roadways, and detect fugitive emissions from distributed sources, such as leaking oil wells. EPA's Office of Research and Developme...

Water Pollution Prediction in the Three Gorges Reservoir Area and Countermeasures for Sustainable Development of the Water Environment.

PubMed

Li, Yinghui; Huang, Shuaijin; Qu, Xuexin

2017-10-27

The Three Gorges Project was implemented in 1994 to promote sustainable water resource use and development of the water environment in the Three Gorges Reservoir Area (hereafter "Reservoir Area"). However, massive discharge of wastewater along the river threatens these goals; therefore, this study employs a grey prediction model (GM) to predict the annual emissions of primary pollution sources, including industrial wastewater, domestic wastewater, and oily and domestic wastewater from ships, that influence the Three Gorges Reservoir Area water environment. First, we optimize the initial values of a traditional GM (1,1) model, and build a new GM (1,1) model that minimizes the sum of squares of the relative simulation errors. Second, we use the new GM (1,1) model to simulate historical annual emissions data for the four pollution sources and thereby test the effectiveness of the model. Third, we predict the annual emissions of the four pollution sources in the Three Gorges Reservoir Area for a future period. The prediction results reveal the annual emission trends for the major wastewater types, and indicate the primary sources of water pollution in the Three Gorges Reservoir Area. Based on our predictions, we suggest several countermeasures against water pollution and towards the sustainable development of the water environment in the Three Gorges Reservoir Area.

Estimation of the local and long-range contributions to particulate matter levels using continuous measurements in a single urban background site

NASA Astrophysics Data System (ADS)

Diamantopoulou, Marianna; Skyllakou, Ksakousti; Pandis, Spyros N.

2016-06-01

The Particulate Matter Source Apportionment Technology (PSAT) algorithm is used together with PMCAMx, a regional chemical transport model, to develop a simple observation-based method (OBM) for the estimation of local and regional contributions of sources of primary and secondary pollutants in urban areas. We test the hypothesis that the minimum of the diurnal average concentration profile of the pollutant is a good estimate of the average contribution of long range transport levels. We use PMCAMx to generate "pseudo-observations" for four different European cities (Paris, London, Milan, and Dusseldorf) and PSAT to estimate the corresponding "true" local and regional contributions. The predictions of the proposed OBM are compared to the "true" values for different definitions of the source area. During winter, the estimates by the OBM for the local contributions to the concentrations of total PM2.5, primary pollutants, and sulfate are within 25% of the "true" contributions of the urban area sources. For secondary organic aerosol the OBM overestimates the importance of the local sources and it actually estimates the contributions of sources within 200 km from the receptor. During summer for primary pollutants and cities with low nearby emissions (ratio of emissions in an area extending 100 km from the city over local emissions lower than 10) the OBM estimates correspond to the city emissions within 25% or so. For cities with relatively high nearby emissions the OBM estimates correspond to emissions within 100 km from the receptor. For secondary PM2.5 components like sulfate and secondary organic aerosol the OBM's estimates correspond to sources within 200 km from the receptor. Finally, for total PM2.5 the OBM provides approximately the contribution of city emissions during the winter and the contribution of sources within 100 km from the receptor during the summer.

Characterizing sources of emissions from wildland fires

Treesearch

Roger D. Ottmar; Ana Isabel Miranda; David V. Sandberg

2009-01-01

Smoke emissions from wildland fire can be harmful to human health and welfare, impair visibility, and contribute to greenhouse gas emissions. The generation of emissions and heat release need to be characterized to estimate the potential impacts of wildland fire smoke. This requires explicit knowledge of the source, including size of the area burned, burn period,...

75 FR 12988 - National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

... roofing manufacturing area source category (74 FR 63236). Following signature of this final rule, EPA...). Following signature of the final asphalt processing and asphalt roofing manufacturing area source standards...

Emissions from Combustion of Open Area Sources: Prescribed Forest and Agricultural Burns

EPA Science Inventory

Emissions from wildfires and prescribed forest and agricultural burns generate a variety of emissions that can cause adverse health effects for humans, contribute to climate change, and decrease visibility. Only limited pollutant data are available for these sources, particularly...

Next Generation Emission Measurements for Fugitive, Area Source, and Fence Line Applications?

EPA Science Inventory

Next generation emissions measurements (NGEM) is an EPA term for the rapidly advancing field of air pollutant sensor technologies, data integration concepts, and associated geospatial modeling strategies for source emissions measurements. Ranging from low coat sensors to satelli...

Development and evaluation of a lightweight sensor system for aerial emission sampling from open area sources

EPA Science Inventory

A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

Development and evaluation of a lightweight sensor system for aerial emission sampling from open area sources (Abstract)

EPA Science Inventory

A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

Development and evaluation of a lightweight sensor system for emission sampling from open area sources

EPA Science Inventory

A new sensor system for mobile and aerial emission sampling was developed for open area sources, such as open burning. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, and black carbon, samplers for particulate matter with ...

Development of a Mobile Tracer Correlation Method for Assessment of Air Emissions from Landfills and Other Area Sources (Abstract)

EPA Science Inventory

Work toward a standardized version of a mobile tracer correlation measurement method is discussed. The method used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. This general area source measurement method uses advances in instrum...

VALIDATION OF A METHOD FOR ESTIMATING POLLUTION EMISSION RATES FROM AREA SOURCES USING OPEN-PATH FTIR SEPCTROSCOPY AND DISPERSION MODELING TECHNIQUES

EPA Science Inventory

The paper describes a methodology developed to estimate emissions factors for a variety of different area sources in a rapid, accurate, and cost effective manner. he methodology involves using an open-path Fourier transform infrared (FTIR) spectrometer to measure concentrations o...

Summary of 2012 Reconsideration Public Comments and Responses for Industrial, Commercial, and Institutional Boilers at Area Sources: National Emission Standards for Hazardous Air Pollutants (NESHAP)

EPA Pesticide Factsheets

This page has a 12/2012 document that provides EPA’s responses to public comments on EPA’s Proposed National Emission Standards for Hazardous Air Pollutants for Area Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters

NO2 and SO2 dispersion modeling and relative roles of emission sources over Map Ta Phut industrial area, Thailand.

PubMed

Chusai, Chatinai; Manomaiphiboon, Kasemsan; Saiyasitpanich, Phirun; Thepanondh, Sarawut

2012-08-01

Map Ta Phut industrial area (MA) is the largest industrial complex in Thailand. There has been concern about many air pollutants over this area. Air quality management for the area is known to be difficult, due to lack of understanding of how emissions from different sources or sectors (e.g., industrial, power plant, transportation, and residential) contribute to air quality degradation in the area. In this study, a dispersion study of NO2 and SO2 was conducted using the AERMOD model. The area-specific emission inventories of NOx and SO2 were prepared, including both stack and nonstack sources, and divided into 11 emission groups. Annual simulations were performed for the year 2006. Modeled concentrations were evaluated with observations. Underestimation of both pollutants was Jbund, and stack emission estimates were scaled to improve the modeled results before quantifying relative roles of individual emission groups to ambient concentration overfour selected impacted areas (two are residential and the others are highly industrialized). Two concentration measures (i.e., annual average area-wide concentration or AC, and area-wide robust highest concentration or AR) were used to aggregately represent mean and high-end concentrations Jbfor each individual area, respectively. For AC-NO2, on-road mobile emissions were found to be the largest contributor in the two residential areas (36-38% of total AC-NO2), while petrochemical-industry emissions play the most important role in the two industrialized areas (34-51%). For AR-NO2, biomass burning has the most influence in all impacted areas (>90%) exceptJor one residential area where on-road mobile is the largest (75%). For AC-SO2, the petrochemical industry contributes most in all impacted areas (38-56%). For AR-SO2, the results vary. Since the petrochemical industry was often identified as the major contributor despite not being the largest emitter, air quality workers should pay special attention to this emission group when managing air quality for the MA.

NO2 and SO2dispersion modeling and relative roles of emission sources over Map Ta Phut industrial area, Thailand.

PubMed

Chusai, Chatinai; Manomaiphiboon, Kasemsan; Saiyasitpanich, Phirun; Thepanondh, Sarawut

2012-08-01

Map Ta Phut industrial area (MA) is the largest industrial complex in Thailand. There has been concern about many air pollutants over this area. Air quality management for the area is known to be difficult, due to lack of understanding of how emissions from different sources or sectors (e.g., industrial, power plant, transportation, and residential) contribute to air quality degradation in the area. In this study, a dispersion study of NO 2 and SO 2 was conducted using the AERMOD model. The area-specific emission inventories of NO x and SO 2 were prepared, including both stack and nonstack sources, and divided into 11 emission groups. Annual simulations were performed for the year 2006. Modeled concentrations were evaluated with observations. Underestimation of both pollutants was found, and stack emission estimates were scaled to improve the modeled results before quantifying relative roles of individual emission groups to ambient concentration over four selected impacted areas (two are residential and the others are highly industrialized). Two concentration measures (i.e., annual average area-wide concentration or AC, and area-wide robust highest concentration or AR) were used to aggregately represent mean and high-end concentrations for each individual area, respectively. For AC-NO 2 , on-road mobile emissions were found to be the largest contributor in the two residential areas (36-38% of total AC-NO 2 ), while petrochemical-industry emissions play the most important role in the two industrialized areas (34-51%). For AR-NO 2 , biomass burning has the most influence in all impacted areas (>90%) except for one residential area where on-road mobile is the largest (75%). For AC-SO 2 , the petrochemical industry contributes most in all impacted areas (38-56%). For AR-SO 2 , the results vary. Since the petrochemical industry was often identified as the major contributor despite not being the largest emitter, air quality workers should pay special attention to this emission group when managing air quality for the MA. [Box: see text] [Box: see text].

[Spatial heterogeneity and classified control of agricultural non-point source pollution in Huaihe River Basin].

PubMed

Zhou, Liang; Xu, Jian-Gang; Sun, Dong-Qi; Ni, Tian-Hua

2013-02-01

Agricultural non-point source pollution is of importance in river deterioration. Thus identifying and concentrated controlling the key source-areas are the most effective approaches for non-point source pollution control. This study adopts inventory method to analysis four kinds of pollution sources and their emissions intensity of the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in 173 counties (cities, districts) in Huaihe River Basin. The four pollution sources include livestock breeding, rural life, farmland cultivation, aquacultures. The paper mainly addresses identification of non-point polluted sensitivity areas, key pollution sources and its spatial distribution characteristics through cluster, sensitivity evaluation and spatial analysis. A geographic information system (GIS) and SPSS were used to carry out this study. The results show that: the COD, TN and TP emissions of agricultural non-point sources were 206.74 x 10(4) t, 66.49 x 10(4) t, 8.74 x 10(4) t separately in Huaihe River Basin in 2009; the emission intensity were 7.69, 2.47, 0.32 t.hm-2; the proportions of COD, TN, TP emissions were 73%, 24%, 3%. The paper achieves that: the major pollution source of COD, TN and TP was livestock breeding and rural life; the sensitivity areas and priority pollution control areas among the river basin of non-point source pollution are some sub-basins of the upper branches in Huaihe River, such as Shahe River, Yinghe River, Beiru River, Jialu River and Qingyi River; livestock breeding is the key pollution source in the priority pollution control areas. Finally, the paper concludes that pollution type of rural life has the highest pollution contribution rate, while comprehensive pollution is one type which is hard to control.

Spatial and temporal variation of historical anthropogenic NMVOCs emission inventories in China

NASA Astrophysics Data System (ADS)

Bo, Y.; Cai, H.; Xie, S. D.

2008-12-01

Multiyear emission inventories of anthropogenic NMVOCs in China for 1980-2005 were established based on time-varying statistical data, literature surveyed and model calculated emission factors, which were further gridded at a high spatial resolution of 40 km×40 km using the GIS methodology. Results show a continuous growth trend of China's historical NMVOCs emissions during the period of 1980-2005, with the emission increasing by 4.2 times at an annual average rate of 10.6% from 3.91 Tg in 1980 to 16.49 Tg in 2005. Vehicles, biomass burning, industrial processes, fossil fuel combustion, solvent utilization, and storage and transport generated 5.50 Tg, 3.84 Tg, 2.76 Tg, 1.98 Tg, 1.87 Tg, and 0.55 Tg of NMVOCs, respectively, in 2005. Motorcycles, biofuel burning, heavy duty vans, synthetic fibre production, biomass open burning, and industrial and commercial consumption were primary emission sources. Besides, source contributions of NMVOCs emissions showed remarkable annual variation. However, emissions of these sources had been continuously increasing, which coincided well with China's economic growth. Spatial distribution of NMVOCs emissions illustrates that high emissions mainly concentrates in developed regions of northern, eastern and southern coastal areas, which produced more emissions than the relatively underdeveloped western and inland regions. Particularly, southeastern, northern, and central China covering 35.2% of China's territory, generated 59.4% of the total emissions, while the populous capital cities covering merely 4.5% of China's territory, accounted for 24.9% of the national emissions. Annual variation of regional emission intensity shows that emissions concentrating in urban areas tended to transfer to rural areas year by year. Moreover, eastern, southern, central, and northeastern China were typical areas of high emission intensity and had a tendency of expanding to the northwestern China, which revealed the transfer of emission-intensive plants to these areas, together with the increase of biomass open burning.

Evaluating Bay Area Methane Emission Inventory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Marc; Jeong, Seongeun

As a regulatory agency, evaluating and improving estimates of methane (CH4) emissions from the San Francisco Bay Area is an area of interest to the Bay Area Air Quality Management District (BAAQMD). Currently, regional, state, and federal agencies generally estimate methane emissions using bottom-up inventory methods that rely on a combination of activity data, emission factors, biogeochemical models and other information. Recent atmospheric top-down measurement estimates of methane emissions for the US as a whole (e.g., Miller et al., 2013) and in California (e.g., Jeong et al., 2013; Peischl et al., 2013) have shown inventories underestimate total methane emissions bymore » ~ 50% in many areas of California, including the SF Bay Area (Fairley and Fischer, 2015). The goal of this research is to provide information to help improve methane emission estimates for the San Francisco Bay Area. The research effort builds upon our previous work that produced methane emission maps for each of the major source sectors as part of the California Greenhouse Gas Emissions Measurement (CALGEM) project (http://calgem.lbl.gov/prior_emission.html; Jeong et al., 2012; Jeong et al., 2013; Jeong et al., 2014). Working with BAAQMD, we evaluate the existing inventory in light of recently published literature and revise the CALGEM CH4 emission maps to provide better specificity for BAAQMD. We also suggest further research that will improve emission estimates. To accomplish the goals, we reviewed the current BAAQMD inventory, and compared its method with those from the state inventory from the California Air Resources Board (CARB), the CALGEM inventory, and recent published literature. We also updated activity data (e.g., livestock statistics) to reflect recent changes and to better represent spatial information. Then, we produced spatially explicit CH4 emission estimates on the 1-km modeling grid used by BAAQMD. We present the detailed activity data, methods and derived emission maps by sector. In total, we estimate the anthropogenic emissions for BAAQMD to be 116.4 Gg (1 Gg = 109 g) CH4/yr, with a likely uncertainty of ~ 50% or more (e.g., NRC, 2010; US-EPA, 2015). Including the emissions from wetland (Jeong et al., 2013), the total CH4 emission estimate for BAAQMD is 120.1 Gg CH4/yr. Table 1 summarizes the estimated CH4 emissions for 2011 by sector. The sectors were categorized following those that are used in recent regional emission quantification studies (e.g., Jeong et al., 2013; Peischl et al., 2013; Wecht et al., 2014). However, we note that this result is marginally lower than the top-down estimate of 240 ± 60 Gg CH4/yr (at 95% confidence) reported by Fairley and Fischer (2015), suggesting some combination of systematic error in the top-down estimate, underestimation of emissions from known sources, or as yet unidentified sources may be present. With respect to the relative contributions from different source sectors, the CH4 emissions from the region are dominated by urban activities. Landfill emissions represent 53% of the District’s total emission followed by livestock (16%) and natural gas (15%). These three dominant sectors account for 84% of the total anthropogenic emission in BAAQMD. This suggests that mitigation efforts need to focus on these three sources. Figure 1 shows the gridded anthropogenic CH4 emissions on the BAAQMD’s 1-km grid. In general, the spatial pattern of emissions follows the density of population while strong point sources are also distributed in the rural areas of the District. Detailed methods and emissions for each sector and county are described in the following sections.« less

40 CFR 63.11409 - What are the standards?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... capture system that collects the gases and fumes released during the operation of each emissions source...

40 CFR 63.11409 - What are the standards?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... capture system that collects the gases and fumes released during the operation of each emissions source...

40 CFR 63.11409 - What are the standards?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... capture system that collects the gases and fumes released during the operation of each emissions source...

40 CFR 63.11409 - What are the standards?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... capture system that collects the gases and fumes released during the operation of each emissions source...

40 CFR 63.11409 - What are the standards?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... capture system that collects the gases and fumes released during the operation of each emissions source...

Annual emissions of mercury to the atmosphere from natural sources in Nevada and California

USGS Publications Warehouse

Coolbaugh, M.F.; Gustin, M.S.; Rytuba, J.J.

2002-01-01

The impact of natural source emissions on atmospheric mercury concentrations and the biogeochemical cycle of mercury is not known. To begin to assess this impact, mercury emissions to the atmosphere were scaled up for three areas naturally enriched in mercury: the Steamboat Springs geothermal area, Nevada, the New Idria mercury mining district, California, and the Medicine Lake volcano, California. Data used to scale up area emissions included mercury fluxes, measured in-situ using field flux chambers, from undisturbed and disturbed geologic substrates, and relationships between mercury emissions and geologic rock types, soil mercury concentrations, and surface heat flux. At select locations mercury fluxes were measured for 24 h and the data were used to adjust fluxes measured at different times of the day to give an average daily flux. This adjustment minimized daily temporal variability, which is observed for mercury flux because of light and temperature effects. Area emissions were scaled spatially and temporally with GIS software. Measured fluxes ranged from 0.3 to approximately 50 ng m-2 h-1 at undisturbed sites devoid of mercury mineralization, and to greater than 10,000 ng m-2 h-1 from substrates that were in areas of mercury mining. Area-averaged fluxes calculated for bare soil at Steamboat Springs, New Idria, and Medicine Lake of 181, 9.2, and 2 ng m-2 h-1, respectively, are greater than fluxes previously ascribed to natural non-point sources, indicating that these sources may be more significant contributors of mercury to the atmosphere than previously realized.

Identification of specific sources of airborne particles emitted from within a complex industrial (steelworks) site

NASA Astrophysics Data System (ADS)

Beddows, D. C. S.; Harrison, Roy M.

2018-06-01

A case study is provided of the development and application of methods to identify and quantify specific sources of emissions from within a large complex industrial site. Methods include directional analysis of concentrations, chemical source tracers and correlations with gaseous emissions. Extensive measurements of PM10, PM2.5, trace gases, particulate elements and single particle mass spectra were made at sites around the Port Talbot steelworks in 2012. By using wind direction data in conjunction with real-time or hourly-average pollutant concentration measurements, it has been possible to locate areas within the steelworks associated with enhanced pollutant emissions. Directional analysis highlights the Slag Handling area of the works as the most substantial source of elevated PM10 concentrations during the measurement period. Chemical analyses of air sampled from relevant wind directions is consistent with the anticipated composition of slags, as are single particle mass spectra. Elevated concentrations of PM10 are related to inverse distance from the Slag Handling area, and concentrations increase with increased wind speed, consistent with a wind-driven resuspension source. There also appears to be a lesser source associated with Sinter Plant emissions affecting PM10 concentrations at the Fire Station monitoring site. The results are compared with a ME2 study using some of the same data, and shown to give a clearer view of the location and characteristics of emission sources, including fugitive dusts.

75 FR 10420 - Approval and Promulgation of Implementation Plans: 1-Hour Ozone Extreme Area Plan for San Joaquin...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-08

... rulemaking. A. Emissions Inventory Comment: Earthjustice comments on the importance of emission inventories..., accurate, current inventory of actual emissions from all sources of the relevant pollutant or pollutants in such area.'' It also comments that ARB submitted to EPA new emissions inventories for ozone precursors...

Estimation of River Towboat Air Pollution in Saint Louis, Missouri

DOT National Transportation Integrated Search

1976-02-01

The study gives an estimate of river towboat air pollution emissions for the St. Louis Air Pollution Study area. No emissions from secondary sources or from recreational boating on the river of other areas are considered. The emission estimate is bas...

OPEN PATH TUNABLE DIODE LASER ABSORPTION SPECTROSCOPY FOR ACQUISITION OF FUGITIVE EMISSION FLUX DATA

EPA Science Inventory

Air pollutant emission from unconfined sources is an increasingly important environmental issue. The U.S. EPA has developed a gorund-based optical remote sensing method that enables direct measurement of fugitive emission flux from large area sources. Open-path Fourier transfor...

Composition and source apportionment of PM1 at urban site Kanpur in India using PMF coupled with CBPF

NASA Astrophysics Data System (ADS)

Rai, Pragati; Chakraborty, Abhishek; Mandariya, Anil Kumar; Gupta, Tarun

2016-09-01

This study addresses the three major questions: (1) what are the emission sources of PM1 which are affecting the study area; (2) where do these emission sources come from; and (3) is there any temporal variation in the emission sources. To address these issues, two advanced statistical methods are described in this paper. Identification of emission sources was performed by EPA PMF (v 5.0) and to understand the temporal variability, sampling was done for three winter seasons 2008-09, 2009-10 and 2011-12 within Kanpur city. To identify the possible source directions, Conditional Bivariate Probability function (CBPF) was used. The average PM1 concentration was higher in 2008-09 followed by 2011-12 and 2009-10 winter seasons. 2008-09 winter showed sources such as secondary sources mixed with power plant emission (42.8%), industrial emission (32.3%), coal combustion, brick kilns and vehicular emission (13.2%) and residual oil combustion and road dust (11.7%). The major contributors during winter season 2009-10 were secondary sources (33.1%), biomass burning (23.3%), heavy oil combustion (13%), vehicular emission mixed with crustal dust (11.3%), leather tanning industries (10.3%), industrial emission (4%), coal combustion and brick kilns (3.4%) and solid waste burning and incineration (1.5%) compared to secondary sources mixed with biomass burning (42.3%), industrial emission and crustal dust (35.1%) and vehicular emission and brick kilns (22.6%) during 2011-12 winter season. PMF model revealed that secondary sources were the main contributors for all the three winter seasons followed by biomass burning and power plant emission. The results of CBPF analysis agreed well with the locations of known local point sources., e.g. in the case of industrial emissions, the maximum probability was in the direction between NES direction where almost all the major industries are located in and around Kanpur while in the opposite direction the probability of biomass burning was high due to a rural area in NWS direction.

CH4 emission estimates from an active landfill site inferred from a combined approach of CFD modelling and in situ FTIR measurements

NASA Astrophysics Data System (ADS)

Sonderfeld, Hannah; Boesch, Hartmut; Jeanjean, Antoine P. R.; Riddick, Stuart N.; Allen, Grant; Ars, Sebastien; Davies, Stewart; Harris, Neil; Humpage, Neil; Leigh, Roland; Pitt, Joseph

2017-04-01

Globally, the waste sector contributes to nearly a fifth of anthropogenic methane (CH4) emitted to the atmosphere and is the second largest source of methane in the UK. In recent years great improvements to reduce those emissions have been achieved by installation of methane recovery systems at landfill sites and subsequently methane emissions reported in national emission inventories have been reduced. Nevertheless, methane emissions of landfills remain uncertain and quantification of emission fluxes is essential to verify reported emission inventories and to monitor changes in emissions. We are presenting data from the deployment of an in situ FTIR (Fourier Transform Infrared Spectrometer, Ecotech) for continuous and simultaneous sampling of CO2, CH4, N2O and CO with high time resolution of the order of minutes. During a two week field campaign at an operational landfill site in Eastern England in August 2014, measurements were taken within a radius of 320 m of the uncovered and active area of the landfill, which was still filled with new incoming waste. We have applied a computation fluid dynamics (CFD) model, constrained with local wind measurements and a detailed topographic map of the landfill site, to the in situ concentration data to calculate CH4 fluxes of the active site. A mean daytime flux of 0.83 mg m-2 s-1 (53.26 kg h-1) was calculated for the area of the active site. An additional source area was identified and incorporated into the CFD model, which resulted in higher total methane emissions of 75.97 kg h-1 for the combined emission areas. Our method of combining a CFD model to in situ data, in medium proximity of the source area, allows to distinguish between different emission areas and thereby provide more detailed information compared to bulk emission approaches.

BTEX exposures in an area impacted by industrial and mobile sources: Source attribution and impact of averaging time.

PubMed

Presto, Albert A; Dallmann, Timothy R; Gu, Peishi; Rao, Unnati

2016-04-01

The impacts of emissions plumes from major industrial sources on black carbon (BC) and BTEX (benzene, toluene, ethyl benzene, xylene isomers) exposures in communities located >10 km from the industrial source areas were identified with a combination of stationary measurements, source identification using positive matrix factorization (PMF), and dispersion modeling. The industrial emissions create multihour plume events of BC and BTEX at the measurement sites. PMF source apportionment, along with wind patterns, indicates that the observed pollutant plumes are the result of transport of industrial emissions under conditions of low boundary layer height. PMF indicates that industrial emissions contribute >50% of outdoor exposures of BC and BTEX species at the receptor sites. Dispersion modeling of BTEX emissions from known industrial sources predicts numerous overnight plumes and overall qualitative agreement with PMF analysis, but predicts industrial impacts at the measurement sites a factor of 10 lower than PMF. Nonetheless, exposures associated with pollutant plumes occur mostly at night, when residents are expected to be home but are perhaps unaware of the elevated exposure. Averaging data samples over long times typical of public health interventions (e.g., weekly or biweekly passive sampling) misapportions the exposure, reducing the impact of industrial plumes at the expense of traffic emissions, because the longer samples cannot resolve subdaily plumes. Suggestions are made for ways for future distributed pollutant mapping or intervention studies to incorporate high time resolution tools to better understand the potential impacts of industrial plumes. Emissions from industrial or other stationary sources can dominate air toxics exposures in communities both near the source and in downwind areas in the form of multihour plume events. Common measurement strategies that use highly aggregated samples, such as weekly or biweekly averages, are insensitive to such plume events and can lead to significant under apportionment of exposures from these sources.

Nitrogen saturation in the Rocky Mountains: Linking emissions, deposition, and ecosystem effects using stable isotopes of nitrogen compounds

USGS Publications Warehouse

Campbell, D.H.; Nanus, L.; Böhlke, J.K.; Harlin, K.; Collett, J.

2007-01-01

Elevated levels of atmospheric N deposition are affecting terrestrial and aquatic ecosystems at high elevations in Rocky Mountain National Park and adjacent areas of the Front Range of Colorado. Federal and state agencies are now working together to develop cost-effective means for reducing atmospheric N deposition. A discussion on N saturation covers the need for better understanding of N emission source areas and source types that contribute to N deposition in the Rocky Mountains Front Range of Colorado; reductions in NO emissions that resulted from Clean Air Act Amendments, which caused NO3 deposition to decrease between 1984 and 2003; factors contributing to N deposition, e.g., rapid population growth and energy development; origins of NO3, e.g., as NO emissions from fossil fuel combustion, including stationary sources (e.g. emission from coal combustion in electric generating units), and mobile sources (vehicle emissions); disperse stationary sources from energy resource development, e.g., natural gas production; and the importance of incorporating local source characterization and finer spatial and temporal sampling into future studies, which could provide additional insight into N deposition source attribution. This is an abstract of a paper presented at the 100th Annual Conference and Exhibition of the Air and Waste Management Association (Pittsburgh, PA 6/26-29/2007).

Identification of phosphorus emission hotspots in agricultural catchments

PubMed Central

Kovacs, Adam; Honti, Mark; Zessner, Matthias; Eder, Alexander; Clement, Adrienne; Blöschl, Günter

2012-01-01

An enhanced transport-based management approach is presented, which is able to support cost-effective water quality management with respect to diffuse phosphorus pollution. Suspended solids and particulate phosphorus emissions and their transport were modeled in two hilly agricultural watersheds (Wulka River in Austria and Zala River in Hungary) with an improved version of the catchment-scale PhosFate model. Source and transmission areas were ranked by an optimization method in order to provide a priority list of the areas of economically efficient (optimal) management alternatives. The model was calibrated and validated at different gauges and for various years. The spatial distribution of the emissions shows that approximately one third of the catchment area is responsible for the majority of the emissions. However, only a few percent of the source areas can transport fluxes to the catchment outlet. These effective source areas, together with the main transmission areas are potential candidates for improved management practices. In accordance with the critical area concept, it was shown that intervention with better management practices on a properly selected small proportion of the total area (1–3%) is sufficient to reach a remarkable improvement in water quality. If soil nutrient management is also considered in addition to water quality, intervention on 4–12% of the catchment areas can fulfill both aspects. PMID:22771465

IDENTIFICATION AND CHARACTERIZATION OF MISSING AND UNACCOUNTED FOR AREA SOURCE CATEGORIES

EPA Science Inventory

The report identifies and characterizes missing or unaccounted for area source categories. Area source emissions of particulate matter (TSP), sulfur dioxide (SO2), oxides of nitrogen (NOx), reactive volatile organic compounds (VOCs), and carbon monoxide (CO) are estimated annuall...

Atmospheric polycyclic aromatic hydrocarbons in the urban environment: Occurrence, toxicity and source apportionment.

PubMed

Mishra, Nitika; Ayoko, Godwin A; Morawska, Lidia

2016-01-01

Polycyclic Aromatic Hydrocarbons (PAHs) represent a major class of toxic pollutants because of their carcinogenic and mutagenic characteristics. People living in urban areas are regularly exposed to PAHs because of abundance of their emission sources. Within this context, this study aimed to: (i) identify and quantify the levels of ambient PAHs in an urban environment; (ii) evaluate their toxicity; and (iii) identify their sources as well as the contribution of specific sources to measured concentrations. Sixteen PAHs were identified and quantified in air samples collected from Brisbane. Principal Component Analysis - Absolute Principal Component Scores (PCA-APCS) was used in order to conduct source apportionment of the measured PAHs. Vehicular emissions, natural gas combustion, petrol emissions and evaporative/unburned fuel were the sources identified; contributing 56%, 21%, 15% and 8% of the total PAHs emissions, respectively, all of which need to be considered for any pollution control measures implemented in urban areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sources of nitrous oxide and other climate relevant gases on surface area in a dairy free stall barn with solid floor and outside slurry storage

NASA Astrophysics Data System (ADS)

Schmithausen, Alexander J.; Trimborn, Manfred; Büscher, Wolfgang

2018-04-01

Livestock production systems in agriculture are one of the major emitters of greenhouse gases. So far, the focus of research in the dairy farm sector was primarily on ruminal methane (CH4) emissions. Emissions of nitrous oxide (N2O) usually arise from solid manure or in deep litter free stall barns. Release of N2O occurs as a result of interactions between organic material, nitrogen and moisture. Data of N2O emissions from modern dairy barns and liquid manure management systems are rare. Thus, the goal of this research was to determine the main sources of trace gas emissions at the dairy farm level, including N2O. Areas such as the scraped surface area where dry and wet conditions alternate are interesting. Possible sources of trace gases within and outside the barn were localised by measuring trace gas concentration rates from different dairy farm areas (e.g., areas covered with urine and excrement or slurry storage system) via the closed chamber technique. The results indicate typical emission ratios of carbon dioxide (CO2), CH4 and N2O in the various areas to generate comparable equivalent values. Calculated on the basis of nitrogen excretion from dairy cows, total emissions of N2O were much lower from barns than typically measured in fields. However, there were also areas within the barn with individual events and unexpected release factors of N2O concentrations such as urine patches, polluted areas and cubicles. Emission factors of N2O ranged from 1.1 to 5.0 mg m-2 d-1, respectively, for cleaned areas and urine patches. By considering the release factors of these areas and their proportion of the entire barn, total emission rates of 371 CO2-eq. LU-1 a-1, 36 CO2-eq. LU-1 a-1, and 1.7 kg CO2-eq. LU-1 a-1 for CO2, CH4 and N2O, respectively, were measured for the whole barn surface area. The CH4 emissions from surface area were stronger climate relevant comparing to N2O emissions, but compared to CH4 emissions from slurry storage or ruminal fermentation (not measured) even insignificant.

Impacts of updated emission inventories on source apportionment of fine particle and ozone over the southeastern U.S.

NASA Astrophysics Data System (ADS)

Zhang, Yang; Wang, Wei; Wu, Shiang-Yuh; Wang, Kai; Minoura, Hiroaki; Wang, Zifa

2014-05-01

As the U.S. Environmental Protection Agency updates the National Emission Inventory (NEI), the source contributions (SC) of major source sectors to major pollutants based on source apportionment techniques should be periodically reassessed to reflect changes in SCs due to changes in emissions. This work assesses emission updates from the 1999 NEI version 2 (NEI99v2) and the 2005 NEI (NEI05) and the resulting differences in SCs using the two inventories. Large differences exist in the emissions of nitrogen oxide, formaldehyde, ammonia, terpene, and primary PM2.5 between NEI99v2 and NEI05. Differences in emissions lead to differences in model performance and source appointment. SCs of ten major source categories to fine particulate matter (PM2.5) are estimated using the Community Multiscale Air Quality modeling system with the Brute Force Method (CMAQ/BFM) andNEI05and compared with those obtained previously using CMAQ/BFM with NEI99v2. In January, compared to CMAQ/BFM (NEI99v2), CMAQ/BFM (NEI05) shows that miscellaneous areas, biomass burning, and coal combustion remain the top three contributors to PM2.5 but with different ranking and higher SCs (17.7%, 16.0%, and 14.1% for NEI05 vs. 11.8%, 13.7%, and 10.8% for NEI99v2, respectively). In July, coal combustion, miscellaneous areas, and industrial processes remain the top three with higher SCs (41.9%, 14.1%, and 8.8% for NEI05 vs.30.8%, 8.9%, and 6.9% for NEI99v2, respectively). Those changes in SCs are attributed to increased primary PM2.5 (PPM) emissions in NEI05 and increases in relative contributions of miscellaneous areas and coal combustion to the emissions of PPM, NH3, and SO2.SCs from diesel and gasoline vehicles decrease in both months, due to decreased contributions of gasoline vehicles to SO2 and NH3 emissions and those of diesel vehicles to NOx and PPM emissions. Compared with CMAQ/BFM (NEI99v2), SCs from other combustion and biomass burning are higher in Florida, due to substantial increases in formaldehyde and PPM emissions in NEI05, resulting from higher wildfire emissions and state emission updates. SCs from industrial processes increase and those from diesel and gasoline vehicles decrease in urban areas. SCs of O3 from most sources in both months increase due to a large increase in their contributions to NOx emissions, except for diesel vehicles in July, which decreases over domainwide due to a relative decrease in NOx emissions. These results provide valuable information for policy makers to formulate and adjust emission control strategies as the NEI is continuously updated.

Contribution of LPG-Derived Emissions to Air Pollution in the Metropolitan Area of Guadalajara City.

PubMed

Schifter, Isaac; Magdaleno, Moises; Díaz, Luis; Melgarejo, Luis A; Barrera, Adrian; Krüger, Burkhard; Arriaga, José L; Lopez-Salinas, Esteban

2000-10-01

Measurements of hydrocarbon (HC) emissions generated by the use of liquefied petroleum gas (LPG) in the metropolitan area of Guadalajara City (MAG) are presented in this work. Based on measurements in the course of distribution, handling, and consumption, an estimated 4407 tons/yr are released into the atmosphere. The three most important contributors to LPG emissions were refilling of LPG-fueled vehicles and commercial and domestic consumption. The MAG shows a different contribution pattern of LPG emission sources compared with that of the metropolitan area of Mexico City (MAMC). These results show that each megacity has different sources of emissions, which provides more accurate strategies in the handling procedures for LPG to decrease the impact in O 3 levels. This work represents the first evaluation performed in Guadalajara City, based on current measurements, of the LPG contribution to polluting emissions.

Contribution of LPG-derived emissions to air pollution in the metropolitan area of Guadalajara City.

PubMed

Schifter, I; Magdaleno, M; Díaz, L; Melgarejo, L A; Barrera, A; Krüger, B; Arriaga, J L; López-Salinas, E

2000-10-01

Measurements of hydrocarbon (HC) emissions generated by the use of liquefied petroleum gas (LPG) in the metropolitan area of Guadalajara City (MAG) are presented in this work. Based on measurements in the course of distribution, handling, and consumption, an estimated 4407 tons/yr are released into the atmosphere. The three most important contributors to LPG emissions were refilling of LPG-fueled vehicles and commercial and domestic consumption. The MAG shows a different contribution pattern of LPG emission sources compared with that of the metropolitan area of Mexico City (MAMC). These results show that each megacity has different sources of emissions, which provides more accurate strategies in the handling procedures for LPG to decrease the impact in O3 levels. This work represents the first evaluation performed in Guadalajara City, based on current measurements, of the LPG contribution to polluting emissions.

Characterization of VOC sources in an urban area based on PTR-MS measurements and receptor modelling.

PubMed

Stojić, A; Stojić, S Stanišić; Šoštarić, A; Ilić, L; Mijić, Z; Rajšić, S

2015-09-01

In this study, the concentrations of volatile organic compounds were measured by the use of proton transfer reaction mass spectrometry, together with NO x , NO, NO2, SO2, CO and PM10 and meteorological parameters in an urban area of Belgrade during winter 2014. The multivariate receptor model US EPA Unmix was applied to the obtained dataset resolving six source profiles, which can be attributed to traffic-related emissions, gasoline evaporation/oil refineries, petrochemical industry/biogenic emissions, aged plumes, solid-fuel burning and local laboratories. Besides the vehicle exhaust, accounting for 27.6 % of the total mixing ratios, industrial emissions, which are present in three out of six resolved profiles, exert a significant impact on air quality in the urban area. The major contribution of regional and long-range transport was determined for source profiles associated with petrochemical industry/biogenic emissions (40 %) and gasoline evaporation/oil refineries (29 %) using trajectory sector analysis. The concentration-weighted trajectory model was applied with the aim of resolving the spatial distribution of potential distant sources, and the results indicated that emission sources from neighbouring countries, as well as from Slovakia, Greece, Poland and Scandinavian countries, significantly contribute to the observed concentrations.

Mapping Emissions that Contribute to Air Pollution Using Adjoint Sensitivity Analysis

NASA Astrophysics Data System (ADS)

Bastien, L. A. J.; Mcdonald, B. C.; Brown, N. J.; Harley, R.

2014-12-01

The adjoint of the Community Multiscale Air Quality model (CMAQ) is used to map emissions that contribute to air pollution at receptors of interest. Adjoint tools provide an efficient way to calculate the sensitivity of a model response to a large number of model inputs, a task that would require thousands of simulations using a more traditional forward sensitivity approach. Initial applications of this technique, demonstrated here, are to benzene and directly-emitted diesel particulate matter, for which atmospheric reactions are neglected. Emissions of these pollutants are strongly influenced by light-duty gasoline vehicles and heavy-duty diesel trucks, respectively. We study air quality responses in three receptor areas where populations have been identified as especially susceptible to, and adversely affected by air pollution. Population-weighted air basin-wide responses for each pollutant are also evaluated for the entire San Francisco Bay area. High-resolution (1 km horizontal grid) emission inventories have been developed for on-road motor vehicle emission sources, based on observed traffic count data. Emission estimates represent diurnal, day of week, and seasonal variations of on-road vehicle activity, with separate descriptions for gasoline and diesel sources. Emissions that contribute to air pollution at each receptor have been mapped in space and time using the adjoint method. Effects on air quality of both relative (multiplicative) and absolute (additive) perturbations to underlying emission inventories are analyzed. The contributions of local versus upwind sources to air quality in each receptor area are quantified, and weekday/weekend and seasonal variations in the influence of emissions from upwind areas are investigated. The contribution of local sources to the total air pollution burden within the receptor areas increases from about 40% in the summer to about 50% in the winter due to increased atmospheric stagnation. The effectiveness of control strategies based on region-wide exposure metrics is compared with strategies that focus on improving air quality at specific receptors.

Palaeo-dust records: A window to understanding past environments

NASA Astrophysics Data System (ADS)

Marx, Samuel K.; Kamber, Balz S.; McGowan, Hamish A.; Petherick, Lynda M.; McTainsh, Grant H.; Stromsoe, Nicola; Hooper, James N.; May, Jan-Hendrik

2018-06-01

Dust entrainment, transport over vast distances and subsequent deposition is a fundamental part of the Earth system. Yet the role and importance of dust has been underappreciated, due largely to challenges associated with recognising dust in the landscape and interpreting its depositional history. Despite these challenges, interest in dust is growing. Technical advances in remote sensing and modelling have improved understanding of dust sources and production, while advances in sedimentology, mineralogy and geochemistry (in particular) have allowed dust to be more easily distinguished within sedimentary deposits. This has facilitated the reconstruction of records of dust emissions through time. A key advance in our understanding of dust has occurred following the development of methods to geochemically provenance (fingerprint) dust to its source region. This ability has provided new information on dust transport pathways, as well as the reach and impact of dust. It has also expanded our understanding of the processes driving dust emissions over decadal to millennial timescales through linking dust deposits directly to source area conditions. Dust provenance studies have shown that dust emission, transport and deposition are highly sensitive to variability in climate. They also imply that dust emissions are not simply a function of the degree of aridity in source areas, but respond to a more complex array of conditions, including sediment availability. As well as recording natural variability, dust records are also shown to sensitively track the impact of human activity. This is reflected by both changing dust emission rates and changing dust chemistry. Specific examples of how dust responds to, and records change, are provided with our work on dust emissions from Australia, the most arid inhabited continent and the largest dust source in the Southern Hemisphere. These case studies show that Australian dust emissions reflect hydro-climate variability, with reorganisation of Australian dust source areas occurring during the mid to late Holocene. Dust emissions are shown to sensitively map the structure of the Last Glacial Maximum in Australia, demonstrating that this period was associated with enhanced, but also variable dust emissions, driven by changing sources area conditions. Finally we show how dust emissions have responded to the arrival of Europeans and the associated onset of broad-scale agriculture across the Australian continent.

40 CFR 63.11407 - Am I subject to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... this subpart if you own or operate a chromium compounds manufacturing facility that is an area source... source. The affected source is each chromium compounds manufacturing facility. (1) An affected source is...

40 CFR 63.11407 - Am I subject to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... this subpart if you own or operate a chromium compounds manufacturing facility that is an area source... source. The affected source is each chromium compounds manufacturing facility. (1) An affected source is...

40 CFR 63.11407 - Am I subject to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... this subpart if you own or operate a chromium compounds manufacturing facility that is an area source... source. The affected source is each chromium compounds manufacturing facility. (1) An affected source is...

40 CFR 63.11407 - Am I subject to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... this subpart if you own or operate a chromium compounds manufacturing facility that is an area source... source. The affected source is each chromium compounds manufacturing facility. (1) An affected source is...

40 CFR 63.11407 - Am I subject to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources: Chromium... this subpart if you own or operate a chromium compounds manufacturing facility that is an area source... source. The affected source is each chromium compounds manufacturing facility. (1) An affected source is...

Radiocarbon determination of fossil and contemporary carbon contribution to aerosol in the Pacific Islands.

PubMed

Isley, C F; Nelson, P F; Taylor, M P; Williams, A A; Jacobsen, G E

2018-06-21

Combustion emissions are of growing concern across all Pacific Island Countries, which account for >10,000 km 2 of the earth's surface area; as for many other small island states globally. Apportioning emissions inputs for Suva, the largest Pacific Island city, will aid in development of emission reduction strategies. Total suspended particulate (TSP) and fine particulate (PM 2.5 ) samples were collected for Suva City, a residential area (Kinoya, TSP) and a mainly ocean-influenced site (Suva Point, TSP) from 2014 to 2015. Percentages of contemporary and fossil carbon were determined by radiocarbon analysis (accelerator mass spectrometry); for non‑carbonate carbon (NCC), elemental carbon (EC) and organic carbon (OC). Source contributions to particulate matter were identified and the accuracy of previous emissions inventory and source apportionment studies was evaluated. Suva Point NCC concentrations (2.7 ± 0.4 μg/m 3 ) were four times lower than for City (13 ± 2 μg/m 3 in TSP) and Kinoya (13 ± 1 μg/m 3 in TSP); demonstrating the contribution of land-based emissions activities in city and residential areas. In Suva City, total NCC in air was 81% (79%-83%) fossil carbon, from vehicles, shipping, power generation and industry; whilst in the residential area, 48% (46%-50%) of total NCC was contemporary carbon; reflecting the higher incidence of biomass and waste burning and of cooking activities. Secondary organic fossil carbon sources contributed >36% of NCC mass at the city and >29% at Kinoya; with biogenic carbon being Kinoya's most significant source (approx. 30% of NCC mass). These results support the previous source apportionment studies for the city area; yet show that, in line with emissions inventory studies, biomass combustion contributes more PM 2.5 mass in residential areas. Hence air quality management strategies need to target open burning activities as well as fossil fuel combustion. Copyright © 2018 Elsevier B.V. All rights reserved.

REGIONAL ASSESSMENT OF METHANE EMISSION RATES FROM RESERVOIRS IN THE MIDWESTERN UNITED STATES

EPA Science Inventory

Reservoirs are a globally significant source of methane (CH4) to the atmosphere, but regional and global emission estimates are poorly constrained due to high variability in emission rates among reservoirs and a lack of measurements in some areas geographic areas. Methane emissi...

PRELIMINARY ANALYSIS OF HAZARDOUS AIR POLLUTANT EMISSION INVENTORIES FROM THREE MAJOR URBAN AREAS

EPA Science Inventory

The paper reports EPA/AEERL's progress on emissions inventory evaluation and improvement under a hazardous air pollutant (HAP) emissions research program in support of the Urban Area Source Program required under Title III of the Clean Air Act Amendments of 1990 (CAAA). he paper ...

Emission Characterization and Emission Inventories for the 21st Century

EPA Science Inventory

Emission inventories are the foundation of cost-effective air quality management strategies. A goal of the emissions community is to develop the ultimate emission inventory which would include all significant emissions from all sources, time periods and areas, with quantified un...

SOURCE OF GENOTOXICITY AND CANCER RISK IN AMBIENT AIR

EPA Science Inventory

Products of incomplete combustion are identified as a major source of carcinogenic risk in urban areas, especially those from small non-industrial sources. he major ubiquitous emission i sources outdoors in populated areas are residential home heating and motor vehicles. olycycli...

National Emission Standards for Hazardous Air Pollutants (NESHAP) for Area Source Boilers Tune-up Guides

EPA Pesticide Factsheets

This page contains two tune-up guides for area source boilers for industrial, commercial, and institutional boilers and process heaters. The first guide is for owners and operators, and the second is for technicians for the area source boilers.

Water Pollution Prediction in the Three Gorges Reservoir Area and Countermeasures for Sustainable Development of the Water Environment

PubMed Central

Huang, Shuaijin; Qu, Xuexin

2017-01-01

The Three Gorges Project was implemented in 1994 to promote sustainable water resource use and development of the water environment in the Three Gorges Reservoir Area (hereafter “Reservoir Area”). However, massive discharge of wastewater along the river threatens these goals; therefore, this study employs a grey prediction model (GM) to predict the annual emissions of primary pollution sources, including industrial wastewater, domestic wastewater, and oily and domestic wastewater from ships, that influence the Three Gorges Reservoir Area water environment. First, we optimize the initial values of a traditional GM (1,1) model, and build a new GM (1,1) model that minimizes the sum of squares of the relative simulation errors. Second, we use the new GM (1,1) model to simulate historical annual emissions data for the four pollution sources and thereby test the effectiveness of the model. Third, we predict the annual emissions of the four pollution sources in the Three Gorges Reservoir Area for a future period. The prediction results reveal the annual emission trends for the major wastewater types, and indicate the primary sources of water pollution in the Three Gorges Reservoir Area. Based on our predictions, we suggest several countermeasures against water pollution and towards the sustainable development of the water environment in the Three Gorges Reservoir Area. PMID:29077006

METHODOLOGIES FOR ESTIMATING AIR EMISSIONS FROM THREE NON-TRADITIONAL SOURCE CATEGORIES: OIL SPILLS, PETROLEUM VESSEL LOADING & UNLOADING, AND COOLING TOWERS

EPA Science Inventory

The report discusses part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (sip) area source methodologies and to develop appropriate emis...

Example Annual Certification & Compliance Reports for Sources with and without Visible Emissions Testing: NESHAP Area Source Standards for Nine Metal Fabrication and Finishing Source Categories 40 CFR 63 Subpart XXXXXX

EPA Pesticide Factsheets

This page contains examples of the type of information that must be submitted to fulfill the Notification of Compliance Status requirement of 40 CFR 63, subpart XXXXXX for sources reporting and not reporting visible emissions information.

Stable carbon isotopes to monitor the CO2 source mix in the urban environment

NASA Astrophysics Data System (ADS)

Vogel, F. R.; Wu, L.; Ramonet, M.; Broquet, G.; Worthy, D. E. J.

2014-12-01

Urban areas are said to be responsible for approximately 71% of fossil fuel CO2 emissions while comprising only two percent of the land area [IEA, 2008]. This limited spatial expansion could facility a monitoring of anthropogenic GHGs from atmospheric observations. As major sources of emissions, cities also have a huge potential to drive emissions reductions. To effectively manage emissions, cities must however, first establish techniques to validate their reported emission statistics. A pilot study which includes continues 13CO2 data from calibrated cavity ring-down spectrometers [Vogel et al. 2013] of two "sister sites" in the vicinity of Toronto, Canada is contrasted to recent observations of 13CO2 observations in Paris during significant pollution events. Using Miller-Tans plots [Miller and Tans, 2003] for our multi-season observations reveals significant changes of the source signatures of night time CO2 emissions which reflect the importance of natural gas burning in Megacities (up to 80% of fossil fuel sources) and show-case the potential of future isotope studies to determine source sectors. Especially the winter data this approach seems suitable to determine the source contribution of different fuel types (natural gas, liquid fuels and coal) which can inform the interpretation of other Greenhouse Gases and air pollution levels.

Airborne Quantification of Methane Emissions in the San Francisco Bay Area of California

NASA Astrophysics Data System (ADS)

Guha, A.; Newman, S.; Martien, P. T.; Young, A.; Hilken, H.; Faloona, I. C.; Conley, S.

2017-12-01

The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate protection goal. The Air District maintains a regional GHG emissions inventory that includes emissions estimates and projections which influence the agency's programs and regulatory activities. The Air District is currently working to better characterize methane emissions in the GHG inventory through source-specific measurements, to resolve differences between top-down regional estimates (Fairley and Fischer, 2015; Jeong et al., 2016) and the bottom-up inventory. The Air District funded and participated in a study in Fall 2016 to quantify methane emissions from a variety of sources from an instrumented Mooney aircraft. This study included 40 hours of cylindrical vertical profile flights that combined methane and wind measurements to derive mass emission rates. Simultaneous measurements of ethane provided source-apportionment between fossil-based and biological methane sources. The facilities sampled included all five refineries in the region, five landfills, two dairy farms and three wastewater treatment plants. The calculated mass emission rates were compared to bottom-up rates generated by the Air District and to those from facility reports to the US EPA as part of the mandatory GHG reporting program. Carbon dioxide emission rates from refineries are found to be similar to bottom-up estimates for all sources, supporting the efficacy of the airborne measurement methodology. However, methane emission estimates from the airborne method showed significant differences for some source categories. For example, methane emission estimates based on airborne measurements were up to an order of magnitude higher for refineries, and up to five times higher for landfills compared to bottom-up methods, suggesting significant underestimation in the inventories and self-reported estimates. Future measurements over the same facilities will reveal if we have seasonal and process-dependent trends in emissions. This will provide a basis for rule making and for designing mitigation and control actions.

Wet nitrogen deposition across the urban-intensive agricultural-rural transect of a small urban area in southwest China.

PubMed

Deng, Ouping; Zhang, Shirong; Deng, Liangji; Zhang, Chunlong; Fei, Jianbo

2018-03-01

Understanding of the spatial and temporal variation of the flux of atmospheric nitrogen (N) deposition is essential for assessment of its impact on ecosystems. However, little attention has been paid to the variability of N deposition across urban-intensive agricultural-rural transects. A continuous 2-year observational study (from January 2015 to December 2016) was conducted to determine wet N deposition across the urban-intensive agricultural-rural transect of a small urban area in southwest China. Significantly spatial and temporal variations were found in the research area. Along the urban-intensive agricultural-rural transect, the TN and NH 4 + -N deposition first increased and then decreased, and the NO 3 - -N and dissolved organic N (DON) deposition decreased continuously. Wet N deposition was mainly affected by the districts of agro-facilities, roads and build up lands. Wet NH 4 + -N deposition had non-seasonal emission sources including industrial emissions and urban excretory wastes in urban districts and seasonal emission sources such as fertilizer and manure volatilization in the other districts. However, wet NO 3 - -N deposition had seasonal emission sources such as industrial emissions and fireworks in urban district and non-seasonal emission sources such as transportation in the other districts. Deposition of DON was likely to have had similar sources to NO 3 - -N deposition in rural district, and high-temperature-dependent sources in urban and intensive agricultural districts. Considering the annual wet TN deposition in the intensive agricultural district was about 11.1% of the annual N fertilizer input, N fertilizer rates of crops should be reduced in this region to avoid the excessive application, and the risk of N emissions to the environment.

Eagle Ford Shale BTEX and NOx concentrations are dominated by oil and gas industry emissions

NASA Astrophysics Data System (ADS)

Schade, G. W.; Roest, G. S.

2017-12-01

US shale oil and gas exploration has been identified as a major source of greenhouse gases and non-methane hydrocarbon (NMHC) emissions to the atmosphere. Here, we present a detailed analysis of 2015 air quality data acquired by the Texas Commission on Environmental Quality (TCEQ) at an air quality monitoring station in Karnes County, TX, central to Texas' Eagle Ford shale area. Data include time series of hourly measured NMHCs, nitrogen oxides (NOx), and hydrogen sulfide (H2S) alongside meteorological measurements. The monitor was located in Karnes City, and thus affected by various anthropogenic emissions, including traffic and oil and gas exploration sources. Highest mixing ratios measured in 2015 included nearly 1 ppm ethane, 0.8 ppm propane, alongside 4 ppb benzene. A least-squares minimization non-negative matrix factorization (NMF) analysis, tested with prior data analyzed using standard PMF-2 software, showed six major emission sources: an evaporative and fugitive source, a flaring source, a traffic source, an oil field source, a diesel source, and an industrial manufacturing source, together accounting for more than 95% of data set variability, and interpreted using NMHC composition and meteorological data. Factor scores strongly suggest that NOx emissions are dominated by flaring and associated sources, such as diesel compressor engines, likely at midstream facilities, while traffic in this rural area is a minor NOx source. The results support, but exceed existing 2012 emission inventories estimating that local traffic emitted seven times fewer NOx than oil and gas exploration sources in the county. Sources of air toxics such as the BTEX compounds are also dominated by oil and gas exploration sources, but are more equally distributed between the associated factors. Benzene abundance is only 20-40% associated with traffic sources, and may thus be 2.5-5 times higher now than prior to the shale boom in this area. Although the monitor was located relatively far from oil and gas exploration sources, these results suggest that exposure to air toxics in this rural population has likely increased manifold since the start of the regional shale boom in 2008.

Characterization of methane emissions in Los Angeles with airborne hyperspectral imaging

NASA Astrophysics Data System (ADS)

Saad, K.; Tratt, D. M.; Buckland, K. N.; Roehl, C. M.; Wennberg, P. O.; Wunch, D.

2017-12-01

As urban areas develop regulations to limit atmospheric methane (CH4), accurate quantification of anthropogenic emissions will be critical for program development and evaluation. However, relating emissions derived from process-level metadata to those determined from assimilating atmospheric observations of CH4 concentrations into models is particularly difficult. Non-methane hydrocarbons (NMHCs) can help differentiate between thermogenic and biogenic CH4 emissions, as they are primarily co-emitted with the former; however, these trace gases are subject to the same limitations as CH4. Remotely-sensed hyperspectral imaging bridges these approaches by measuring emissions plumes directly with spatial coverage on the order of 10 km2 min-1. We identify the sources of and evaluate emissions plumes measured by airborne infrared hyperspectral imagers flown over the Los Angeles (LA) metropolitan area, which encompasses various CH4 sources, including petroleum and natural gas wells and facilities. We quantify total CH4 and NMHC emissions, as well as their relative column densities, at the point-source level to create fingerprints of source types. We aggregate these analyses to estimate the range of variability in chemical composition across source types. These CH4 and NMHC emissions factors are additionally compared to their tropospheric column abundances measured by the Total Carbon Column Observing Network (TCCON) Pasadena Fourier transform infrared spectrometer, which provides a footprint for the LA basin.

The importance of policy in emissions inventory accuracy--a lesson from British Columbia, Canada.

PubMed

Krzyzanowski, Judi

2009-04-01

Actual atmospheric emissions in northeast British Columbia, Canada, are much higher than reported emissions. The addition of upstream oil and gas sector sources not included in the year-2000 emissions inventory of Criteria Air Contaminants (CACs) increases annual totals of nitrogen oxides, sulfur oxides, and volatile organic compound emissions by 115.1, 89.9, and 109.5%, respectively. These emissions arise from numerous small and unregulated point sources (N = 10,129). CAC summaries are given by source type and source sector. An analysis of uncertainty and reporting policy suggests that inventory omissions are not limited to the study area and that Canadian pollutant emissions are systematically underestimated. The omissions suggest that major changes in reporting procedures are needed in Canada if true estimates of annual pollutant emissions are to be documented.

The importance of source configuration in quantifying footprints of regional atmospheric sulphur deposition.

PubMed

Vieno, M; Dore, A J; Bealey, W J; Stevenson, D S; Sutton, M A

2010-01-15

An atmospheric transport-chemistry model is applied to investigate the effects of source configuration in simulating regional sulphur deposition footprints from elevated point sources. Dry and wet depositions of sulphur are calculated for each of the 69 largest point sources in the UK. Deposition contributions for each point source are calculated for 2003, as well as for a 2010 emissions scenario. The 2010 emissions scenario has been chosen to simulate the Gothenburg protocol emission scenario. Point source location is found to be a major driver of the dry/wet deposition ratio for each deposition footprint, with increased precipitation scavenging of SO(x) in hill areas resulting in a larger fraction of the emitted sulphur being deposited within the UK for sources located near these areas. This reduces exported transboundary pollution, but, associated with the occurrence of sensitive soils in hill areas, increases the domestic threat of soil acidification. The simulation of plume rise using individual stack parameters for each point source demonstrates a high sensitivity of SO(2) surface concentration to effective source height. This emphasises the importance of using site-specific information for each major stack, which is rarely included in regional atmospheric pollution models, due to the difficulty in obtaining the required input data. The simulations quantify how the fraction of emitted SO(x) exported from the UK increases with source magnitude, effective source height and easterly location. The modelled reduction in SO(x) emissions, between 2003 and 2010 resulted in a smaller fraction being exported, with the result that the reductions in SO(x) deposition to the UK are less than proportionate to the emission reduction. This non-linearity is associated with a relatively larger fraction of the SO(2) being converted to sulphate aerosol for the 2010 scenario, in the presence of ammonia. The effect results in less-than-proportional UK benefits of reducing in SO(2) emissions, together with greater-than-proportional benefits in reducing export of UK SO(2) emissions. Copyright 2009 Elsevier B.V. All rights reserved.

40 CFR 63.1218 - What are the standards for hydrochloric acid production furnaces that burn hazardous waste?

Code of Federal Regulations, 2013 CFR

2013-07-01

... limits provided by paragraph (a)(5) of this section; (2) For mercury, hydrogen chloride and chlorine gas..., except for an area source as defined under § 63.2, hydrogen chloride and chlorine gas emissions in excess..., except for an area source as defined under § 63.2, hydrogen chloride and chlorine gas emissions in excess...

High resolution of black carbon and organic carbon emissions in the Pearl River Delta region, China.

PubMed

Zheng, Junyu; He, Min; Shen, Xingling; Yin, Shasha; Yuan, Zibing

2012-11-01

A high-resolution regional black carbon (BC) and organic carbon (OC) emission inventory for the year 2009 was developed for the Pearl River Delta (PRD) region, China, based on the collected activity data and the latest emission factors. PM(2.5), BC and OC emissions were estimated to be 303 kt, 39 kt and 31 kt, respectively. Industrial processes were major contributing sources to PM(2.5) emissions. BC emissions were mainly from mobile sources, accounting for 65.0%, while 34.1% of OC emissions were from residential combustion. The primary OC/BC ratios for individual cities in the PRD region were dependent on the levels of economic development due to differences in source characteristics, with high ratios in the less developed cities and low ratios in the central and southern developed areas. The preliminary temporal profiles were established, showing the highest OC emissions in winter and relatively constant BC emissions throughout the year. The emissions were spatially allocated into grid cells with a resolution of 3 km × 3 km. Large amounts of BC emissions were distributed over the central-southern PRD city clusters, while OC emissions exhibited a relatively even spatial distribution due to the significant biomass burning emissions from the outlying area of the PRD region. Uncertainties in carbonaceous aerosol emissions were usually higher than in other primary pollutants like SO(2), NO(x), and PM(10). One of the key uncertainty sources was the emission factor, due to the absence of direct measurements of BC and OC emission rates. Copyright © 2012 Elsevier B.V. All rights reserved.

Will urban expansion lead to an increase in future water pollution loads?--a preliminary investigation of the Haihe River Basin in northeastern China.

PubMed

Dong, Yang; Liu, Yi; Chen, Jining

2014-01-01

Urban expansion is a major driving force changing regional hydrology and nonpoint source pollution. The Haihe River Basin, the political, economic, and cultural center of northeastern China, has undergone rapid urbanization in recent decades. To investigate the consequences of future urban sprawl on nonpoint source water pollutant emissions in the river basin, the urban sprawl in 2030 was estimated, and the annual runoff and nonpoint source pollution in the Haihe River basin were simulated. The Integrated Model of Non-Point Sources Pollution Processes (IMPULSE) was used to simulate the effects of urban sprawl on nonpoint source pollution emissions. The outcomes indicated that the urban expansion through 2030 increased the nonpoint source total nitrogen (TN), total phosphorous (TP), and chemical oxygen demand (COD) emissions by 8.08, 0.14, and 149.57 kg/km(2), respectively. Compared to 2008, the total nonpoint emissions rose by 15.33, 0.57, and 12.39 %, respectively. Twelve percent of the 25 cities in the basin would increase by more than 50 % in nonpoint source TN and COD emissions in 2030. In particular, the nonpoint source TN emissions in Xinxiang, Jiaozuo, and Puyang would rise by 73.31, 67.25, and 58.61 %, and the nonpoint source COD emissions in these cities would rise by 74.02, 51.99, and 53.27 %, respectively. The point source pollution emissions in 2008 and 2030 were also estimated to explore the effects of urban sprawl on total water pollution loads. Urban sprawl through 2030 would bring significant structural changes of total TN, TP, and COD emissions for each city in the area. The results of this study could provide insights into the effects of urbanization in the study area and the methods could help to recognize the role that future urban sprawl plays in the total water pollution loads in the water quality management process.

Method to establish the emission inventory of anthropogenic volatile organic compounds in China and its application in the period 2008-2012

NASA Astrophysics Data System (ADS)

Wu, Rongrong; Bo, Yu; Li, Jing; Li, Lingyu; Li, Yaqi; Xie, Shaodong

2016-02-01

A method was developed to establish a comprehensive anthropogenic VOC emission inventory in China, in which a four-level source categorization was proposed, and an emission factor determination system together with a reference database were developed. And this was applied to establish VOC emission inventories for the period 2008-2012. Results show China's anthropogenic VOC emissions increased from 22.45 Tg in 2008 to 29.85 Tg in 2012 at an annual average rate of 7.38%, with Shandong, Guangdong, Jiangsu, Zhejiang and Hebei provinces being the largest emitters. Industrial processes, transportation and solvent utilization were the key sources, accounting for 39.3%, 25.6%, and 14.9% of the total emissions in 2012, respectively. Passenger cars, biofuel combustion, coke production, field burning of biomass, and raw chemical manufacturing were the primary VOC sources nationwide. The key sources for each province were different because of the disparate industry and energy structure. China's VOC emissions displayed remarkable spatial variation, with emissions in the east and southeast regions being much larger than in the northwest, and the high emission areas mainly centered in the Bohai Economic Rim, the Yangtze River Delta, the Pearl River Delta and the Sichuan Basin. The size of high emission areas expanded over the period 2008-2012, with heavily polluted city clusters gradually emerging.

The Hestia Project: High Spatial Resolution Fossil Fuel Carbon Dioxide Emissions Quantification at Hourly Scale in Indianapolis, USA

NASA Astrophysics Data System (ADS)

Zhou, Y.; Gurney, K. R.

2009-12-01

In order to advance the scientific understanding of carbon exchange with the land surface and contribute to sound, quantitatively-based U.S. climate change policy interests, quantification of greenhouse gases emissions drivers at fine spatial and temporal scales is essential. Quantification of fossil fuel CO2 emissions, the primary greenhouse gases, has become a key component to cost-effective CO2 emissions mitigation options and a carbon trading system. Called the ‘Hestia Project’, this pilot study generated CO2 emissions down to high spatial resolution and hourly scale for the greater Indianapolis region in the USA through the use of air quality and traffic monitoring data, remote sensing, GIS, and building energy modeling. The CO2 emissions were constructed from three data source categories: area, point, and mobile. For the area source emissions, we developed an energy consumption model using DOE/EIA survey data on building characteristics and energy consumption. With the Vulcan Project’s county-level CO2 emissions and simulated building energy consumption, we quantified the CO2 emissions for each individual building by allocating Vulcan emissions to roughly 50,000 structures in Indianapolis. The temporal pattern of CO2 emissions in each individual building was developed based on temporal patterns of energy consumption. The point sources emissions were derived from the EPA National Emissions Inventory data and effluent monitoring of electricity producing facilities. The mobile source CO2 emissions were estimated at the month/county scale using the Mobile6 combustion model and the National Mobile Inventory Model database. The month/county scale mobile source CO2 emissions were downscaled to the “native” spatial resolution of road segments every hour using a GIS road atlas and traffic monitoring data. The result is shown in Figure 1. The resulting urban-scale inventory can serve as a baseline of current CO2 emissions and should be of immediate use to city environmental managers and regional industry as they plan emission mitigation options and project future emission trends. The results obtained here will also be a useful comparison to atmospheric CO2 monitoring efforts from the top-down. Figure 1. Location of the study area, the building level and mobile CO2 emissions, and an enlarged example neighborhood

Sources of nitrogen and phosphorus emissions to Irish rivers and coastal waters: Estimates from a nutrient load apportionment framework.

PubMed

Mockler, Eva M; Deakin, Jenny; Archbold, Marie; Gill, Laurence; Daly, Donal; Bruen, Michael

2017-12-01

More than half of surface water bodies in Europe are at less than good ecological status according to Water Framework Directive assessments, and diffuse pollution from agriculture remains a major, but not the only, cause of this poor performance. Agri-environmental policy and land management practices have, in many areas, reduced nutrient emissions to water. However, additional measures may be required in Ireland to further decouple the relationship between agricultural productivity and emissions to water, which is of vital importance given on-going agricultural intensification. The Source Load Apportionment Model (SLAM) framework characterises sources of phosphorus (P) and nitrogen (N) emissions to water at a range of scales from sub-catchment to national. The SLAM synthesises land use and physical characteristics to predict emissions from point (wastewater, industry discharges and septic tank systems) and diffuse sources (agriculture, forestry, etc.). The predicted annual nutrient emissions were assessed against monitoring data for 16 major river catchments covering 50% of the area of Ireland. At national scale, results indicate that total average annual emissions to surface water in Ireland are over 2700tyr -1 of P and 82,000tyr -1 of N. The proportional contributions from individual sources show that the main sources of P are from municipal wastewater treatment plants and agriculture, with wide variations across the country related to local anthropogenic pressures and the hydrogeological setting. Agriculture is the main source of N emissions to water across all regions of Ireland. These policy-relevant results synthesised large amounts of information in order to identify the dominant sources of nutrients at regional and local scales, contributing to the national nutrient risk assessment of Irish water bodies. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

NASA Astrophysics Data System (ADS)

Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; Loewenstein, Max; Tadić, Jovan M.; Wecht, Kevin J.; Jeong, Seongeun; Fischer, Marc L.

2014-12-01

This study analyzes source apportioned methane (CH4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were ∼5.30 Gg day-1 (Gg = 1.0 × 109 g) (equating to ∼1.90 × 103 Gg yr-1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ∼30% of total CH4 emissions from California. Source apportionment analysis during this study shows that CH4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 mixing ratios in northern California (average normalized mean bias (NMB) = -5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH4 were measured over local emission sources and atmospheric CH4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California.

Analyzing Source Apportioned Methane in Northern California During DISCOVER-AQ-CA Using Airborne Measurements and Model Simulations

NASA Technical Reports Server (NTRS)

Johnson, Matthew S.

2014-01-01

This study analyzes source apportioned methane (CH4) emissions and atmospheric concentrations in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH4 emissions were 5.30 Gg/day (Gg 1.0 109 grams) (equating to 1.9 103 Gg/yr) for all of California. According to EDGAR, the SFBA and northern SJV region contributes 30 of total emissions from California. Source apportionment analysis during this study shows that CH4 concentrations over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH4 concentrations in northern California (average normalized mean bias (NMB) -5 and linear regression slope 0.25). The largest negative biases in the model were calculated on days when hot spots of local emission sources were measured and atmospheric CH4 concentrations reached values 3.0 parts per million (model NMB -10). Sensitivity emission studies conducted during this research suggest that local emissions of CH4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH4 emissions in California and further the understanding of the physical processes controlling them.

Analyzing source apportioned methane in northern California during Discover-AQ-CA using airborne measurements and model simulations

DOE PAGES

Johnson, Matthew S.; Yates, Emma L.; Iraci, Laura T.; ...

2014-12-01

This study analyzes source apportioned methane (CH 4) emissions and atmospheric mixing ratios in northern California during the Discover-AQ-CA field campaign using airborne measurement data and model simulations. Source apportioned CH 4 emissions from the Emissions Database for Global Atmospheric Research (EDGAR) version 4.2 were applied in the 3-D chemical transport model GEOS-Chem and analyzed using airborne measurements taken as part of the Alpha Jet Atmospheric eXperiment over the San Francisco Bay Area (SFBA) and northern San Joaquin Valley (SJV). During the time period of the Discover-AQ-CA field campaign EDGAR inventory CH 4 emissions were ~5.30 Gg day –1 (Ggmore » = 1.0 × 10 9 g) (equating to ~1.90 × 10 3 Gg yr –1) for all of California. According to EDGAR, the SFBA and northern SJV region contributes ~30% of total CH 4 emissions from California. Source apportionment analysis during this study shows that CH 4 mixing ratios over this area of northern California are largely influenced by global emissions from wetlands and local/global emissions from gas and oil production and distribution, waste treatment processes, and livestock management. Model simulations, using EDGAR emissions, suggest that the model under-estimates CH 4 mixing ratios in northern California (average normalized mean bias (NMB) = –5.2% and linear regression slope = 0.20). The largest negative biases in the model were calculated on days when large amounts of CH 4 were measured over local emission sources and atmospheric CH 4 mixing ratios reached values >2.5 parts per million. Sensitivity emission studies conducted during this research suggest that local emissions of CH 4 from livestock management processes are likely the primary source of the negative model bias. These results indicate that a variety, and larger quantity, of measurement data needs to be obtained and additional research is necessary to better quantify source apportioned CH 4 emissions in California.« less

Emissions of CO2 and criteria air pollutants from mobile sources: Insights from integrating real-time traffic data into local air quality models

NASA Astrophysics Data System (ADS)

Gately, Conor; Hutyra, Lucy

2016-04-01

In 2013, on-road mobile sources were responsible for over 26% of U.S. fossil fuel carbon dioxide (ffCO2) emissions, and over 34% of both CO and NOx emissions. However, accurate representations of these emissions at the scale of urban areas remains a difficult challenge. Quantifying emissions at the scale of local streets and highways is critical to provide policymakers with the information needed to develop appropriate mitigation strategies and to guide research into the underlying process that drive mobile emissions. Quantification of vehicle ffCO2 emissions at high spatial and temporal resolutions requires a detailed synthesis of data on traffic activity, roadway attributes, fleet characteristics and vehicle speeds. To accurately characterize criteria air pollutant emissions, information on local meteorology is also critical, as the temperature and relative humidity can affect emissions rates of these pollutants by as much as 400%. As the health impacts of air pollutants are more severe for residents living in close proximity (<500m) to road sources, it is critical that inventories of these emissions rely on highly resolved source data to locate potential hot-spots of exposure. In this study we utilize real-time GPS estimates of vehicle speeds to estimate ffCO2 and criteria air pollutant emissions at multiple spatial and temporal scales across a large metropolitan area. We observe large variations in emissions associated with diurnal activity patterns, congestion, sporting and civic events, and weather anomalies. We discuss the advantages and challenges of using highly-resolved source data to quantify emissions at a roadway scale, and the potential of this methodology for forecasting the air quality impacts of changes in infrastructure, urban planning policies, and regional climate.

Emissions of CO2 and criteria air pollutants from mobile sources: Insights from integrating real-time traffic data into local air quality models

NASA Astrophysics Data System (ADS)

Gately, C.; Hutyra, L.; Sue Wing, I.; Peterson, S.; Janetos, A.

2015-12-01

In 2013, on-road mobile sources were responsible for over 26% of U.S. fossil fuel carbon dioxide (ffCO2) emissions, and over 34% of both CO and NOx emissions. However, accurate representations of these emissions at the scale of urban areas remains a difficult challenge. Quantifying emissions at the scale of local streets and highways is critical to provide policymakers with the information needed to develop appropriate mitigation strategies and to guide research into the underlying process that drive mobile emissions. Quantification of vehicle ffCO2 emissions at high spatial and temporal resolutions requires a detailed synthesis of data on traffic activity, roadway attributes, fleet characteristics and vehicle speeds. To accurately characterize criteria air pollutant emissions, information on local meteorology is also critical, as the temperature and relative humidity can affect emissions rates of these pollutants by as much as 400%. As the health impacts of air pollutants are more severe for residents living in close proximity (<500m) to road sources, it is critical that inventories of these emissions rely on highly resolved source data to locate potential hot-spots of exposure. In this study we utilize real-time GPS estimates of vehicle speeds to estimate ffCO2 and criteria air pollutant emissions at multiple spatial and temporal scales across a large metropolitan area. We observe large variations in emissions associated with diurnal activity patterns, congestion, sporting and civic events, and weather anomalies. We discuss the advantages and challenges of using highly-resolved source data to quantify emissions at a roadway scale, and the potential of this methodology for forecasting the air quality impacts of changes in infrastructure, urban planning policies, and regional climate.

Developing Particle Emission Inventories Using Remote Sensing (PEIRS)

NASA Technical Reports Server (NTRS)

Tang, Chia-Hsi; Coull, Brent A.; Schwartz, Joel; Lyapustin, Alexei I.; Di, Qian; Koutrakis, Petros

2016-01-01

Information regarding the magnitude and distribution of PM(sub 2.5) emissions is crucial in establishing effective PM regulations and assessing the associated risk to human health and the ecosystem. At present, emission data is obtained from measured or estimated emission factors of various source types. Collecting such information for every known source is costly and time consuming. For this reason, emission inventories are reported periodically and unknown or smaller sources are often omitted or aggregated at large spatial scale. To address these limitations, we have developed and evaluated a novel method that uses remote sensing data to construct spatially-resolved emission inventories for PM(sub 2.5). This approach enables us to account for all sources within a fixed area, which renders source classification unnecessary. We applied this method to predict emissions in the northeast United States during the period of 2002-2013 using high- resolution 1 km x 1 km Aerosol Optical Depth (AOD). Emission estimates moderately agreed with the EPA National Emission Inventory (R(sup2) = 0.66 approx. 0.71, CV = 17.7 approx. 20%). Predicted emissions are found to correlate with land use parameters suggesting that our method can capture emissions from land use-related sources. In addition, we distinguished small-scale intra-urban variation in emissions reflecting distribution of metropolitan sources. In essence, this study demonstrates the great potential of remote sensing data to predict particle source emissions cost-effectively.

Developing Particle Emission Inventories Using Remote Sensing (PEIRS)

PubMed Central

Tang, Chia-Hsi; Coull, Brent A.; Schwartz, Joel; Lyapustin, Alexei I.; Di, Qian; Koutrakis, Petros

2018-01-01

Information regarding the magnitude and distribution of PM2.5 emissions is crucial in establishing effective PM regulations and assessing the associated risk to human health and the ecosystem. At present, emission data is obtained from measured or estimated emission factors of various source types. Collecting such information for every known source is costly and time consuming. For this reason, emission inventories are reported periodically and unknown or smaller sources are often omitted or aggregated at large spatial scale. To address these limitations, we have developed and evaluated a novel method that uses remote sensing data to construct spatially-resolved emission inventories for PM2.5. This approach enables us to account for all sources within a fixed area, which renders source classification unnecessary. We applied this method to predict emissions in the northeast United States during the period of 2002–2013 using high- resolution 1 km × 1km Aerosol Optical Depth (AOD). Emission estimates moderately agreed with the EPA National Emission Inventory (R2=0.66~0.71, CV = 17.7~20%). Predicted emissions are found to correlate with land use parameters suggesting that our method can capture emissions from land use-related sources. In addition, we distinguished small-scale intra-urban variation in emissions reflecting distribution of metropolitan sources. In essence, this study demonstrates the great potential of remote sensing data to predict particle source emissions cost-effectively. PMID:27653469

40 CFR 63.11623 - What are the testing requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... of the cyclone, dry basis, corrected to standard conditions, g/min; MOUTLET = Mass of particulate... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Prepared Feeds...

High-resolution atmospheric emission inventory of the argentine energy sector. Comparison with edgar global emission database.

PubMed

Puliafito, S Enrique; Allende, David G; Castesana, Paula S; Ruggeri, Maria F

2017-12-01

This study presents a 2014 high-resolution spatially disaggregated emission inventory (0.025° × 0.025° horizontal resolution), of the main activities in the energy sector in Argentina. The sub-sectors considered are public generation of electricity, oil refineries, cement production, transport (maritime, air, rail and road), residential and commercial. The following pollutants were included: greenhouse gases (CO 2 , CH 4 , N 2 O), ozone precursors (CO, NOx, VOC) and other specific air quality indicators such as SO 2 , PM10, and PM2.5. This work could contribute to a better geographical allocation of the pollutant sources through census based population maps. Considering the sources of greenhouse gas emissions, the total amount is 144 Tg CO2eq, from which the transportation sector emits 57.8 Tg (40%); followed by electricity generation, with 40.9 Tg (28%); residential + commercial, with 31.24 Tg (22%); and cement and refinery production, with 14.3 Tg (10%). This inventory shows that 49% of the total emissions occur in rural areas: 31% in rural areas of medium population density, 13% in intermediate urban areas and 7% in densely populated urban areas. However, if emissions are analyzed by extension (per square km), the largest impact is observed in medium and densely populated urban areas, reaching more than 20.3 Gg per square km of greenhouse gases, 297 Mg/km 2 of ozone precursors gases and 11.5 Mg/km 2 of other air quality emissions. A comparison with the EDGAR global emission database shows that, although the total country emissions are similar for several sub sectors and pollutants, its spatial distribution is not applicable to Argentina. The road and residential transport emissions represented by EDGAR result in an overestimation of emissions in rural areas and an underestimation in urban areas, especially in more densely populated areas. EDGAR underestimates 60 Gg of methane emissions from road transport sector and fugitive emissions from refining activities.

78 FR 37164 - Revisions to the Air Emissions Reporting Requirements: Revisions to Lead (Pb) Reporting Threshold...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-20

...Today's action proposes changes to the existing EPA emission inventory reporting requirements on state, local, and tribal agencies in the current Air Emissions Reporting Requirements rule published on December 17, 2008. The proposed amendments would lower the current threshold for reporting Pb sources as point sources; eliminate the requirement for reporting emissions from wildfires and prescribed fires; and replace a requirement for reporting mobile source emissions with a requirement for reporting the input parameters that can be used to run the EPA models that generate the emissions estimates. In addition, the proposed amendments would reduce the reporting burden on state, local, and tribal agencies by removing the requirements to report daily and seasonal emissions associated with carbon monoxide (CO), ozone (O3), and particulate matter up to 10 micrometers in size (PM10) nonattainment areas and nitrogen oxides (NOX) State Implementation Plan (SIP) call areas, although reporting requirements for those emissions would remain in other regulations. Lastly, the proposed amendments would clarify, remove, or simplify some current emissions reporting requirements which we believe are not necessary or are not clearly aligned with current inventory terminology and practices.

Electrohydrodynamically driven large-area liquid ion sources

DOEpatents

Pregenzer, Arian L.

1988-01-01

A large-area liquid ion source comprises means for generating, over a large area of the surface of a liquid, an electric field of a strength sufficient to induce emission of ions from a large area of said liquid. Large areas in this context are those distinct from emitting areas in unidimensional emitters.

Source Characterization of Volatile Organic Compounds Affecting the Air Quality in a Coastal Urban Area of South Texas

PubMed Central

Sanchez, Marciano; Karnae, Saritha; John, Kuruvilla

2008-01-01

Selected Volatile Organic Compounds (VOC) emitted from various anthropogenic sources including industries and motor vehicles act as primary precursors of ozone, while some VOC are classified as air toxic compounds. Significantly large VOC emission sources impact the air quality in Corpus Christi, Texas. This urban area is located in a semi-arid region of South Texas and is home to several large petrochemical refineries and industrial facilities along a busy ship-channel. The Texas Commission on Environmental Quality has setup two continuous ambient monitoring stations (CAMS 633 and 634) along the ship channel to monitor VOC concentrations in the urban atmosphere. The hourly concentrations of 46 VOC compounds were acquired from TCEQ for a comprehensive source apportionment study. The primary objective of this study was to identify and quantify the sources affecting the ambient air quality within this urban airshed. Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS) was applied to the dataset. PCA identified five possible sources accounting for 69% of the total variance affecting the VOC levels measured at CAMS 633 and six possible sources affecting CAMS 634 accounting for 75% of the total variance. APCS identified natural gas emissions to be the major source contributor at CAMS 633 and it accounted for 70% of the measured VOC concentrations. The other major sources identified at CAMS 633 included flare emissions (12%), fugitive gasoline emissions (9%), refinery operations (7%), and vehicle exhaust (2%). At CAMS 634, natural gas sources were identified as the major source category contributing to 31% of the observed VOC. The other sources affecting this site included: refinery operations (24%), flare emissions (22%), secondary industrial processes (12%), fugitive gasoline emissions (8%) and vehicle exhaust (3%). PMID:19139530

Eddy Covariance Measurements of Methane Emissions from a Dairy Farm Waste Lagoon

NASA Astrophysics Data System (ADS)

Sokol, A. B.; Lauvaux, T.; Richardson, S.; Hlywiak, J.; Davis, K. J.; Hristov, A. N.

2016-12-01

Livestock manure management in dairy operations is a known source of methane (CH4), a potent greenhouse gas. Anaerobic waste lagoons are a common manure management technique; thus, their associated CH4 emissions are relevant to national greenhouse gas inventories and local air quality. Our objective was to characterize the variability of summertime CH4 emissions from a lagoon at a dairy facility in central Pennsylvania. Continuous flux measurements were taken over two weeks in July using the eddy covariance method, which uses high-frequency gas concentration and three-dimensional wind speed measurements to calculate turbulent fluxes from a source area. After data filtration based on turbulence characteristics and source area, the average CH4 flux density from the lagoon was estimated to be 99 μmol m-2 s-1. This implies daily lagoon emissions of 881 kg CH4, corresponding to an average emission rate of 340 g CH4 per cow per day. We observed no apparent relationship between emissions and air temperature or relative humidity, though an extended measurement period is needed to better quantify the relationship that is expected to exist between air and/or slurry temperature and CH4 flux. Our measured per-area emission rate is toward the high end of the range of estimates found in the literature. These results contribute to greenhouse gas inventory development and could have important implications for emission mitigation strategies.

Quantifying Uncontrolled Air Emissions from Two Florida Landfills

EPA Science Inventory

Landfill gas emissions, if left uncontrolled, contribute to air toxics, climate change, trospospheric ozone, and urban smog. Measuring emissions from landfills presents unique challenges due to the large and variable source area, spatial and temporal variability of emissions, and...

REVIEW AND EVALUATION OF CURRENT METHODS AND USER NEEDS FOR OTHER STATIONARY COMBUSTION SOURCES

EPA Science Inventory

The report gives results of Phase 1 of an effort to develop improved methodologies for estimating area source emissions of air pollutants from stationary combustion sources. The report (1) evaluates Area and Mobile Source (AMS) subsystem methodologies; (2) compares AMS results w...

Heavy metal transport in large river systems: heavy metal emissions and loads in the Rhine and Elbe river basins

NASA Astrophysics Data System (ADS)

Vink, Rona; Behrendt, Horst

2002-11-01

Pollutant transport and management in the Rhine and Elbe basins is still of international concern, since certain target levels set by the international committees for protection of both rivers have not been reached. The analysis of the chain of emissions of point and diffuse sources to river loads will provide policy makers with a tool for effective management of river basins. The analysis of large river basins such as the Elbe and Rhine requires information on the spatial and temporal characteristics of both emissions and physical information of the entire river basin. In this paper, an analysis has been made of heavy metal emissions from various point and diffuse sources in the Rhine and Elbe drainage areas. Different point and diffuse pathways are considered in the model, such as inputs from industry, wastewater treatment plants, urban areas, erosion, groundwater, atmospheric deposition, tile drainage, and runoff. In most cases the measured heavy metal loads at monitoring stations are lower than the sum of the heavy metal emissions. This behaviour in large river systems can largely be explained by retention processes (e.g. sedimentation) and is dependent on the specific runoff of a catchment. Independent of the method used to estimate emissions, the source apportionment analysis of observed loads was used to determine the share of point and diffuse sources in the heavy metal load at a monitoring station by establishing a discharge dependency. The results from both the emission analysis and the source apportionment analysis of observed loads were compared and gave similar results. Between 51% (for Hg) and 74% (for Pb) of the total transport in the Elbe basin is supplied by inputs from diffuse sources. In the Rhine basin diffuse source inputs dominate the total transport and deliver more than 70% of the total transport. The diffuse hydrological pathways with the highest share are erosion and urban areas.

Source apportionment of surface ozone in the Yangtze River Delta, China in the summer of 2013

NASA Astrophysics Data System (ADS)

Li, L.; An, J. Y.; Shi, Y. Y.; Zhou, M.; Yan, R. S.; Huang, C.; Wang, H. L.; Lou, S. R.; Wang, Q.; Lu, Q.; Wu, J.

2016-11-01

We applied ozone source apportionment technology (OSAT) with tagged tracers coupled within the Comprehensive Air Quality Model with Extensions (CAMx) to study the region and source category contribution to surface ozone in the Yangtze River Delta area in summer of 2013. Results indicate that the daytime ozone concentrations in the YRD region are influenced by emissions both locally, regionally and super-regionally. At urban Shanghai, Hangzhou and Suzhou receptors, the ozone formation is mainly VOC-limited, precursor emissions form Zhejiang province dominate their O3 concentrations. At the junction area among two provinces and Shanghai city, the ozone is usually influenced by all the three areas. The daily max O3 at the Dianshan Lake in July are contributed by Zhejiang (48.5%), Jiangsu (11.7%), Anhui (11.6%) and Shanghai (7.4%), long-range transport constitutes around 20.9%. At Chongming site, the BVOC emissions rate is higher than urban region. Regional contribution results show that Shanghai constitutes 15.6%, Jiangsu contributes 16.2% and Zhejiang accounts for 25.5% of the daily max O3. The analysis of the source category contribution to high ozone in the Yangtze River Delta region indicates that the most significant anthropogenic emission source sectors contributing to O3 pollution include industry, vehicle exhaust, although the effects vary with source sector and selected pollution episodes. Emissions of NOx and VOCs emitted from the fuel combustion of industrial boilers and kilns, together with VOCs emissions from industrial process contribute a lot to the high concentrations in urban Hangzhou, Suzhou and Shanghai. The contribution from regional elevated power plants cannot be neglected, especially to Dianshan Lake. Fugitive emissions of volatile pollution sources also have certain contribution to regional O3. These results indicate that the regional collaboration is of most importance to reduce ambient ozone pollution, particularly during high ozone episodes.

Investigation of Biogenic and Non-biogenic Methane Sources in Texas

NASA Astrophysics Data System (ADS)

Yang, S.; Talbot, R. W.; Liu, L.; Lan, X.

2016-12-01

Methane (CH4) is a potent greenhouse gas with its mixing ratio increasing in the global atmosphere. Texas is one of the significant areas where underestimation of CH4 emissions by the U.S. inventories are pronounced. This study focused on two areas of Texas: Houston, the energy capital of the world, and the Barnett Shale area which is one of the largest onshore natural gas fields in the United States. The investigation of background CH4 and the fingerprints of CH4 emissions are critical to understanding potential impacts of extensive nature gas operations in these two areas. One-year of stationary CH4 measurements were studied to deduce the regional background CH4 characteristics and to identify the principle CH4 sources in Houston. Key information concerning CH4 sources can be obtained through the stable carbon isotope δ13CH4 during two field campaigns using a state-of-the-art mobile laboratory. CH4 mixing ratio and δ13C in CH4 were sampled by two cavity ring-down spectrometers (CRDS), one of which is coupled to a custom air core 13C sampling device which can supply more than 600 measurements for each plume analysis. Here, we report results of the overall δ13CH4 values and CH4 emission signatures derived from thirty-three sources in the two studied areas, ranging from oil production and processing, waste managements and landfills, to livestock. δ13CH4 signatures of these sources vary from -76‰ to -23‰. Several repeated measurements were sampled to investigate the variability of source signatures. We investigated a case of unexpected massive CH4 leaking detected near the San Jacinto River Fleet site. At the regional scale, the comparison of background δ13CH4 signatures were conducted to obtain the difference of dominate CH4 sources in two study areas. At the local scale, the combination of tower and mobile lab measurements were used to estimate and characterize CH4 emissions in Houston. The results and findings can supply valuable references for the local emission inventory and atmospheric model inputs.

40 CFR 63.11502 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... begins with the initiation of steps as described in a written standard operating procedures (SOP) or... PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources...

Quantification of Gas Emissions from Refinieries, Gas Stations, Oil Wells and Agriculture using Optical Solar Occultation Flux and Tracer Correlation Methods

NASA Astrophysics Data System (ADS)

Mellqvist, J.; Samuelsson, J.; Marianne, E.; Brohede, S.; Andersson, P.; Johansson, J.; Isoz, O.; Tisopulos, L.; Polidori, A.; Pikelnaya, O.

2016-12-01

Industrial volatile organic compound (VOC) emissions may contribute significantly to ozone formation. In order to investigate how much small sources contribute to the VOC concentrations in the Los Angeles metropolitan area a comprehensive emission study has been carried out on behalf of the South Coast Air Quality Management District (SCAQMD). VOC emissions from major sources such as refineries, oil wells, petrol stations oil depots and oil platforms were measured during September and October 2015 using several unique optical methods, including the Solar Occultation Flux method (SOF) and tracer correlation technique based on extractive FTIR and DOAS combined with an open path multi reflection cell. In addition, measurements of ammonia emissions from farming in Chino were demonstrated. The measurements in this study were quality assured by carrying out a controlled source gas release study and side by side measurements with several other techniques. The results from the field campaign show that the emissions from the above mentioned sources are largely underestimated in inventories with potential impact on the air quality in the Los Angeles metropolitan area. The results show that oil and gas production is a very significant VOC emission source. In this presentation the techniques will be discussed together with the main results from the campaign including the quality assurance work.

75 FR 9647 - National Emission Standards for Hazardous Air Pollutants for Reciprocating Internal Combustion...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

...EPA is promulgating national emission standards for hazardous air pollutants for existing stationary compression ignition reciprocating internal combustion engines that either are located at area sources of hazardous air pollutant emissions or that have a site rating of less than or equal to 500 brake horsepower and are located at major sources of hazardous air pollutant emissions. In addition, EPA is promulgating national emission standards for hazardous air pollutants for existing non-emergency stationary compression ignition engines greater than 500 brake horsepower that are located at major sources of hazardous air pollutant emissions. Finally, EPA is revising the provisions related to startup, shutdown, and malfunction for the engines that were regulated previously by these national emission standards for hazardous air pollutants.

Effect of low emission sources on air quality in Cracow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nedoma, J.

1995-12-31

The paper presents calculation of power engineering low emission and results of stimulation of the effect of this emission on air quality in Cracow, Poland. It has been stated that the segment of low emission in central areas of the town makes up ca. 40% of the observed concentration of sulfur dioxide. Furthermore it has been stated that the capital investment must be concentrated in the central part of the town in order to reach noticeable improvement of air quality in Cracow. Neither the output of a separate power source nor the emission level and its individual harmful effect, butmore » the location of the source and especially packing density of the sources must decide the priority of upgrading actions.« less

Bisphenol A emission factors from industrial sources and elimination rates in a sewage treatment plant.

PubMed

Fuerhacker, M

2003-01-01

Bisphenol A (BPA) is widely used for the production of epoxy resins and polycarbonate plastics and is considered an endocrine disruptor. Special in vitro test systems and animal experiments showed a weak estrogenic activity. Aquatic wildlife especially could be endangered by waste water discharges. To manage possible risks arising from BPA emissions the major fluxes need to be investigated and the sources of the contamination of municipal treatment plants need to be determined. In this study, five major industrial point sources, two different household areas and the influent and effluent of the corresponding treatment plant (WWTP) were monitored simultaneously at a plant serving 120,000 population equivalents. A paper producing plant was the major BPA contributor to the influent load of the wastewater treatment plant. All the other emissions from point sources, including the two household areas, were considerably lower. The minimum elimination rate in the WTTP could be determined at 78% with an average of 89% of the total BPA-load. For a possible pollution-forecast, or for a comparison between different point sources, emission factors based on COD-emissions were calculated for industrial and household point sources at BPA/COD-ratios between 1.4 x 10(-8) - 125 x 10(-8) and 1.3 x 10(-6) - 6.3 x 10(-6), respectively.

Modeling Trip Duration for Mobile Source Emissions Forecasting

DOT National Transportation Integrated Search

2000-08-01

The distribution of the duration of trips in a metropolitan area is an important input to estimating area-wide running loss emissions, operating mode fractions and vehicle miles of travel (VMT) accumulated on local roads in the region. In the current...

Greenhouse gas emissions from Australian open-cut coal mines: contribution from spontaneous combustion and low-temperature oxidation.

PubMed

Day, Stuart J; Carras, John N; Fry, Robyn; Williams, David J

2010-07-01

Spontaneous combustion and low-temperature oxidation of waste coal and other carbonaceous material at open-cut coal mines are potentially significant sources of greenhouse gas emissions. However, the magnitude of these emissions is largely unknown. In this study, emissions from spontaneous combustion and low-temperature oxidation were estimated for six Australian open-cut coal mines with annual coal production ranging from 1.7 to more than 16 Mt. Greenhouse emissions from all other sources at these mines were also estimated and compared to those from spontaneous combustion and low-temperature oxidation. In all cases, fugitive emission of methane was the largest source of greenhouse gas; however, in some mines, spontaneous combustion accounted for almost a third of all emissions. For one mine, it was estimated that emissions from spontaneous combustion were around 250,000 t CO(2)-e per annum. The contribution from low-temperature oxidation was generally less than about 1% of the total for all six mines. Estimating areas of spoil affected by spontaneous combustion by ground-based surveys was prone to under-report the area. Airborne infrared imaging appears to be a more reliable method.

40 CFR 63.11567 - Who implements and enforces this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

...). 2. A high-efficiency air filter or fiber bed filter a. Inlet gas temperature b, andb. Pressure drop...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt...

DEVELOPMENT OF A MODEL FOR REAL TIME CO CONCENTRATIONS NEAR ROADWAYS

EPA Science Inventory

Although emission standards for mobile sources continue to be tightened, tailpipe emissions in urban areas continue to be a major source of human exposure to air toxics. Current human exposure models using simplified assumptions based on fixed air monitoring stations and region...

Observations of the young supernova remnant RX J1713.7–3946 with the Fermi Large Area Telescope

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2011-05-23

Here, we present observations of the young supernova remnant (SNR) RX J1713.7–3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0°.55 ± 0°.04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7–3946. The spectrum of the source can be described by a very hard power law with a photon index of Γ = 1.5 ± 0.1 that coincidesmore » in normalization with the steeper H.E.S.S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.« less

OBSERVATIONS OF THE YOUNG SUPERNOVA REMNANT RX J1713.7-3946 WITH THE FERMI LARGE AREA TELESCOPE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A. A.; Ackermann, M.; Ajello, M.

We present observations of the young supernova remnant (SNR) RX J1713.7-3946 with the Fermi Large Area Telescope (LAT). We clearly detect a source positionally coincident with the SNR. The source is extended with a best-fit extension of 0.{sup 0}55 {+-} 0.{sup 0}04 matching the size of the non-thermal X-ray and TeV gamma-ray emission from the remnant. The positional coincidence and the matching extended emission allow us to identify the LAT source with SNR RX J1713.7-3946. The spectrum of the source can be described by a very hard power law with a photon index of {Gamma} = 1.5 {+-} 0.1 thatmore » coincides in normalization with the steeper H.E.S.S.-detected gamma-ray spectrum at higher energies. The broadband gamma-ray emission is consistent with a leptonic origin as the dominant mechanism for the gamma-ray emission.« less

Measurements of Greenhouse Gases around the Sacramento Area: The Airborne Greenhouse Emissions Survey (AGES) Campaign

NASA Astrophysics Data System (ADS)

Karion, A.; Fischer, M. L.; Turnbull, J. C.; Sweeney, C.; Faloona, I. C.; Zagorac, N.; Guilderson, T. P.; Saripalli, S.; Sherwood, T.

2009-12-01

The state of California is leading the United States by enacting legislation (AB-32) to reduce greenhouse gas emissions to 1990 levels by 2020. The success of reduction efforts can be gauged with accurate emissions inventories and potentially verified with atmospheric measurements of greenhouse gases (GHGs) over time. Measurements of multiple GHGs and associated trace gas species in a specific region also provide information on emissions ratios for source apportionment. We conducted the Airborne Greenhouse Emissions Survey (AGES) campaign to determine emissions signature ratios for the sources that exist in the San Francisco Bay and Sacramento Valley areas. Specifically, we attempt to determine the emissions signatures of sources that influence ongoing measurements made at a tall-tower measurement site near Walnut Grove, CA. For two weeks in February and March of 2009, a Cessna 210 was flown throughout the Sacramento region, making continuous measurements of CO2, CH4, and CO while also sampling discrete flasks for a variety of additional tracers, including SF6, N2O, and 14C in CO2 (Δ14CO2). Flight paths were planned using wind predictions for each day to maximize sampling of sources whose emissions would also be sampled contemporaneously by the instrumentation at the Walnut Grove tower (WGC), part of the ongoing California Greenhouse Gas Emissions Measurement (CALGEM) project between NOAA/ESRL’s Carbon Cycle group and Lawrence Berkeley National Laboratory (LBNL). Flights were performed in two distinct patterns: 1) flying across a plume upwind and downwind of the Sacramento urban area, and 2) flying across the Sacramento-San Joaquin Delta from Richmond to Walnut Grove, a region consisting of natural wetlands as well as several power plants and refineries. Results show a variety of well-correlated mixing ratio signals downwind of Sacramento, documenting the urban signature emission ratios, while emissions ratios in the Delta region were more variable, likely due to the both natural and anthropogenic sources in that region. Periodic flask measurements of Δ14CO2 provide additional insight regarding the partitioning of CO2 emissions due to fossil fuel (deficient in 14C) from those of biospheric sources. A strong correlation between fossil-fuel CO2 and CO was measured downwind of Sacramento, suggesting that the continuous measurements of CO can be used to estimate a continuous profile of fossil-fuel CO2 enhancement in this region.

Contribution of Fugitive Emissions for PM10 Concentrations in an Industrial Area of Portugal

NASA Astrophysics Data System (ADS)

Marta Almeida, Susana; Viana Silva, Alexandra; Garcia, Silvia; Miranda, Ana Isabel

2013-04-01

Significant atmospheric dust arises from the mechanical disturbance of granular material exposed to the air. Dust generated from these open sources is termed "fugitive" because it is not discharged to the atmosphere in a confined flow stream. Common sources of fugitive dust include unpaved roads, agricultural tilling operations, aggregate storage piles, heavy construction and harbor operations. The objective of this work was to identify the likeliness and extend of the PM10 limit value exceedences due to fugitive emissions in a particularly zone where PM fugitive emissions are a core of environmental concerns - Mitrena, Portugal. Mitrena, is an industrial area that coexists with a high-density urban region (Setúbal) and areas with an important environmental concern (Sado Estuary and Arrábida which belongs to the protected area Natura 2000 Network). Due to the typology of industry sited in Mitrena (e.g. power plant, paper mill, cement, pesticides and fertilized productions), there are a large uncontrolled PM fugitive emissions, providing from heavy traffic and handling and storage of raw material on uncover stockyards in the harbor and industries. Dispersion modeling was performed with the software TAPM (The Air Pollution Model) and results were mapped over the study area, using GIS (Geographic Information Systems). Results showed that managing local particles concentrations can be a frustrating affair because the weight of fugitive sources is very high comparing with the local anthropogenic stationary sources. In order to ensure that the industry can continue to meet its commitments in protecting air quality, it is essential to warrant that the characteristics of releases from all fugitive sources are fully understood in order to target future investments in those areas where maximum benefit will be achieved.

PM2.5 Emission Elemental Composition from Diverse Combustion Sources in the Metropolitan Area of Mexico City

PubMed Central

Mugica, V.; Mugica, F.; Torres, M.; Figueroa, J.

2008-01-01

A field study was carried out from 2003 to 2004 with the aim to develop the PM2.5 emission source profiles from light-duty gasoline and heavy-duty diesel vehicles, as well as emission source profiles from waste incineration, wood burning, LP gas combustion, and meat broiling. Over 25 chemical species were quantified from the fine particles emitted by the different combustion sources investigated, including organic and elemental carbon, ions, and elements. The OC/TC ratio found in the different PM2.5 profiles was dissimilar as well as the sulfate, nitrate, ammonium, soil species, and trace element content. Consequently, these combustion emission profiles could be used in source reconciliation studies for fine particles. PMID:18379705

Assessing the impact of industrial source emissions on atmospheric carbonaceous aerosol concentrations using routine monitoring networks.

PubMed

Sheesley, Rebecca J; Schauer, James J; Orf, Marya L

2010-02-01

Industrial sources can have a significant but poorly defined impact on ambient particulate matter concentrations in select areas. Detailed emission profiles are often not available and are hard to develop because of the diversity of emissions across time and space at large industrial complexes. A yearlong study was conducted in an industrial area in Detroit, MI, which combined real-time particle mass (tapered element oscillating microbalance) and black carbon (aetholometer) measurements with molecular marker measurements of monthly average concentrations as well as daily concentrations of select high pollution days. The goal of the study was to use the real-time data to define days in which the particulate matter concentration in the atmosphere was largely impacted by local source emissions and to use daily speciation data to derive emission profiles for the industrial source. When combined with motor vehicle exhaust, wood smoke and road dust profiles, the industrial source profile was used to determine the contribution of the local industrial source to the total organic carbon (OC) concentrations using molecular marker-chemical mass balance modeling (MM-CMB). The MM-CMB analysis revealed that the industrial source had minimal impact on the monthly average carbonaceous aerosol concentration, but contributed approximately 2 microg m(-3), or a little over one-third of the total OC, on select high-impact days.

Characterization of Black Carbon Mixing State

DOE Data Explorer

Sedlacek, Arthur; S, Satheesh; Springston, Stephen

2013-11-06

This measurement characterizes the types of BC emissions that result in near­surface BC­ containing particles in a region that is dominated by biomass and open pit/stove cooking. Specifically, examine three primary BC emission sources: (i) urban setting (e.g., fossil fuel emissions); and (ii) biomass burning. Source (i) are captured at the Indian Institute of Science (IISc) in Bangalore. Biomass emissions (ii) contains a series of 1­2 day measurement excursions to the rural area surrounding Bangalore.

Anthropogenic Methane Emissions in California's San Joaquin Valley: Characterizing Large Point Source Emitters

NASA Astrophysics Data System (ADS)

Hopkins, F. M.; Duren, R. M.; Miller, C. E.; Aubrey, A. D.; Falk, M.; Holland, L.; Hook, S. J.; Hulley, G. C.; Johnson, W. R.; Kuai, L.; Kuwayama, T.; Lin, J. C.; Thorpe, A. K.; Worden, J. R.; Lauvaux, T.; Jeong, S.; Fischer, M. L.

2015-12-01

Methane is an important atmospheric pollutant that contributes to global warming and tropospheric ozone production. Methane mitigation could reduce near term climate change and improve air quality, but is hindered by a lack of knowledge of anthropogenic methane sources. Recent work has shown that methane emissions are not evenly distributed in space, or across emission sources, suggesting that a large fraction of anthropogenic methane comes from a few "super-emitters." We studied the distribution of super-emitters in California's southern San Joaquin Valley, where elevated levels of atmospheric CH4 have also been observed from space. Here, we define super-emitters as methane plumes that could be reliably detected (i.e., plume observed more than once in the same location) under varying wind conditions by airborne thermal infrared remote sensing. The detection limit for this technique was determined to be 4.5 kg CH4 h-1 by a controlled release experiment, corresponding to column methane enhancement at the point of emissions greater than 20% above local background levels. We surveyed a major oil production field, and an area with a high concentration of large dairies using a variety of airborne and ground-based measurements. Repeated airborne surveys (n=4) with the Hyperspectral Thermal Emission Spectrometer revealed 28 persistent methane plumes emanating from oil field infrastructure, including tanks, wells, and processing facilities. The likelihood that a given source type was a super-emitter varied from roughly 1/3 for processing facilities to 1/3000 for oil wells. 11 persistent plumes were detected in the dairy area, and all were associated with wet manure management. The majority (11/14) of manure lagoons in the study area were super-emitters. Comparing to a California methane emissions inventory for the surveyed areas, we estimate that super-emitters comprise a minimum of 9% of inventoried dairy emissions, and 13% of inventoried oil emissions in this region.

Impacts of interstate transport of pollutants on high ozone events over the Mid-Atlantic United States

NASA Astrophysics Data System (ADS)

Liao, Kuo-Jen; Hou, Xiangting; Baker, Debra Ratterman

2014-02-01

The impacts of interstate transport of anthropogenic nitrogen oxides (NOx) and volatile organic compound (VOC) emissions on peak ozone formation in four nonattainment areas (i.e., Baltimore, Philadelphia-Wilmington-Atlantic City, Pittsburgh-Beaver Valley and Washington, DC) in the Mid-Atlantic U.S. were quantified in this study. Regional air quality and sensitivities of ground-level ozone to emissions from four regions in the eastern U.S. were simulated for three summer months (June, July and August) in 2007 using the U.S. EPA's Community Multiscale Air Quality model with the decoupled direct method 3D. The emissions inventory used in this study was the 2007 Mid-Atlantic Regional Air Management Association Level 2 inventory, developed for State Implementation Plan screening modeling for the Ozone Transport Commission region. The modeling results show that responses of peak ozone levels at specific locations to emissions from EGU (i.e., electric generating unit) and non-EGU sources could be different. Therefore, emissions from EGU and non-EGU sources should be considered as two different control categories when developing regional air pollution mitigation strategies. Based on the emission inventories used in this study, reductions in anthropogenic NOx emissions (including those from EGU and non-EGU sources) from the Great Lake region as well as northeastern and southeastern U.S. would be effective for decreasing area-mean peak ozone concentrations during the summer of 2007 in the Mid-Atlantic ozone air quality nonattainment areas. The results also show that reductions in anthropogenic VOC emissions from the northeastern U.S. would also be effective for decreasing area-mean peak ozone concentrations over the Mid-Atlantic U.S. In some cases, reductions in anthropogenic NOx emissions from the Great Lake and northeastern U.S. could slightly increase area-mean peak ozone concentrations at some ozone monitors in the Pittsburgh-Beaver Valley and Washington, DC areas. However, the disbenefit of the slight increase in ozone concentrations attributed to the NOx emission controls was far outweighed by the overall ozone air quality benefits over the Mid-Atlantic region.

Analysis of land surface and synoptic conditions during dust storm events in the Middle East via a new high resolution inventory of mineral dust derived from SEVIRI.

NASA Astrophysics Data System (ADS)

Hennen, Mark

2017-04-01

This paper provides the most up-to-date dust climatology for the Middle East, presenting a new high resolution inventory of over 27,000 dust emission events observed over the Middle East in 2006 - 2013. The inventory was derived from the dust RGB product of the Spinning Enhanced Visual and InfraRed Imager (SEVIRI) on-board Meteosat's second generation satellite (MSG). Mineral dust emissions were derived from visual inspection of the SEVIRI scenes which have 4-5 km2 spatial and 15-minute temporal resolution. The location of every emission event was recorded in a database, along with time and trajectory of dust movement. This is an improvement on previous studies, which derive dust source areas from the daily observations of Aerosol Optical Depth whose maxima do not necessarily coincide with sources of emissions and produces more accurate information on the location of the key dust sources in the region. Results showed that dust sources are constrained to relatively small areas, with 21% of dust emission generated from just 0.9% of total surface area of the Middle East, mainly from eight source regions including the Tigris-Euphrates flood plains of Iraq and Syria, Western and Northern Saudi Arabia and the Sistan Basin in Eastern Iran. The Tigris-Euphrates flood plain was the most active dust region, producing 41% of all dust events with a peak activity in 2009. The southern areas of the Arabian Peninsula recorded very few dust emission observations, in contrast to many previous studies which do not use such high temporal resolution data. The activation and frequency of dust emissions are characterised by strong seasonality developing in response to specific synoptic conditions. To characterise synoptic conditions conducive to the development of dust storms, dust days' emission thresholds, based on number of dust emission events per day / per region and specific to each of the eight main dust emitting regions, were determined. ERA Interim reanalysis data were used to characterise synoptic conditions on the identified dust days. With vegetation cover dictating the ability for surface areas to deflate, Normalised Difference Vegetation Index (NDVI) data was acquired from the Moderate Resolution Imaging Spectrodiometer (MODIS) (MOD13A2) 1km database and correlated with dust emission frequency data in the region of greatest dust activity, the Tigris and Euphrates flood plain in Iraq and Syria.

Greenhouse Gas Source Detection and Attribution in the San Francisco Bay Area of California Using a Mobile Measurement Platform

NASA Astrophysics Data System (ADS)

Martien, P. T.; Guha, A.; Newman, S.; Young, A.; Bower, J.; Perkins, I.; Randall, S.; Stevenson, E.; Hilken, H.

2017-12-01

The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate goals. Recently, the Air District's governing board adopted a 2017 Clean Air Plan advancing the agency's vision and including actions to put the region on a path to achieving the 2050 goal while also reducing air pollution and related health impacts. The Plan includes GHG rule-making efforts, policy initiatives, local government partnerships, outreach, grants and incentives, encompassing over 250 specific implementation actions across all economic sectors to effect ambitious emission reductions in the region. To support the 2017 Plan, the Air District has built a mobile measurement platform (GHG research van) to perform targeted CH4 emissions hotspot detection and source attribution. Instruments in the van measure CH4, CO2 and N2O in ambient plumes. Coincident measurements of source tracers like isotopic methane (13C - CH4), CO and ethane (C2H6) provide the capability to distinguish between biogenic, combustion-based and fossil-based fugitive methane sources. We report observations of CH4 plumes from source-specific measurements in and around facilities including a wastewater treatment plant, a composting operation, a waste-to-energy anaerobic digestion plant and a few refineries. We performed leak surveys inside several electric utility-operated facilities including a power plant and an underground natural gas storage facility. We sampled exhaust from a roadway tunnel and computed fleet-averaged automobile-related CH4 and N2O emission factors. We used tracer-to-tracer emission ratios to create chemical signatures of emissions from each sampled source category. We compare measurement-based ratios with those used to derive the regional GHG inventory. Data from these and other sources will lead to an improved understanding of GHG emissions from well- and lesser-known CH4 sources in the region, key to resolving the differences between top-down estimates (Fairley and Fischer, 2015; Jeong et al., 2016) and the regional bottom-up inventory.

Trends of multiple air pollutants emissions from residential coal combustion in Beijing and its implication on improving air quality for control measures

NASA Astrophysics Data System (ADS)

Xue, Yifeng; Zhou, Zhen; Nie, Teng; Wang, Kun; Nie, Lei; Pan, Tao; Wu, Xiaoqing; Tian, Hezhong; Zhong, Lianhong; Li, Jing; Liu, Huanjia; Liu, Shuhan; Shao, Panyang

2016-10-01

Residential coal combustion is considered to be an important source of air pollution in Beijing. However, knowledge regarding the emission characteristics of residential coal combustion and the related impacts on the air quality is very limited. In this study, we have developed an emission inventory for multiple hazardous air pollutants (HAPs) associated with residential coal combustion in Beijing for the period of 2000-2012. Furthermore, a widely used regional air quality model, the Community Multi-Scale Air Quality model (CMAQ), is applied to analyze the impact of residential coal combustion on the air quality in Beijing in 2012. The results show that the emissions of primary air pollutants from residential coal combustion have basically remained the same levels during the past decade, however, along with the strict emission control imposed on major industrial sources, the contribution of residential coal combustion emissions to the overall emissions from anthropogenic sources have increased obviously. In particular, the contributions of residential coal combustion to the total air pollutants concentrations of PM10, SO2, NOX, and CO represent approximately 11.6%, 27.5%, 2.8% and 7.3%, respectively, during the winter heating season. In terms of impact on the spatial variation patterns, the distributions of the pollutants concentrations are similar to the distribution of the associated primary HAPs emissions, which are highly concentrated in the rural-urban fringe zones and rural suburb areas. In addition, emissions of primary pollutants from residential coal combustion are forecasted by using a scenario analysis. Generally, comprehensive measures must be taken to control residential coal combustion in Beijing. The best way to reduce the associated emissions from residential coal combustion is to use economic incentive means to promote the conversion to clean energy sources for residential heating and cooking. In areas with reliable energy supplies, the coal used for residential heating can be replaced with gas-burning wall-heaters, ground-source heat pumps, solar energy and electricity. In areas with inadequate clean energy sources, low-sulfur coal should be used instead of the traditional raw coal with high sulfur and ash content, thereby slightly reducing the emissions of PM, SO2, CO and other toxic pollutants.

Is forest management a significant source of monoterpenes into the boreal atmosphere?

NASA Astrophysics Data System (ADS)

Haapanala, S.; Hakola, H.; Hellén, H.; Vestenius, M.; Levula, J.; Rinne, J.

2011-08-01

Volatile organic compounds (VOCs) including terpenoids are emitted into the atmosphere from various natural sources. Damaging the plant tissue is known to strongly increase their monoterpene release. We measured the terpenoid emissions caused by timber felling, i.e. those from stumps and logging residue. The emissions from stumps were studied using enclosures and those from the whole felling area using an ecosystem scale micrometeorological method, disjunct eddy accumulation (DEA). The compounds analyzed were isoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpenes were measured from both the stumps and from the whole felling area. The emission rate fell down rapidly within few months after the logging. In addition to fresh logging residue, the results suggest also other strong monoterpene sources to be present at the felling area. Those could include pre-existing litter, increased microbial activity and remaining undergrowth. To evaluate the possible importance of monoterpenes emitted from cut Scots pine forests in Finland annually, we conducted a rough upscaling. The resulting monoterpene release was about 15 kilotonnes per year which is more than 10 % of the monoterpene release from intact forests in Finland.

Improved quantification of CO2 emission at Campi Flegrei by combined Lagrangian Stochastic and Eulerian dispersion modelling

NASA Astrophysics Data System (ADS)

Pedone, Maria; Granieri, Domenico; Moretti, Roberto; Fedele, Alessandro; Troise, Claudia; Somma, Renato; De Natale, Giuseppe

2017-12-01

This study investigates fumarolic CO2 emissions at Campi Flegrei (Southern Italy) and their dispersion in the lowest atmospheric boundary layer. We innovatively utilize a Lagrangian Stochastic dispersion model (WindTrax) combined with an Eulerian model (DISGAS) to diagnose the dispersion of diluted gas plumes over large and complex topographic domains. New measurements of CO2 concentrations acquired in February and October 2014 in the area of Pisciarelli and Solfatara, the two major fumarolic fields of Campi Flegrei caldera, and simultaneous measurements of meteorological parameters are used to: 1) test the ability of WindTrax to calculate the fumarolic CO2 flux from the investigated sources, and 2) perform predictive numerical simulations to resolve the mutual interference between the CO2 emissions of the two adjacent areas. This novel approach allows us to a) better quantify the CO2 emission of the fumarolic source, b) discriminate ;true; CO2 contributions for each source, and c) understand the potential impact of the composite CO2 plume (Pisciarelli ;plus; Solfatara) on the highly populated areas inside the Campi Flegrei caldera.

Characterizing the detectability of emission signals from a North Korean nuclear detonation

DOE PAGES

Werth, David; Buckley, Robert

2017-02-01

Here, the detectability of emission sources, defined by a low-level of mixing with other sources, was estimated for various locations surrounding the Sea of Japan, including a site within North Korea. A high-resolution meteorological model coupled to a dispersion model was used to simulate plume dynamics for four periods, and two metrics of airborne plume mixing were calculated for each source. While emissions from several known sources in this area tended to blend with others while dispersing downwind, the North Korean plume often remained relatively distinct, thereby making it potentially easier to unambiguously ‘backtrack’ it to its source.

Summary of Energy Assessment Requirements under the Area Source Boiler Rule

EPA Pesticide Factsheets

This document provides an overview of the energy assessment requirements for the national emission standards for hazardous air pollutants (NESHAP) for area sources: industrial, commercial and Institutional boilers, 40 CFR Part 63, Subpart JJJJJJ.

Temperature and air velocity effects on ethanol emission from corn silage

USDA-ARS?s Scientific Manuscript database

Volatile organic compounds (VOCs) from agricultural sources are believed to be an important contributor to tropospheric ozone in some areas. Recent research suggests that silage is a major source of these VOCs, but only limited data exist on VOC emission from silage. Ethanol is normally the most abu...

Analysis of heavy metal sources in storm water from urban areas

NASA Astrophysics Data System (ADS)

Scherer, U.; Fuchs, S.

2009-04-01

The input of heavy metals into surface waters is a serious impairment of the aquatic environment. The emissions of heavy metals via point and diffuse pathways into the German river basins were thus quantified for the period of 1985 through 2005. The total emission into the German river systems decreased for each metal during the observed period. This reduction is mainly caused by the decline of emissions via point sources. The measures taken by industry and implemented within the scope of a stringently water legislation have decisively contributed to an improvement of environmental conditions. Today's emissions of heavy metals into river basins of Germany are dominated by the input via diffuse pathways. One of the most important diffuse input is the storm water discharged from paved urban areas into the surface waters via storm sewers and combined sewer overflows especially for the metals copper, zinc and lead. The objective of this project was to identify the sources of these three heavy metals washed of from paved urban areas. The use of copper, zinc and lead on the outsides of buildings results in emissions to water and soil via rainwater due to weathering and runoff of soluble and insoluble metallic compounds. Copper and zinc are traditionally used materials in the building sector especially for roofs, gutters and facades. Lead, in contrast, plays only a subordinate role due to its more limited outdoor use. The corrosion rates vary widely. Climatic factors (temperature, humidity etc.), above all the presence of corrosive gases (sulphur dioxide, nitrogen oxide, ozone etc.) influence the corrosion processes. Estimates of industrial associations were referred to in order to determine the corrosion relevant metal surfaces. Heavy metal emissions caused by traffic are complex and depend on many parameters which vary by locality, time and substance. In principle, substances can be emitted by vehicles, the road surface and by maintenance. Emissions of copper, lead and zinc are mainly caused by wear and tear of tyres and brake pads. The reference figures of the environmental emissions are usually the kilometres driven per vehicle. The emissions can then be calculated based on the road performance. Furthermore atmospheric deposition on paved urban areas was considered. The heavy metal emission from each individual source and the portion discharged into surface waters via storm sewers and combined sewer overflows was quantified. The emission sum of all sources was validated using emission data of storm sewers based on measured heavy metal concentrations and the discharge volume showing a good agreement.

Nitrogen emissions, deposition, and monitoring in the Western United States

USGS Publications Warehouse

Fenn, M.E.; Haeuber, R.; Tonnesen, G.S.; Baron, Jill S.; Grossman-Clarke, S.; Hope, D.; Jaffe, D.A.; Copeland, S.; Geiser, L.; Rueth, H.M.; Sickman, J.O.

2003-01-01

Nitrogen (N) deposition in the western United States ranges from 1 to 4 kilograms (kg) per hectare (ha) per year over much of the region to as high as 30 to 90 kg per ha per year downwind of major urban and agricultural areas. Primary N emissions sources are transportation, agriculture, and industry. Emissions of N as ammonia are about 50% as great as emissions of N as nitrogen oxides. An unknown amount of N deposition to the West Coast originates from Asia. Nitrogen deposition has increased in the West because of rapid increases in urbanization, population, distance driven, and large concentrated animal feeding operations. Studies of ecological effects suggest that emissions reductions are needed to protect sensitive ecosystem components. Deposition rates are unknown for most areas in the West, although reasonable estimates are available for sites in California, the Colorado Front Range, and central Arizona. National monitoring networks provide long-term wet deposition data and, more recently, estimated dry deposition data at remote sites. However, there is little information for many areas near emissions sources.

Developing particle emission inventories using remote sensing (PEIRS).

PubMed

Tang, Chia-Hsi; Coull, Brent A; Schwartz, Joel; Lyapustin, Alexei I; Di, Qian; Koutrakis, Petros

2017-01-01

Information regarding the magnitude and distribution of PM 2.5 emissions is crucial in establishing effective PM regulations and assessing the associated risk to human health and the ecosystem. At present, emission data is obtained from measured or estimated emission factors of various source types. Collecting such information for every known source is costly and time-consuming. For this reason, emission inventories are reported periodically and unknown or smaller sources are often omitted or aggregated at large spatial scale. To address these limitations, we have developed and evaluated a novel method that uses remote sensing data to construct spatially resolved emission inventories for PM 2.5 . This approach enables us to account for all sources within a fixed area, which renders source classification unnecessary. We applied this method to predict emissions in the northeastern United States during the period 2002-2013 using high-resolution 1 km × 1 km aerosol optical depth (AOD). Emission estimates moderately agreed with the EPA National Emission Inventory (R 2 = 0.66-0.71, CV = 17.7-20%). Predicted emissions are found to correlate with land use parameters, suggesting that our method can capture emissions from land-use-related sources. In addition, we distinguished small-scale intra-urban variation in emissions reflecting distribution of metropolitan sources. In essence, this study demonstrates the great potential of remote sensing data to predict particle source emissions cost-effectively. We present a novel method, particle emission inventories using remote sensing (PEIRS), using remote sensing data to construct spatially resolved PM 2.5 emission inventories. Both primary emissions and secondary formations are captured and predicted at a high spatial resolution of 1 km × 1 km. Using PEIRS, large and comprehensive data sets can be generated cost-effectively and can inform development of air quality regulations.

Characterization of alluvial dust sources and their temporal development - a multi-sensor approach for the Aïr Massif, Niger

NASA Astrophysics Data System (ADS)

Feuerstein, Stefanie; Schepanski, Kerstin

2017-04-01

One of the world's largest sources of atmospheric dust is the Sahara. It is said that 55% of the total global dust emission can be linked to the desert in northern Africa. Thus, understanding the Saharan dust sources is of great importance to estimate the total global dust load and its variability. Especially one type of dust sources has gained attention in dust research in recent years: The emission of dust from sediments formed by hydrologic processes, so called alluvial dust sources. These sediments were either formed in the past under the influences of a more humid paleoclimate or are deposited recently, e.g. during strong precipitation events when surficial runoff leads to the activation of wadi systems or to the occurrence of flash floods. Especially the latter phenomenon is able to deliver a huge amount of potentially erodible sediments. The research presented here focuses on the characterization of these alluvial dust sources with special attention on their temporal variability in relation to wet and dry phases. A study area covering the Aïr Massif in Niger is analysed over a four years time span from January 2013 to December 2016. The whole cycle from sediment formation to dust emission is illustrated by using data of various satellite sensors that are able to capture the processes taking place at the land surface as well as in the atmosphere: (1) The rainfall distribution for the study area is shown by time series of the TRMM precipitation estimates. A catchment analysis of the area helps to estimate the amount of surficial runoff and to detect areas of potential sediment accumulation. (2) Changes in the sediment structure of the land surface are analysed using atmospherically corrected time series of NASA's Landsat-8 OLI satellite. A land cover classification shows the distribution of alluvial sediments over the area; fresh layers of alluvial deposits are detected. Furthermore, the evolution of the vegetation cover, which inhibits dust emission, is analysed by calculating NDVI time series from the Landsat data. (3) The MSG Dust Product is used to determine the frequency of dust emission from the investigation area. Furthermore, the product allows the precise localization of the sources. Therefore the alluvial sediments can directly be connected to dust emission. By combining the findings of these different satellite sensors, a profound analysis of alluvial dust sources on different levels is possible. The connection between the amount of precipitation and the supply of potentially erodible sediments is shown, which leads to a better understanding of the temporal evolution and importance of this source type.

[Estimation inventory of polycyclic aromatic hydrocarbons (PAHs) from anthropogenic sources and its impacts within the Yanghe Watershed, an important water-source site of Beijing, China].

PubMed

Gao, Jia-Jia; Luo, Wei; Xi, Xiao-Xia

2014-12-01

The Yanghe Watershed, situated at the upwind of Beijing, is an important water-source site and ecologic protection barrier for Beijing and Zhangjiakou cities. The Yanghe Watershed is also a farming-pastoral transitional area and an ecologically vulnerable and sensitive region, as well as the place applying for Winter Olympic Game in 2022. Establishment of atmospheric emissions inventory of polycyclic aromatic hydrocarbons (PAHs) and identification of its sources within the Yanghe Watershed and its possible transportation paths to Beijing can help us get a better understanding of regional environmental pollution (especially air environmental pollution) in Beijing-Zhangjiakou area. In the present study, PAHs emission from different counties and cities within the Yanghe Watershed in 2012 was calculated based on the statistical data of local industries, agriculture and resident living while PAHs emission factors were estimated. According to the cluster analysis for air transport trajectories, main categories of air masses were obtained. Results indicated that total emission of PAHs in 2012 was 4.4 x 10(2) t. Coal combustion and crop-straw burning were the most important emission sources of PAHs, accounting for 76% and 16% of total emission of PAHs, respectively. Xuanhua county had the greatest emission of PAHs (49 t), followed by Xinghe (36 t), Tianzhen (32 t), Huailai (24 t) and Wanquan (15 t). In emission of 16 isomers of PAHs, the emission of high molecular weight isomers containing 4-6 rings was approximate to that of low molecular weight isomers containing 2-3 rings, accounting for approximately 50% of total emission of PAHs. Emission of PAHs had positive correlations with gross industrial production (GIP) (r = 0.96, P < 0.05) and resident income (RI) (r = 0.94, P < 0.05) and population density (PD) (r = 0.92, P < 0.05), but negatively correlated with land area (LA) (r = - 0.9, P < 0.05) and no significant correlationship with gross output value of agriculture (GOA) (r = 0.026, P > 0.01). The high emission of PAHs within the Yanghe Watershed was associated with local energy structure and residents' consumption level. Combined the back trajectory analysis with PAHs emission, high amount of PAHs could be transported to Beijing by northwest airflow, suggesting its potential ecological risk and human health effect in Beijing.

Estimation of Biogenic VOC Emissions From Ecosystems in the Czech Republic

NASA Astrophysics Data System (ADS)

Zemankova, K.; Brechler, J.

2008-12-01

Volatile organic compounds (VOC) are one of the crucial elements in photochemical reactions in the atmosphere which lead to tropospheric ozone formation. While modelling concentration of low-level ozone proper information about VOC sources and sinks is necessary. VOC are emitted into the atmosphere both from anthropogenic and natural sources. It has been shown in previous studies (e.g. Simpson et al, 1995) that contribution of volatile organic compounds emitted from biogenic sources to total amount of VOC in the atmosphere can be significant. Our work focuses on estimation of VOC emissions from natural ecosystems, most importantly from forests, and its application in photochemical modelling. Preliminary results have shown that inclusion of biogenic emissions in model input data leads to improvement of resulting ozone concentration which encouraged us to work on detailed biogenic VOC emission estimation. Using grid of 1x1km CORINE Land Cover over the area of the Czech Republic, emissions from deciduous, coniferous and mixed forests were estimated aplying the algorithm of Guenther et al., 1995. According to data from Forest Management Institute each cell of model grid has been assigned a proportional composition of each of thirteen tree species which are the the main forest constituents in the Czech Republic. Aggregating data of tree species composition with land cover category emission factor of particular chemical compound (isoprene, monoterpenes) has been obtained for each cell. Annual emissions of VOC on hourly basis have been calculated for domain of the Czech Republic. Biogenic emissions of isoprene and monoterpenes were compared with the emission inventory of anthropogenic sources. The inventory is provided by Czech Hydrometeorological Institute and covers emissions from major stationary sources, area sources (including domestic heating) and mobile sources. Our results show that natural emissions are approximately half the amount of organic compounds emitted from anthropogenic sources. References: - Simpson D., Guenther A., Hewit C.N. and Steinbrecher R., 1995. Biogenic emissions in Europe. 1. estimates and uncertainties. J. Geophys. Res. 100(D11), 22875-22890. - Guenther A., Hewitt N., Erickson D., Fall R., Geron Ch., Graedel T., Harley P., Klinger L., Lerdau M., McKay W. A., Pierce T., Scholes B., Steinbrecher R., Tallamraju R., Taylor J., Zimmerman P., 1995. Global model of natural organic compound emissions. J. Geophys. Res. 100, 8873-8892.

Mobile Methane Monitoring Surveys of the Pinedale Anticline Development in the Upper Green River Basin of Wyoming

NASA Astrophysics Data System (ADS)

Field, R. A.; Soltis, J.; Murphy, S. M.; Montague, D. C.

2013-12-01

Methane emissions from the oil and gas sector have become part of a wider debate of the magnitude of climate change impacts from different fossil fuels. This debate is contentious, as a wide range of estimates of development area leakage rates have been postulated. Here we present the results of mobile monitoring performed in the Pinedale Anticline, WY (PAPA) development. A 4-hour circuit upwind, downwind and within the development was designed to determine methane distributions relative to background concentrations. The circuit was repeated thirty-two times to assess the influence of meteorology and emission sources upon measured values. Figure 1 is a composite of methane data for the project. This pilot project enabled identification of areas and emission sources for subsequent plume quantification studies planned for 2014. Here we present the finding of the circuits through mapping and site comparisons. Along with the methane measurements, mobile ozone and oxides of nitrogen observations were also performed, thereby facilitating a better understanding of the phenomenon of wintertime ground level ozone. Building upon surveys from 2012, we also carried out canister measurements of VOC at selected sites to demonstrate the importance of relating methane and selected VOC concentrations when identifying variations in the contributions of emission sources to ambient measurements. While methane and C2 to C5 alkanes elevations are widespread and highly correlated, those of higher molecular weight VOC, in particular benzene, toluene and xylene isomers, show the importance of emission sources other than wet gas leakage. We discuss the utility of 3D visualization of methane data for illustrating the distribution of leakage relative to emission sources. The influence of emission sources and meteorology upon the data is explored through a comparative analysis of the circuit data. This assessment sets the foundation for planned plume quantification. Finally we compare the mobile data with 1-minute data from the Wyoming DEQ site at Boulder, WY, to determine how well the site represents conditions in the surrounding area. Effective policy decisions require better coupling of air quality measurements and emission inventories. We outline an approach that links regulatory network site data with mobile monitoring and plume quantification that should reduce uncertainty for determining the magnitude of methane emissions from oil and gas sources. Pinedale Anticline methane concentrations for mobile monitoring circuits 2/12/2013 to 3/8/2013

Satellite-derived methane hotspot emission estimates using a fast data-driven method

NASA Astrophysics Data System (ADS)

Buchwitz, Michael; Schneising, Oliver; Reuter, Maximilian; Heymann, Jens; Krautwurst, Sven; Bovensmann, Heinrich; Burrows, John P.; Boesch, Hartmut; Parker, Robert J.; Somkuti, Peter; Detmers, Rob G.; Hasekamp, Otto P.; Aben, Ilse; Butz, André; Frankenberg, Christian; Turner, Alexander J.

2017-05-01

Methane is an important atmospheric greenhouse gas and an adequate understanding of its emission sources is needed for climate change assessments, predictions, and the development and verification of emission mitigation strategies. Satellite retrievals of near-surface-sensitive column-averaged dry-air mole fractions of atmospheric methane, i.e. XCH4, can be used to quantify methane emissions. Maps of time-averaged satellite-derived XCH4 show regionally elevated methane over several methane source regions. In order to obtain methane emissions of these source regions we use a simple and fast data-driven method to estimate annual methane emissions and corresponding 1σ uncertainties directly from maps of annually averaged satellite XCH4. From theoretical considerations we expect that our method tends to underestimate emissions. When applying our method to high-resolution atmospheric methane simulations, we typically find agreement within the uncertainty range of our method (often 100 %) but also find that our method tends to underestimate emissions by typically about 40 %. To what extent these findings are model dependent needs to be assessed. We apply our method to an ensemble of satellite XCH4 data products consisting of two products from SCIAMACHY/ENVISAT and two products from TANSO-FTS/GOSAT covering the time period 2003-2014. We obtain annual emissions of four source areas: Four Corners in the south-western USA, the southern part of Central Valley, California, Azerbaijan, and Turkmenistan. We find that our estimated emissions are in good agreement with independently derived estimates for Four Corners and Azerbaijan. For the Central Valley and Turkmenistan our estimated annual emissions are higher compared to the EDGAR v4.2 anthropogenic emission inventory. For Turkmenistan we find on average about 50 % higher emissions with our annual emission uncertainty estimates overlapping with the EDGAR emissions. For the region around Bakersfield in the Central Valley we find a factor of 5-8 higher emissions compared to EDGAR, albeit with large uncertainty. Major methane emission sources in this region are oil/gas and livestock. Our findings corroborate recently published studies based on aircraft and satellite measurements and new bottom-up estimates reporting significantly underestimated methane emissions of oil/gas and/or livestock in this area in EDGAR.

Characterizing CO and NOy Sources and Relative Ambient Ratios in the Baltimore Area Using Ambient Measurements and Source Attribution Modeling

NASA Astrophysics Data System (ADS)

Simon, Heather; Valin, Luke C.; Baker, Kirk R.; Henderson, Barron H.; Crawford, James H.; Pusede, Sally E.; Kelly, James T.; Foley, Kristen M.; Chris Owen, R.; Cohen, Ronald C.; Timin, Brian; Weinheimer, Andrew J.; Possiel, Norm; Misenis, Chris; Diskin, Glenn S.; Fried, Alan

2018-03-01

Modeled source attribution information from the Community Multiscale Air Quality model was coupled with ambient data from the 2011 Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality Baltimore field study. We assess source contributions and evaluate the utility of using aircraft measured CO and NOy relationships to constrain emission inventories. We derive ambient and modeled ΔCO:ΔNOy ratios that have previously been interpreted to represent CO:NOy ratios in emissions from local sources. Modeled and measured ΔCO:ΔNOy are similar; however, measured ΔCO:ΔNOy has much more daily variability than modeled values. Sector-based tagging shows that regional transport, on-road gasoline vehicles, and nonroad equipment are the major contributors to modeled CO mixing ratios in the Baltimore area. In addition to those sources, on-road diesel vehicles, soil emissions, and power plants also contribute substantially to modeled NOy in the area. The sector mix is important because emitted CO:NOx ratios vary by several orders of magnitude among the emission sources. The model-predicted gasoline/diesel split remains constant across all measurement locations in this study. Comparison of ΔCO:ΔNOy to emitted CO:NOy is challenged by ambient and modeled evidence that free tropospheric entrainment, and atmospheric processing elevates ambient ΔCO:ΔNOy above emitted ratios. Specifically, modeled ΔCO:ΔNOy from tagged mobile source emissions is enhanced 5-50% above the emitted ratios at times and locations of aircraft measurements. We also find a correlation between ambient formaldehyde concentrations and measured ΔCO:ΔNOy suggesting that secondary CO formation plays a role in these elevated ratios. This analysis suggests that ambient urban daytime ΔCO:ΔNOy values are not reflective of emitted ratios from individual sources.

Characterizing and locating air pollution sources in a complex industrial district using optical remote sensing technology and multivariate statistical modeling.

PubMed

Chang, Pao-Erh Paul; Yang, Jen-Chih Rena; Den, Walter; Wu, Chang-Fu

2014-09-01

Emissions of volatile organic compounds (VOCs) are most frequent environmental nuisance complaints in urban areas, especially where industrial districts are nearby. Unfortunately, identifying the responsible emission sources of VOCs is essentially a difficult task. In this study, we proposed a dynamic approach to gradually confine the location of potential VOC emission sources in an industrial complex, by combining multi-path open-path Fourier transform infrared spectrometry (OP-FTIR) measurement and the statistical method of principal component analysis (PCA). Close-cell FTIR was further used to verify the VOC emission source by measuring emitted VOCs from selected exhaust stacks at factories in the confined areas. Multiple open-path monitoring lines were deployed during a 3-month monitoring campaign in a complex industrial district. The emission patterns were identified and locations of emissions were confined by the wind data collected simultaneously. N,N-Dimethyl formamide (DMF), 2-butanone, toluene, and ethyl acetate with mean concentrations of 80.0 ± 1.8, 34.5 ± 0.8, 103.7 ± 2.8, and 26.6 ± 0.7 ppbv, respectively, were identified as the major VOC mixture at all times of the day around the receptor site. As the toxic air pollutant, the concentrations of DMF in air samples were found exceeding the ambient standard despite the path-average effect of OP-FTIR upon concentration levels. The PCA data identified three major emission sources, including PU coating, chemical packaging, and lithographic printing industries. Applying instrumental measurement and statistical modeling, this study has established a systematic approach for locating emission sources. Statistical modeling (PCA) plays an important role in reducing dimensionality of a large measured dataset and identifying underlying emission sources. Instrumental measurement, however, helps verify the outcomes of the statistical modeling. The field study has demonstrated the feasibility of using multi-path OP-FTIR measurement. The wind data incorporating with the statistical modeling (PCA) may successfully identify the major emission source in a complex industrial district.

A regional high-resolution emission inventory of primary air pollutants in 2012 for Beijing and the surrounding five provinces of North China

NASA Astrophysics Data System (ADS)

Liu, Huanjia; Wu, Bobo; Liu, Shuhan; Shao, Panyang; Liu, Xiangyang; Zhu, Chuanyong; Wang, Yong; Wu, Yiming; Xue, Yifeng; Gao, Jiajia; Hao, Yan; Tian, Hezhong

2018-05-01

A high resolution regional emission inventory of typical primary air pollutants (PAPs) for the year 2012 in Beijing and the surrounding five provinces (BSFP) of North China is developed. It is compiled with the combination of bottom-up and top-down methods, based on city-level collected activity data and the latest updated specific emission factors for different sources. The considered sources are classified into 12 major categories and totally 36 subcategories with respect to their multi-dimensional characteristics, such as economic sector, combustion facility or industrial process, installed air pollution control devices, etc. Power plant sector is the dominant contributor of NOX emissions with an average contribution of 34.1%, while VOCs emissions are largely emitted from industrial process sources (33.9%). Whereas, other stationary combustion sources represent major sources of primary PM2.5, PM10 and BC emissions, accounting for 22.7%, 30.0% and 33.9% of the total emissions, respectively. Hebei province contributes over 34% of the regional total CO emissions because of huge volume of iron and steel production. By comparison, Shandong province ranks as the biggest contributor for NOX, PM10, PM2.5, SO2, VOCs and OC. Further, the BSFP regional total emissions are spatially distributed into grid cells with a high resolution of 9 km × 9 km using GIS tools and surrogate indexes, such regional population, gross domestic product (GDP) and the types of arable soils. The highest emission intensities are mainly located in Beijing-Tianjin-Tangshan area, Jinan-Laiwu-Zibo area and several other cities such as Shijiazhuang, Handan, and Zhengzhou. Furthermore, in order to establish a simple method to estimate and forecast PAPs emissions with macroscopic provincial-level statistical parameters in China, multi-parameter regression equations are firstly developed to estimate emissions outside the BSFP region with routine statistics (e.g. population, total final coal consumption, area of cultivated land and possession of civil vehicles) using the software 1stOpt. We find the estimated PAPs emissions of 31 provinces show close correlation with the well-recognized MEIC inventory. This high resolution multi-pollutants inventory provides necessary input data for regional air quality models that could help to identify and appoint the major influence sources, better understand the complex regional air pollution formation mechanism, and benefit for developing the corresponding joint prevention and control policies of regional complex air pollution in North China.

Improvement of a Global High-Resolution Ammonia Emission Inventory for Combustion and Industrial Sources with New Data from the Residential and Transportation Sectors.

PubMed

Meng, Wenjun; Zhong, Qirui; Yun, Xiao; Zhu, Xi; Huang, Tianbo; Shen, Huizhong; Chen, Yilin; Chen, Han; Zhou, Feng; Liu, Junfeng; Wang, Xinming; Zeng, Eddy Y; Tao, Shu

2017-03-07

There is increasing evidence indicating the critical role of ammonia (NH 3 ) in the formation of secondary aerosols. Therefore, high quality NH 3 emission inventory is important for modeling particulate matter in the atmosphere. Unfortunately, without directly measured emission factors (EFs) in developing countries, using data from developed countries could result in an underestimation of these emissions. A series of newly reported EFs for China provide an opportunity to update the NH 3 emission inventory. In addition, a recently released fuel consumption data product has allowed for a multisource, high-resolution inventory to be assembled. In this study, an improved global NH 3 emission inventory for combustion and industrial sources with high sectorial (70 sources), spatial (0.1° × 0.1°), and temporal (monthly) resolutions was compiled for the years 1960 to 2013. The estimated emissions from transportation (1.59 Tg) sectors in 2010 was 2.2 times higher than those of previous reports. The spatial variation of the emissions was associated with population, gross domestic production, and temperature. Unlike other major air pollutants, NH 3 emissions continue to increase, even in developed countries, which is likely caused by an increased use of biomass fuel in the residential sector. The emissions density of NH 3 in urban areas is an order of magnitude higher than in rural areas.

Inference of emission rates from multiple sources using Bayesian probability theory.

PubMed

Yee, Eugene; Flesch, Thomas K

2010-03-01

The determination of atmospheric emission rates from multiple sources using inversion (regularized least-squares or best-fit technique) is known to be very susceptible to measurement and model errors in the problem, rendering the solution unusable. In this paper, a new perspective is offered for this problem: namely, it is argued that the problem should be addressed as one of inference rather than inversion. Towards this objective, Bayesian probability theory is used to estimate the emission rates from multiple sources. The posterior probability distribution for the emission rates is derived, accounting fully for the measurement errors in the concentration data and the model errors in the dispersion model used to interpret the data. The Bayesian inferential methodology for emission rate recovery is validated against real dispersion data, obtained from a field experiment involving various source-sensor geometries (scenarios) consisting of four synthetic area sources and eight concentration sensors. The recovery of discrete emission rates from three different scenarios obtained using Bayesian inference and singular value decomposition inversion are compared and contrasted.

Quantification of CO2 and CH4 megacity emissions using portable solar absorption spectrometers

NASA Astrophysics Data System (ADS)

Frey, Matthias; Hase, Frank; Blumenstock, Thomas; Morino, Isamu; Shiomi, Kei

2017-04-01

Urban areas already contribute to over 50% of the global population, additionally the percentage of the worldwide population living in Metropolitan areas is continuously growing. Thus, a precise knowledge of urban greenhouse gas (GHG) emissions is of utmost importance. Whereas, however, GHG emissions on a nationwide to continental scale can be relatively precisely estimated using satellite observations (and fossil fuel consumption statistics), reliable estimations for local to regional scale emissions pose a bigger problem due to lack of timely and spatially high resolved satellite data and possible biases of passive spectroscopic nadir observations (e.g. enhanced aerosol scattering in a city plume). Furthermore, emission inventories on the city scale might be missing contributions (e.g. methane leakage from gas pipes). Here, newly developed mobile low resolution Fourier Transform spectrometers (Bruker EM27/SUN) are utilized to quantify small scale emissions. This novel technique was successfully tested before by KIT and partners during campaigns in Berlin, Paris and Colorado for detecting emissions from various sources. We present results from a campaign carried out in February - April 2016 in the Tokyo bay area, one of the biggest Metropolitan areas worldwide. We positioned two EM27/SUN spectrometers on the outer perimeter of Tokyo along the prevailing wind axis upwind and downwind of the city source. Before and after the campaign, calibration measurements were performed in Tsukuba with a collocated high resolution FTIR spectrometer from the Total Carbon Column Observing Network (TCCON). During the campaign the observed XCO2 and XCH4 values vary significantly. Additionally, intraday variations are observed at both sites. Furthermore, an enhancement due to the Tokyo area GHG emissions is clearly visible for both XCO2 and XCH4. The observed signals are significantly higher compared to prior campaigns targeting other major cities. We perform a rough estimate of the source strength. Finally, a comparison with an observation from the OCO-2 satellite is shown.

Quantifying emissions of NH3 and NOx from Agricultural Sources and Biomass Burning using SOF

NASA Astrophysics Data System (ADS)

Kille, N.; Volkamer, R. M.; Dix, B. K.

2017-12-01

Column measurements of trace gas absorption along the direct solar beam present a powerful yet underused approach to quantify emission fluxes from area sources. The University of Colorado Solar Occultation Flux (CU SOF) instrument (Kille et al., 2017, AMT, doi:10.5194/amt-10-373-2017) features a solar tracker that is self-positioning for use from mobile platforms that are in motion (Baidar et al., 2016, AMT, doi: 10.5194/amt-9-963-2016). This enables the use from research aircraft, as well as the deployment under broken cloud conditions, while making efficient use of aircraft time. First airborne SOF measurements have been demonstrated recently, and we discuss applications to study emissions from biomass burning using aircraft, and to study primary emissions of ammonia and nitrogen oxides (= NO + NO2) from area sources such as concentrated animal feeding operations (CAFO). SOF detects gases in the open atmosphere (no inlets), does not require access to the source, and provides results in units that can be directly compared with emission inventories. The method of emission quantification is relatively straightforward. During FRAPPE (Front Range Air Pollution and Photochemistry Experiment) in Colorado in 2014, we measured emission fluxes of NH3, and NOx from CAFO, quantifying the emissions from 61400 of the 535766 cattle in Weld County, CO (11.4% of the cattle population). We find that NH3 emissions from dairy and cattle farms are similar after normalization by the number of cattle, i.e., we find emission factors, EF, of 11.8 ± 2.0 gNH3/h/head for the studied CAFOs; these EFs are at the upper end of reported values. Results are compared to daytime NEI emissions for case study days. Furthermore, biologically active soils are found to be a strong source of NOx. The NOx sources account for 1.2% of the N-flux (i.e., NH3), and can be competitive with other NOx sources in Weld, CO. The added NOx is particularly relevant in remote regions, where O3 formation and oxidative capacity is NOx limited.

Identification and elucidation of anthropogenic source contribution in PM10 pollutant: Insight gain from dispersion and receptor models.

PubMed

Roy, Debananda; Singh, Gurdeep; Yadav, Pankaj

2016-10-01

Source apportionment study of PM 10 (Particulate Matter) in a critically polluted area of Jharia coalfield, India has been carried out using Dispersion model, Principle Component Analysis (PCA) and Chemical Mass Balance (CMB) techniques. Dispersion model Atmospheric Dispersion Model (AERMOD) was introduced to simplify the complexity of sources in Jharia coalfield. PCA and CMB analysis indicates that monitoring stations near the mining area were mainly affected by the emission from open coal mining and its associated activities such as coal transportation, loading and unloading of coal. Mine fire emission also contributed a considerable amount of particulate matters in monitoring stations. Locations in the city area were mostly affected by vehicular, Liquid Petroleum Gas (LPG) & Diesel Generator (DG) set emissions, residential, and commercial activities. The experimental data sampling and their analysis could aid understanding how dispersion based model technique along with receptor model based concept can be strategically used for quantitative analysis of Natural and Anthropogenic sources of PM 10 . Copyright © 2016. Published by Elsevier B.V.

Photochemical modeling of emissions trading of highly reactive volatile organic compounds in Houston, Texas. 2. Incorporation of chlorine emissions.

PubMed

Wang, Linlin; Thompson, Tammy; McDonald-Buller, Elena C; Allen, David T

2007-04-01

As part of the State Implementation Plan for attaining the National Ambient Air Quality Standard for ozone, the Texas Commission of Environmental Quality has created a Highly Reactive Volatile Organic Compounds (HRVOC) Emissions Cap and Trade Program for industrial point sources in the Houston/Galveston/Brazoria area. This series of papers examines the potential air quality impacts of this new emission trading program through photochemical modeling of potential trading scenarios; this paper examines the air quality impact of allowing facilities to trade chlorine emission reductions for HRVOC allocations on a reactivity weighted basis. The simulations indicate that trading of anthropogenic chlorine emission reductions for HRVOC allowances at a single facility or between facilities, in general, resulted in improvements in air quality. Decreases in peak 1-h averaged and 8-h averaged ozone concentrations associated with trading chlorine emissions for HRVOC allocations on a Maximum Incremental Reactivity (MIR) basis were up to 0.74 ppb (0.63%) and 0.56 ppb (0.61%), respectively. Air quality metrics based on population exposure decreased by up to 3.3% and 4.1% for 1-h and 8-h averaged concentrations. These changes are small compared to the maximum changes in ozone concentrations due to the VOC emissions from these sources (5-10 ppb for 8-h averages; up to 30 ppb for 1-h averages) and the chlorine emissions from the sources (5-10 ppb for maximum concentrations over wide areas and up to 70 ppb in localized areas). The simulations indicate that the inclusion of chlorine emissions in the trading program is likely to be beneficial to air quality and is unlikely to cause localized increases in ozone concentrations ("hot spots").

Mercury emission to the atmosphere from municipal solid waste landfills: A brief review

NASA Astrophysics Data System (ADS)

Tao, Zhengkai; Dai, Shijin; Chai, Xiaoli

2017-12-01

Municipal solid waste (MSW) landfill is regarded as an important emission source of atmospheric mercury (Hg), which is associated with potential health and environmental risks, as outlined by the Minamata Convention on Hg. This review presents the current state of knowledge with regards to landfill Hg sources, Hg levels in MSW and cover soils, Hg emission to the atmosphere, available Hg biogeochemical transformations, research methods for Hg emission, and important areas for future research. In addition, strategies for controlling landfill Hg emissions are considered, including reducing the Hg load in landfill and in situ controls. These approaches mainly focus on Hg source reduction, Hg recycling programs, public education, and in situ technology such as timely soil cover, vegetation, and end-of-pipe technology for controlling Hg emission from landfill gas.

A cautionary tale: A study of a methane enhancement over the North Sea

NASA Astrophysics Data System (ADS)

Cain, M.; Warwick, N. J.; Fisher, R. E.; Lowry, D.; Lanoisellé, M.; Nisbet, E. G.; France, J.; Pitt, J.; O'Shea, S.; Bower, K. N.; Allen, G.; Illingworth, S.; Manning, A. J.; Bauguitte, S.; Pisso, I.; Pyle, J. A.

2017-07-01

Airborne measurements of a methane (CH4) plume over the North Sea from August 2013 are analyzed. The plume was only observed downwind of circumnavigated gas fields, and three methods are used to determine its source. First, a mass balance calculation assuming a gas field source gives a CH4 emission rate between 2.5 ± 0.8×104 and 4.6 ± 1.5×104 kg h-1. This would be greater than the industry's reported 0.5% leak rate if it were emitting for more than half the time. Second, annual average UK CH4 emissions are combined with an atmospheric dispersion model to create pseudo-observations. Clean air from the North Atlantic passed over mainland UK, picking up anthropogenic emissions. To best explain the observed plume using pseudo-observations, an additional North Sea source from the gas rigs area is added. Third, the δ13C-CH4 from the plume is shown to be -53‰, which is lighter than fossil gas but heavier than the UK average emission. We conclude that either an additional small-area mainland source is needed, combined with temporal variability in emission or transport in small-scale meteorological features. Alternatively, a combination of additional sources that are at least 75% from the mainland (-58‰) and up to 25% from the North Sea gas rigs area (-32‰) would explain the measurements. Had the isotopic analysis not been performed, the likely conclusion would have been of a gas field source of CH4. This demonstrates the limitation of analyzing mole fractions alone, as the simplest explanation is rejected based on analysis of isotopic data.

75 FR 522 - National Emission Standards for Hazardous Air Pollutants: Area Source Standards for Prepared...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-05

... to what constitutes the generally available control technology or management practices for the area... area sources, pose the greatest threat to public health in the largest number of urban areas. EPA implemented this provision in 1999 in the Integrated Urban Air Toxics Strategy, (64 FR 38715, July 19, 1999...

Quantifying the emissions of HCN from on-road vehicles in urban areas

NASA Astrophysics Data System (ADS)

Moussa, S. G.; Leithead, A.; Wentzell, J. J.; Lu, G.; Li, S.; Brook, J.; Liggio, J.

2013-12-01

Hydrogen Cyanide (HCN), has been considered a marker for biomass burning emissions. Despite its adverse health impacts, estimate of its global sources and sinks are highly uncertain due to a limited number of field and laboratory studies. In particular, HCN emissions from automobile exhaust are not well constrained for modern vehicles, and thought to be relatively small compared to emissions from biomass burning. In the current study, HCN emissions from individual diesel and gasoline vehicles were quantified as a function of engine driving mode, and fuel type. Proton transfer Reaction-Time of Flight-Mass spectrometry (PTR-ToF-MS) was used to measure HCN emissions from diesel engines operating on ultra-low sulfur diesel (ULSD) and various bio-diesel blends including Soy, Tallow, and Canola. Significant emissions of HCN were observed from all vehicles, and enhanced with the use of biodiesel. In addition, ambient measurements of HCN in a traffic dominated urban area in Toronto, Canada demonstrated that a correlation between HCN, and traditional vehicle emissions markers such as benzene and xylenes exists and indicating that HCN has the potential to be a marker of fuel combustion. The ambient data and the calculated emission factors further suggest that vehicular emissions are a major source of HCN even in the presence of biomass burning, and that near roadway conditions may represent the dominant exposure pathway to HCN in urban areas. Results of this study have important implications on HCN global budget, health impacts in urban areas and the effect of alternate fuels on the emissions of this toxic species.

Solar radio continuum storms and a breathing magnetic field model

NASA Technical Reports Server (NTRS)

1975-01-01

Radio noise continuum emissions observed in metric and decametric wave frequencies are, in general, associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. These continuum emission sources, often called type I storm sources, are often associated with type III burst storm activity from metric to hectometric wave frequencies. This storm activity is, therefore, closely connected with the development of these continuum emission sources. It is shown that the S-component emission in microwave frequencies generally precedes, by several days, the emission of these noise continuum storms of lower frequencies. In order for these storms to develop, the growth of sunspot groups into complex types is very important in addition to the increase of the average magnetic field intensity and area of these groups. After giving a review on the theory of these noise continuum storm emissions, a model is briefly considered to explain the relation of the emissions to the storms.

Near-source mobile methane emission estimates using EPA Method33a and a novel probabilistic approach as a basis for leak quantification in urban areas

NASA Astrophysics Data System (ADS)

Albertson, J. D.

2015-12-01

Methane emissions from underground pipeline leaks remain an ongoing issue in the development of accurate methane emission inventories for the natural gas supply chain. Application of mobile methods during routine street surveys would help address this issue, but there are large uncertainties in current approaches. In this paper, we describe results from a series of near-source (< 30 m) controlled methane releases where an instrumented van was used to measure methane concentrations during both fixed location sampling and during mobile traverses immediately downwind of the source. The measurements were used to evaluate the application of EPA Method 33A for estimating methane emissions downwind of a source and also to test the application of a new probabilistic approach for estimating emission rates from mobile traverse data.

Evaluating the impact of improvements to the FLAMBE smoke source model on forecasts of aerosol distribution from NAAPS

NASA Astrophysics Data System (ADS)

Hyer, E. J.; Reid, J. S.

2006-12-01

As more forecast models aim to include aerosol and chemical species, there is a need for source functions for biomass burning emissions that are accurate, robust, and operable in real-time. NAAPS is a global aerosol forecast model running every six hours and forecasting distributions of biomass burning, industrial sulfate, dust, and sea salt aerosols. This model is run operationally by the U.S. Navy as an aid to planning. The smoke emissions used as input to the model are calculated from the data collected by the FLAMBE system, driven by near-real-time active fire data from GOES WF_ABBA and MODIS Rapid Response. The smoke source function uses land cover data to predict properties of detected fires based on literature data from experimental burns. This scheme is very sensitive to the choice of land cover data sets. In areas of rapid land cover change, the use of static land cover data can produce artifactual changes in emissions unrelated to real changes in fire patterns. In South America, this change may be as large as 40% over five years. We demonstrate the impact of a modified land cover scheme on FLAMBE emissions and NAAPS forecasts, including a fire size algorithm developed using MODIS burned area data. We also describe the effects of corrections to emissions estimates for cloud and satellite coverage. We outline areas where existing data sources are incomplete and improvements are required to achieve accurate modeling of biomass burning emissions in real time.

National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Area Source Standards for Prepared Feeds Manufacturing: Commonly Asked Questions and Answers

EPA Pesticide Factsheets

This 2011 document answers common questions about the NESHAP for Area Sources for Prepared Feeds Manufacturing. The questions range in topics including applicability, specific requirements, and recordkeeping.

77 FR 51930 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Attainment Plan for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-28

... for the Philadelphia Area. While the monitoring data that show the Philadelphia Area attained the 1997... sources (such as cargo handling equipment) at ports. Activity data for land-based sources collected from... emission estimates. EPA also verified that land-based sources for cargo handling equipment, such as...

ION SOURCE FOR CALUTRONS

DOEpatents

Tolmie, J.R.

1958-09-16

An improvement is presented in ion sources of the type employed in calutron devices. The described ion source has for its inventive contribution the incorporation of a plate-like cathode having the general configuration of a polygon including a given number of apices. When a polyphase source of current has a phase connected to each of the apices, the cathode is heated and rendered electron emissive. This particular cathode configuration is of sturdy construction and provides unuform emission over a considerable area.

Network design for quantifying urban CO2 emissions: assessing trade-offs between precision and network density

NASA Astrophysics Data System (ADS)

Turner, Alexander J.; Shusterman, Alexis A.; McDonald, Brian C.; Teige, Virginia; Harley, Robert A.; Cohen, Ronald C.

2016-11-01

The majority of anthropogenic CO2 emissions are attributable to urban areas. While the emissions from urban electricity generation often occur in locations remote from consumption, many of the other emissions occur within the city limits. Evaluating the effectiveness of strategies for controlling these emissions depends on our ability to observe urban CO2 emissions and attribute them to specific activities. Cost-effective strategies for doing so have yet to be described. Here we characterize the ability of a prototype measurement network, modeled after the Berkeley Atmospheric CO2 Observation Network (BEACO2N) in California's Bay Area, in combination with an inverse model based on the coupled Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) to improve our understanding of urban emissions. The pseudo-measurement network includes 34 sites at roughly 2 km spacing covering an area of roughly 400 km2. The model uses an hourly 1 × 1 km2 emission inventory and 1 × 1 km2 meteorological calculations. We perform an ensemble of Bayesian atmospheric inversions to sample the combined effects of uncertainties of the pseudo-measurements and the model. We vary the estimates of the combined uncertainty of the pseudo-observations and model over a range of 20 to 0.005 ppm and vary the number of sites from 1 to 34. We use these inversions to develop statistical models that estimate the efficacy of the combined model-observing system in reducing uncertainty in CO2 emissions. We examine uncertainty in estimated CO2 fluxes on the urban scale, as well as for sources embedded within the city such as a line source (e.g., a highway) or a point source (e.g., emissions from the stacks of small industrial facilities). Using our inversion framework, we find that a dense network with moderate precision is the preferred setup for estimating area, line, and point sources from a combined uncertainty and cost perspective. The dense network considered here (modeled after the BEACO2N network with an assumed mismatch error of 1 ppm at an hourly temporal resolution) could estimate weekly CO2 emissions from an urban region with less than 5 % error, given our characterization of the combined observation and model uncertainty.

Network design for quantifying urban CO 2 emissions: assessing trade-offs between precision and network density

DOE PAGES

Turner, Alexander J.; Shusterman, Alexis A.; McDonald, Brian C.; ...

2016-11-01

The majority of anthropogenic CO 2 emissions are attributable to urban areas. While the emissions from urban electricity generation often occur in locations remote from consumption, many of the other emissions occur within the city limits. Evaluating the effectiveness of strategies for controlling these emissions depends on our ability to observe urban CO 2 emissions and attribute them to specific activities. Cost-effective strategies for doing so have yet to be described. Here we characterize the ability of a prototype measurement network, modeled after the Berkeley Atmospheric CO 2 Observation Network (BEACO 2N) in California's Bay Area, in combination with anmore » inverse model based on the coupled Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) to improve our understanding of urban emissions. The pseudo-measurement network includes 34 sites at roughly 2 km spacing covering an area of roughly 400 km 2. The model uses an hourly 1 × 1 km 2 emission inventory and 1 × 1 km 2 meteorological calculations. We perform an ensemble of Bayesian atmospheric inversions to sample the combined effects of uncertainties of the pseudo-measurements and the model. We vary the estimates of the combined uncertainty of the pseudo-observations and model over a range of 20 to 0.005 ppm and vary the number of sites from 1 to 34. We use these inversions to develop statistical models that estimate the efficacy of the combined model–observing system in reducing uncertainty in CO 2 emissions. We examine uncertainty in estimated CO 2 fluxes on the urban scale, as well as for sources embedded within the city such as a line source (e.g., a highway) or a point source (e.g., emissions from the stacks of small industrial facilities). Using our inversion framework, we find that a dense network with moderate precision is the preferred setup for estimating area, line, and point sources from a combined uncertainty and cost perspective. The dense network considered here (modeled after the BEACO 2N network with an assumed mismatch error of 1 ppm at an hourly temporal resolution) could estimate weekly CO 2 emissions from an urban region with less than 5 % error, given our characterization of the combined observation and model uncertainty.« less

Network design for quantifying urban CO 2 emissions: assessing trade-offs between precision and network density

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Alexander J.; Shusterman, Alexis A.; McDonald, Brian C.

The majority of anthropogenic CO 2 emissions are attributable to urban areas. While the emissions from urban electricity generation often occur in locations remote from consumption, many of the other emissions occur within the city limits. Evaluating the effectiveness of strategies for controlling these emissions depends on our ability to observe urban CO 2 emissions and attribute them to specific activities. Cost-effective strategies for doing so have yet to be described. Here we characterize the ability of a prototype measurement network, modeled after the Berkeley Atmospheric CO 2 Observation Network (BEACO 2N) in California's Bay Area, in combination with anmore » inverse model based on the coupled Weather Research and Forecasting/Stochastic Time-Inverted Lagrangian Transport (WRF-STILT) to improve our understanding of urban emissions. The pseudo-measurement network includes 34 sites at roughly 2 km spacing covering an area of roughly 400 km 2. The model uses an hourly 1 × 1 km 2 emission inventory and 1 × 1 km 2 meteorological calculations. We perform an ensemble of Bayesian atmospheric inversions to sample the combined effects of uncertainties of the pseudo-measurements and the model. We vary the estimates of the combined uncertainty of the pseudo-observations and model over a range of 20 to 0.005 ppm and vary the number of sites from 1 to 34. We use these inversions to develop statistical models that estimate the efficacy of the combined model–observing system in reducing uncertainty in CO 2 emissions. We examine uncertainty in estimated CO 2 fluxes on the urban scale, as well as for sources embedded within the city such as a line source (e.g., a highway) or a point source (e.g., emissions from the stacks of small industrial facilities). Using our inversion framework, we find that a dense network with moderate precision is the preferred setup for estimating area, line, and point sources from a combined uncertainty and cost perspective. The dense network considered here (modeled after the BEACO 2N network with an assumed mismatch error of 1 ppm at an hourly temporal resolution) could estimate weekly CO 2 emissions from an urban region with less than 5 % error, given our characterization of the combined observation and model uncertainty.« less

Emissions of black carbon and co-pollutants emitted from diesel vehicles in the Mexico City Metropolitan Area

NASA Astrophysics Data System (ADS)

Zavala, Miguel; Molina, Luisa T.; Fortner, Edward; Knighton, Berk; Herndon, Scott; Yacovitch, Tara; Floerchinger, Cody; Roscioli, Joseph; Kolb, Charles; Mejia, Jose Antonio; Sarmiento, Jorge; Paramo, Victor Hugo; Zirath, Sergio; Jazcilevich, Aron

2014-05-01

Black carbon emitted from freight, public transport, and heavy duty trucks sources is linked with adverse effects on human health. In addition, the control of emissions of black carbon, an important short-lived climate forcing agent (SLCF), has recently been considered as one of the key strategies for mitigating regional near-term climate change. Despite the availability of new emissions control technologies for reducing emissions from diesel-powered mobile sources, their introduction is still not widespread in many urban areas and there is a need to characterize real-world emission rates of black carbon from this key source. The emissions of black carbon, organic carbon, and other gaseous and particle pollutants from diesel-powered mobile sources in Mexico were characterized by deploying a mobile laboratory equipped with real-time instrumentation in Mexico City as part of the SLCFs-Mexico 2013 project. From February 25-28 of 2013 the emissions from selected diesel-powered vehicles were measured in both controlled experiments and real-world on-road driving conditions. Sampled vehicles had several emissions levels technologies, including: EPA98, EPA03, EPA04, EURO3-5, and Hybrid. All vehicles were sampled using diesel fuel and several vehicles were measured using both diesel and biodiesel fuels. Additional measurements included the use of a remote sensing unit for the co-sampling of all tested vehicles, and the installation and operation of a Portable Emissions Measurements System (PEMS) for the measurement of emissions from a test vehicle. We will present inter-comparisons of the emission factors obtained among the various vehicle technologies that were sampled during the experiment as well as the inter-comparison of results from the various sampling platforms. The results can be used to

Computer-oriented emissions inventory procedure for urban and industrial sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Runca, E.; Zannetti, P.; Melli, P.

1978-06-01

A knowledge of the rate of emission of atmospheric pollutants is essential for the enforcement of air quality control policies. A computer-oriented emission inventory procedure has been developed and applied to Venice, Italy. By using optically readable forms this procedure avoids many of the errors inherent in the transcription and punching steps typical of approaches applied so far. Moreover, this procedure allows an easy updating of the inventory. Emission patterns of SO/sub 2/ in the area of Venice showed that the total urban emissions were about 6% of those emitted by industrial sources.

Integral emission factors for methane determined using urban flux measurements and local-scale inverse models

NASA Astrophysics Data System (ADS)

Christen, Andreas; Johnson, Mark; Molodovskaya, Marina; Ketler, Rick; Nesic, Zoran; Crawford, Ben; Giometto, Marco; van der Laan, Mike

2013-04-01

The most important long-lived greenhouse gas (LLGHG) emitted during combustion of fuels is carbon dioxide (CO2), however also traces of the LLGHGs methane (CH4) and nitrous oxide (N2O) are released, the quantities of which depend largely on the conditions of the combustion process. Emission factors determine the mass of LLGHGs emitted per energy used (or kilometre driven for cars) and are key inputs for bottom-up emission modelling. Emission factors for CH4 are typically determined in the laboratory or on a test stand for a given combustion system using a small number of samples (vehicles, furnaces), yet associated with larger uncertainties when scaled to entire fleets. We propose an alternative, different approach - Can integrated emission factors be independently determined using direct micrometeorological flux measurements over an urban surface? If so, do emission factors determined from flux measurements (top-down) agree with up-scaled emission factors of relevant combustion systems (heating, vehicles) in the source area of the flux measurement? Direct flux measurements of CH4 were carried out between February and May, 2012 over a relatively densely populated, urban surface in Vancouver, Canada by means of eddy covariance (EC). The EC-system consisted of an ultrasonic anemometer (CSAT-3, Campbell Scientific Inc.) and two open-path infrared gas analyzers (Li7500 and Li7700, Licor Inc.) on a tower at 30m above the surface. The source area of the EC system is characterised by a relative homogeneous morphometry (5.3m average building height), but spatially and temporally varying emission sources, including two major intersecting arterial roads (70.000 cars drive through the 50% source area per day) and seasonal heating in predominantly single-family houses (natural gas). An inverse dispersion model (turbulent source area model), validated against large eddy simulations (LES) of the urban roughness sublayer, allows the determination of the spatial area that contributes to each measurement interval (30 min), which varies with wind direction and stability. A detailed geographic information system of the urban surface combined with traffic counts and building energy models makes it possible to statistically relate fluxes to vehicle density (km driven) and buildings (gas heated volume) - and ultimately quantify the contribution of space heating, transport sector and fugitive emissions to the total emitted CH4 from an urban environment. The measured fluxes of CH4 over the selected urban environment averaged to 22.8 mg CH4 m-2 day-1 during the study period. Compared with the simultaneously measured CO2 emissions, the contribution of CH4, however, accounts for only about 3% of the total LLGHG emissions from this particular urban surface. Traffic contributed 8.8 mg CH4 m-2 day-1, equivalent to 39% of the total CH4 flux. The determined emission factor for the typical fleet composition is 0.062 g CH4 per km driven which is higher than upscaled fleet emission factors (EPA) by a factor of two. This discrepancy can be partially explained through the slower city traffic with frequent idling (traffic congestion), fleet composition and cold starts. Emissions of CH4 by domestic space heating (55% of the total CH4 flux or 12.7 mg CH4 m-2 day-1) are also higher than estimated from upscaled emission factors. There is no evidence of substantial unknown sources such as soil processes, combustion of wood, and leakages from gas distribution pipes (residual: 6% or 1.3 mg CH4 m-2 day-1). The presented study is among the first direct measurements of CH4 emissions over an urban surface and demonstrates that flux measurements of greenhouse gases can be used to determine sources and emission factors in complex urban situations.

Probabilistic location estimation of acoustic emission sources in isotropic plates with one sensor

NASA Astrophysics Data System (ADS)

Ebrahimkhanlou, Arvin; Salamone, Salvatore

2017-04-01

This paper presents a probabilistic acoustic emission (AE) source localization algorithm for isotropic plate structures. The proposed algorithm requires only one sensor and uniformly monitors the entire area of such plates without any blind zones. In addition, it takes a probabilistic approach and quantifies localization uncertainties. The algorithm combines a modal acoustic emission (MAE) and a reflection-based technique to obtain information pertaining to the location of AE sources. To estimate confidence contours for the location of sources, uncertainties are quantified and propagated through the two techniques. The approach was validated using standard pencil lead break (PLB) tests on an Aluminum plate. The results demonstrate that the proposed source localization algorithm successfully estimates confidence contours for the location of AE sources.

Stochastic industrial source detection using lower cost methods

EPA Science Inventory

Hazardous air pollutants (HAPs) can be emitted from a variety of sources in industrial facilities, energy production, and commercial operations. Stochastic industrial sources (SISs) represent a subcategory of emissions from fugitive leaks, variable area sources, malfunctioning p...

A systematic review of the physical and chemical characteristics of pollutants from biomass burning and combustion of fossil fuels and health effects in Brazil.

PubMed

Oliveira, Beatriz Fátima Alves de; Ignotti, Eliane; Hacon, Sandra S

2011-09-01

The aim of this study was to carry out a review of scientific literature published in Brazil between 2000 and 2009 on the characteristics of air pollutants from different emission sources, especially particulate matter (PM) and its effects on respiratory health. Using electronic databases, a systematic literature review was performed of all research related to air pollutant emissions. Publications were analyzed to identify the physical and chemical characteristics of pollutants from different emission sources and their related effects on the respiratory system. The PM2.5 is composed predominantly of organic compounds with 20% of inorganic elements. Higher concentrations of metals were detected in metropolitan areas than in biomass burning regions. The relative risk of hospital admissions due to respiratory diseases in children was higher than in the elderly population. The results of studies of health effects of air pollution are specific to the region where the emissions occurred and should not be used to depict the situation in other areas with different emission sources.

Occurrence of chloromethane in tropical terrestrial and marine areas

NASA Astrophysics Data System (ADS)

Laturnus, F.; Kolusu, S.; Grawe, D.; Mehlig, U.; Asp, N.; Schlünzen, K. H.; Seifert, R.

2011-12-01

The discussion of a possible global climate change induced by human activities brought sources into focus not yet considered to be important in global climate changes. One source is the natural emission of chloromethane, a compound which is known to participate in atmospheric processes affecting the global climate, such as stratospheric ozone destruction and warming of the troposphere. Especially natural emissions of chloromethane have been under scrutiny recently as the part of the natural contribution is still unknown and may be influenced by human activities. A comparison between global atmospheric occurrence of chloromethane and their input from so far known industrial and natural sources revealed a gap of 40-50% in missing input. Recently, it has been suggested that tropical areas may be the missing link in filling the gap of the atmospheric input of chloromethane. In our studies, we investigated tropical oceanic areas and mangrove forests regarding their occurrence and emission of chloromethane. For the oceanic areas, ambient air concentrations and stable carbon rations were taken. Together with backward air mass trajectory analysis the results revealed a coastal influence on the occurrence of chloromethane in the tropical ocean. For the mangrove forest areas, ambient air concentrations and stable carbon rations were taken at upwind and downwind position at the coast of Brazil. The results showed a considerable natural emission of chloromethane suggesting mangroves as an important source for the atmospheric input of chloromethane. With the help of a mesoscale atmospheric model meteorological conditions were simulated and the fluxes of chloromethane from mangrove forest were estimated.

Emissions from Plug-in Hybrid Electric Vehicle (PHEV) During Real World Driving Under Various Weather Conditions

DOT National Transportation Integrated Search

2018-02-02

Exposure to particulate matter (PM) and pollutant gas (NOx) is associated with increased cardiopulmonary morbidity and mortality. Mobile source emissions contribute to PM and NOx emissions significantly in urban areas. Hybrid Electric Vehicles (HEVs)...

EMISSIONS FROM STREET VENDOR COOKING DEVICES (CHARCOAL GRILLING)

EPA Science Inventory

The report discusses a joint U.S./Mexican program to establish a reliable emissions inventory for street vendor cooking devices (charcoal grilling), a significant source of air pollutants in the Mexicali-Imperial Valley area of Mexico. Emissions from these devices, prevalent in t...

Wide area methane emissions mapping with airborne IPDA lidar

NASA Astrophysics Data System (ADS)

Bartholomew, Jarett; Lyman, Philip; Weimer, Carl; Tandy, William

2017-08-01

Methane emissions from natural gas production, storage, and transportation are potential sources of greenhouse gas emissions. Methane leaks also constitute revenue loss potential from operations. Since 2013, Ball Aerospace has been developing advanced airborne sensors using integrated path differential absorption (IPDA) LIDAR instrumentation to identify methane, propane, and longer-chain alkanes in the lowest region of the atmosphere. Additional funding has come from the U.S. Department of Transportation, Pipeline and Hazardous Materials Administration (PHMSA) to upgrade instrumentation to a broader swath coverage of up to 400 meters while maintaining high spatial sampling resolution and geolocation accuracy. Wide area coverage allows efficient mapping of emissions from gathering and distribution networks, processing facilities, landfills, natural seeps, and other distributed methane sources. This paper summarizes the benefits of advanced instrumentation for aerial methane emission mapping, describes the operating characteristics and design of this upgraded IPDA instrumentation, and reviews technical challenges encountered during development and deployment.

Mobile Optical Remote Sensing Measurements of VOC's to Quantify Emissions and to Map Impact

NASA Astrophysics Data System (ADS)

Mellqvist, J.; Samuelsson, J.; Marianne, E.; Brohede, S.; Andersson, P.; Johansson, J.; Izos, O.; Polidori, A.; Pikelnaya, O.

2017-12-01

Industrial volatile organic compound (VOC) emissions may cause direct health problems and contribute significantly to ozone formation. In order to investigate how small sources contribute to the VOC concentrations in the Los Angeles metropolitan area a comprehensive emission study has been carried out on behalf of the South Coast Air Quality Management District (SCAQMD). Emission measurements of alkanes, alkenes, aromatic VOCs and methane from major sources such as refineries, oil wells, petrol stations oil depots and oil platforms were measured in an intensive campaign during the fall of 2015 using several unique optical methods, including the Solar Occultation Flux method (SOF) and tracer correlation technique based on extractive FTIR and DOAS combined with an open path multi reflection cell. In 2017 these measurements have been continued during four shorter campaigns on several of the identified hot spot emission sites. The objective has been to study the time evolution and annual variation of the emission sources and their impact on the surroundings. The latter has been carried out by mobile mapping of VOC concentrations downwind of the sources and comparison to low cost portable PID sensors. The results from the field campaigns show that the emissions from the above mentioned sources are largely underestimated in inventories with potential impact on the air quality in the Los Angeles metropolitan area. In this presentation we will describe the optical techniques and describe recent standardization work carried out in Europe and the US. In addition, results from the measurements in the LA-basin will be shown and discussed.

Greenhouse Gas (GHG) Source Detection and Attribution in the San Francisco Bay Area of California Using a Mobile Measurement Platform

NASA Astrophysics Data System (ADS)

Guha, A.; Bower, J.; Martien, P. T.; Perkins, I.; Randall, S.; Stevenson, E.; Young, A.; Hilken, H.

2016-12-01

The Bay Area Air Quality Management District is the greater San Francisco Bay metropolitan area's chief air quality regulatory agency. Aligning itself with the Governor's Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 2016 Clean Air Plan will lay out the agency's vision and actions to put the region on a path forward towards achieving the 2050 goal while also reducing air pollution and related health impacts. The 2016 Plan has three overarching objectives: 1) develop a multi-pollutant emissions control strategy, (2) reduce population exposure to harmful air pollutants, especially in vulnerable communities, and (3) protect climate through a comprehensive Regional Climate Protection Strategy. To accomplish one of 2016 Plan's control measures (SL3 - Greenhouse Gas Monitoring and Measurement Network), the Air District has fabricated a mobile measurement platform i.e. a GHG research van to perform targeted CH4 emissions hotspot detection and source attribution. The van is equipped with analyzers capable of measuring CH4, CO2 and N2O in ambient plumes at fast sampling rates. The coincident measurement of source tracers like isotopic methane (13C - CH4), CO and ethane (C2H6) provide the capability to distinguish between biogenic, combustion-based and fossil-based fugitive methane sources, respectively. The GHG research van is a comprehensive mobile tool to perform tracer-based GHG source identification and apportionment. We report observation-based source-specific tracer-to-tracer emission ratios from a region-wide survey of well-known area sources like landfills, wastewater treatment facilities and dairies, and compare those with similar ratios in the Air District's GHG inventory. We also investigate plumes from potentially under-inventoried sources like anaerobic digesters, composting operations, active and plugged oil and gas wells, and a natural gas storage facility. Data from source-specific measurements will lead to an improved understanding of GHG emissions from well-known and lesser-known CH4 sources in the region, which is key in resolving the differences between top-down regional estimates (Fairley and Fischer, 2015; Jeong et al., in prep) and the regional bottom-up inventory.

Fact Sheets: Air Toxics Standards for Area Sources in Seven Industry Sectors

EPA Pesticide Factsheets

This page contains a June 2007 fact sheet and a March 2008 fact sheet for the National Emission Standards for Hazardous Air Pollutants (NESHAP): Wood Preserving Area Sources. These documents provide a summary of the information for this NESHAP.

Source apportionment vs. emission inventories of non-methane hydrocarbons (NMHC) in an urban area of the Middle East: local and global perspectives

NASA Astrophysics Data System (ADS)

Salameh, T.; Sauvage, S.; Afif, C.; Borbon, A.; Locoge, N.

2015-10-01

We applied the Positive Matrix Factorization model to two large datasets collected during two intensive measurement campaigns (summer 2011 and winter 2012) at a sub-urban site in Beirut, Lebanon, in order to identify NMHC sources and quantify their contribution to ambient levels. Six factors were identified in winter and five factors in summer. PMF-resolved source profiles were consistent with source profiles established by near-field measurements. The major sources were traffic-related emissions (combustion and gasoline evaporation) in winter and in summer accounting for 51 and 74 wt % respectively in agreement with the national emission inventory. The gasoline evaporation related to traffic source had a significant contribution regardless of the season (22 wt % in winter and 30 wt % in summer). The NMHC emissions from road transport are estimated from observations and PMF results, and compared to local and global emission inventories. The national road transport inventory shows lowest emissions than the ones from PMF but with a reasonable difference lower than 50 %. Global inventories show higher discrepancies with lower emissions up to a factor of 10 for the transportation sector. When combining emission inventory to our results, there is a strong evidence that control measures in Lebanon should be targeted on mitigating the NMHC emissions from the traffic-related sources. From a global perspective, an assessment of VOC anthropogenic emission inventories for the Middle East region as a whole seems necessary as these emissions could be much higher than expected at least from the road transport sector. Highlights: - PMF model was applied to identify major NMHC sources and their seasonal variation. - Gasoline evaporation accounts for more than 40 % both in winter and in summer. - NMHC urban emissions are dominated by traffic related sources in both seasons. - Agreement with the emission inventory regarding the relative contribution of the on-road mobile source but disagreement in terms of emission quantities suggesting an underestimation of the inventories.

Validation of a novel air toxic risk model with air monitoring.

PubMed

Pratt, Gregory C; Dymond, Mary; Ellickson, Kristie; Thé, Jesse

2012-01-01

Three modeling systems were used to estimate human health risks from air pollution: two versions of MNRiskS (for Minnesota Risk Screening), and the USEPA National Air Toxics Assessment (NATA). MNRiskS is a unique cumulative risk modeling system used to assess risks from multiple air toxics, sources, and pathways on a local to a state-wide scale. In addition, ambient outdoor air monitoring data were available for estimation of risks and comparison with the modeled estimates of air concentrations. Highest air concentrations and estimated risks were generally found in the Minneapolis-St. Paul metropolitan area and lowest risks in undeveloped rural areas. Emissions from mobile and area (nonpoint) sources created greater estimated risks than emissions from point sources. Highest cancer risks were via ingestion pathway exposures to dioxins and related compounds. Diesel particles, acrolein, and formaldehyde created the highest estimated inhalation health impacts. Model-estimated air concentrations were generally highest for NATA and lowest for the AERMOD version of MNRiskS. This validation study showed reasonable agreement between available measurements and model predictions, although results varied among pollutants, and predictions were often lower than measurements. The results increased confidence in identifying pollutants, pathways, geographic areas, sources, and receptors of potential concern, and thus provide a basis for informing pollution reduction strategies and focusing efforts on specific pollutants (diesel particles, acrolein, and formaldehyde), geographic areas (urban centers), and source categories (nonpoint sources). The results heighten concerns about risks from food chain exposures to dioxins and PAHs. Risk estimates were sensitive to variations in methodologies for treating emissions, dispersion, deposition, exposure, and toxicity. © 2011 Society for Risk Analysis.

Potential sources of nitrous acid (HONO) and their impacts on ozone: A WRF-Chem study in a polluted subtropical region

NASA Astrophysics Data System (ADS)

Zhang, Li; Wang, Tao; Zhang, Qiang; Zheng, Junyu; Xu, Zheng; Lv, Mengyao

2016-04-01

Current chemical transport models commonly undersimulate the atmospheric concentration of nitrous acid (HONO), which plays an important role in atmospheric chemistry, due to the lack or inappropriate representations of some sources in the models. In the present study, we parameterized up-to-date HONO sources into a state-of-the-art three-dimensional chemical transport model (Weather Research and Forecasting model coupled with Chemistry: WRF-Chem). These sources included (1) heterogeneous reactions on ground surfaces with the photoenhanced effect on HONO production, (2) photoenhanced reactions on aerosol surfaces, (3) direct vehicle and vessel emissions, (4) potential conversion of NO2 at the ocean surface, and (5) emissions from soil bacteria. The revised WRF-Chem was applied to explore the sources of the high HONO concentrations (0.45-2.71 ppb) observed at a suburban site located within complex land types (with artificial land covers, ocean, and forests) in Hong Kong. With the addition of these sources, the revised model substantially reproduced the observed HONO levels. The heterogeneous conversions of NO2 on ground surfaces dominated HONO sources contributing about 42% to the observed HONO mixing ratios, with emissions from soil bacterial contributing around 29%, followed by the oceanic source (~9%), photochemical formation via NO and OH (~6%), conversion on aerosol surfaces (~3%), and traffic emissions (~2%). The results suggest that HONO sources in suburban areas could be more complex and diverse than those in urban or rural areas and that the bacterial and/or ocean processes need to be considered in HONO production in forested and/or coastal areas. Sensitivity tests showed that the simulated HONO was sensitive to the uptake coefficient of NO2 on the surfaces. Incorporation of the aforementioned HONO sources significantly improved the simulations of ozone, resulting in increases of ground-level ozone concentrations by 6-12% over urban areas in Hong Kong and the Pearl River Delta region. This result highlights the importance of accurately representing HONO sources in simulations of secondary pollutants over polluted regions.

Is forest management a significant source of monoterpenes into the boreal atmosphere?

NASA Astrophysics Data System (ADS)

Haapanala, S.; Hakola, H.; Hellén, H.; Vestenius, M.; Levula, J.; Rinne, J.

2012-04-01

Volatile organic compounds (VOCs) including terpenoids are emitted into the atmosphere from various natural sources. Damaging the plant tissue is known to strongly increase their monoterpene release. We measured the terpenoid emissions caused by timber felling, i.e. those from stumps and logging residue. The emissions from stumps were studied using enclosures and those from the whole felling area using an ecosystem-scale micrometeorological method, disjunct eddy accumulation (DEA). The compounds analyzed were isoprene, monoterpenes and sesquiterpenes. Strong emissions of monoterpenes were measured from both the stumps and from the whole felling area. The emission rate decreased rapidly within a few months after the logging. In addition to fresh logging residue, the results suggest also other strong monoterpene sources may be present in the felling area. These could include pre-existing litter, increased microbial activity and remaining undergrowth. In order to evaluate the possible importance of monoterpenes emitted annually from cut Scots pine forests in Finland, we conducted a rough upscaling calculation. The resulting monoterpene release was approximated to be on the order of 15 kilotonnes per year, which corresponds to about one tenth of the monoterpene release from intact forests in Finland.

An emission processing system for air quality modelling in the Mexico City metropolitan area: Evaluation and comparison of the MOBILE6.2-Mexico and MOVES-Mexico traffic emissions.

PubMed

Guevara, M; Tena, C; Soret, A; Serradell, K; Guzmán, D; Retama, A; Camacho, P; Jaimes-Palomera, M; Mediavilla, A

2017-04-15

This article describes the High-Elective Resolution Modelling Emission System for Mexico (HERMES-Mex) model, an emission processing tool developed to transform the official Mexico City Metropolitan Area (MCMA) emission inventory into hourly, gridded (up to 1km 2 ) and speciated emissions used to drive mesoscale air quality simulations with the Community Multi-scale Air Quality (CMAQ) model. The methods and ancillary information used for the spatial and temporal disaggregation and speciation of the emissions are presented and discussed. The resulting emission system is evaluated, and a case study on CO, NO 2 , O 3 , VOC and PM 2.5 concentrations is conducted to demonstrate its applicability. Moreover, resulting traffic emissions from the Mobile Source Emission Factor Model for Mexico (MOBILE6.2-Mexico) and the MOtor Vehicle Emission Simulator for Mexico (MOVES-Mexico) models are integrated in the tool to assess and compare their performance. NO x and VOC total emissions modelled are reduced by 37% and 26% in the MCMA when replacing MOBILE6.2-Mexico for MOVES-Mexico traffic emissions. In terms of air quality, the system composed by the Weather Research and Forecasting model (WRF) coupled with the HERMES-Mex and CMAQ models properly reproduces the pollutant levels and patterns measured in the MCMA. The system's performance clearly improves in urban stations with a strong influence of traffic sources when applying MOVES-Mexico emissions. Despite reducing estimations of modelled precursor emissions, O 3 peak averages are increased in the MCMA core urban area (up to 30ppb) when using MOVES-Mexico mobile emissions due to its VOC-limited regime, while concentrations in the surrounding suburban/rural areas decrease or increase depending on the meteorological conditions of the day. The results obtained suggest that the HERMES-Mex model can be used to provide model-ready emissions for air quality modelling in the MCMA. Copyright © 2017 Elsevier B.V. All rights reserved.

Differential Absorption Lidar (DIAL) Measurements of Landfill Methane Emissions

NASA Astrophysics Data System (ADS)

Innocenti, Fabrizio; Robinson, Rod; Gardiner, Tom; Finlayson, Andrew; Connor, Andy

2017-04-01

DIFFERENTIAL ABSORPTION LIDAR (DIAL) MEASURMENTS OF LANDFILL METHANE EMISSIONS F. INNOCENTI *, R.A. ROBINSON *, T.D. GARDINER, A. FINLAYSON *, A. CONNOR* * National Physical Laboratory (NPL), Hampton Road, Teddington, Middlesex, TW11 0LW, United Kingdom Methane is one of the most important gaseous hydrocarbon species for both industrial and environmental reasons. Understanding and quantifying methane emissions to atmosphere is an important element of climate change research. Range-resolved infrared Differential Absorption Lidar (DIAL) measurements provide the means to map and quantify a wide range of different methane sources. DIAL is a powerful technique that can be used to track and quantify plumes emitted from area emission sources such as landfill sites, waste water treatment plants and petrochemical plants. By using lidar (light detection and ranging), the DIAL technique is able to make remote range-resolved single-ended measurements of the actual distribution of target gases in the atmosphere, with no disruption to normal site operational activities. DIAL provides 3D mapping of emission concentrations and quantification of emission rates for a wide range of target gases such as methane. The NPL DIAL laser source is operated alternately at two similar wavelengths. One of these, termed the "on-resonant wavelength", is chosen to be at a wavelength which is absorbed by the target species. The other, the "off-resonant wavelength", is chosen to be at a nearby wavelength which is not absorbed significantly by the target species. The two wavelengths are chosen to be close, so that the atmospheric scattering properties are the same for both wavelengths. They are also chosen so that any differential absorption due to other atmospheric species are minimised. Any measured difference in the returned signals is therefore due to absorption by the target gas. In the typical DIAL measurement configuration the mobile DIAL facility is positioned downwind of the area being investigated. The DIAL laser beam is then scanned in a vertical plane and the distribution of the target gas in the measurement plane is mapped. By combining this information with the wind conditions, the technique provides a direct measure of the emission rate of the target gas and its spatial distribution rather than the path-averaged concentration given by most other optical remote sensing methods. This means that localised, high concentration plumes can be discriminated from broad, low concentration plumes, and that emissions from different sources within an area can be spatially separated and independently quantified. As an example, the localised emission from an engine stack or flare can be separated from the diffuse emission from a capped area. Horizontal scans just above the surface can also be performed and they are generally used to identify emission hot-spots. Over the last decade the NPL DIAL system has carried out landfill emission surveys at over thirty sites in the UK, France and the USA measuring the total site and area-specific emissions from e.g. active areas, capped areas and engine stacks. This history of emissions measurements made with DIAL at landfill sites is testament to the maturity of the technique that can be deployed as reference tool by the waste industry. The DIAL data can be used by the site operators to validate emissions estimates and by the regulators to revise and update the emission inventories.

Atmospheric CO2 at Waliguan station in China: Transport climatology, temporal patterns and source-sink region representativeness

NASA Astrophysics Data System (ADS)

Cheng, Siyang; An, Xingqin; Zhou, Lingxi; Tans, Pieter P.; Jacobson, Andy

2017-06-01

In order to explore where the source and sink have the greatest impact on CO2 background concentration at Waliguan (WLG) station, a statistical method is here proposed to calculate the representative source-sink region. The key to this method is to find the best footprint threshold, and the study is carried out in four parts. Firstly, transport climatology, expressed by total monthly footprint, was simulated by FLEXPART on a 7-day time scale. Surface CO2 emissions in Eurasia frequently transported to WLG station. WLG station was mainly influenced by the westerlies in winter and partly controlled by the Southeast Asian monsoon in summer. Secondly, CO2 concentrations, simulated by CT2015, were processed and analyzed through data quality control, screening, fitting and comparing. CO2 concentrations displayed obvious seasonal variation, with the maximum and minimum concentration appearing in April and August, respectively. The correlation of CO2 fitting background concentrations was R2 = 0.91 between simulation and observation. The temporal patterns were mainly correlated with CO2 exchange of biosphere-atmosphere, human activities and air transport. Thirdly, for the monthly CO2 fitting background concentrations from CT2015, a best footprint threshold was found based on correlation analysis and numerical iteration using the data of footprints and emissions. The grid cells where monthly footprints were greater than the best footprint threshold were the best threshold area corresponding to representative source-sink region. The representative source-sink region of maximum CO2 concentration in April was primarily located in Qinghai province, but the minimum CO2 concentration in August was mainly influenced by emissions in a wider region. Finally, we briefly presented the CO2 source-sink characteristics in the best threshold area. Generally, the best threshold area was a carbon sink. The major source and sink were relatively weak owing to less human activities and vegetation types in this high altitude area. CO2 concentrations were more influenced by human activities when air mass passed through many urban areas in summer. Therefore, the combination of footprints and emissions is an effective approach for assessing the source-sink region representativeness of CO2 background concentration.

Characterization of Methane Emission Sources Using Genetic Algorithms and Atmospheric Transport Modeling

NASA Astrophysics Data System (ADS)

Cao, Y.; Cervone, G.; Barkley, Z.; Lauvaux, T.; Deng, A.; Miles, N.; Richardson, S.

2016-12-01

Fugitive methane emission rates for the Marcellus shale area are estimated using a genetic algorithm that finds optimal weights to minimize the error between simulated and observed concentrations. The overall goal is to understand the relative contribution of methane due to Shale gas extraction. Methane sensors were installed on four towers located in northeastern Pennsylvania to measure atmospheric concentrations since May 2015. Inverse Lagrangian dispersion model runs are performed from each of these tower locations for each hour of 2015. Simulated methane concentrations at each of the four towers are computed by multiplying the resulting footprints from the atmospheric simulations by thousands of emission sources grouped into 11 classes. The emission sources were identified using GIS techniques, and include conventional and unconventional wells, different types of compressor stations, pipelines, landfills, farming and wetlands. Initial estimates for each source are calculated based on emission factors from EPA and few regional studies. A genetic algorithm is then used to identify optimal emission rates for the 11 classes of methane emissions and to explore extreme events and spatial and temporal structures in the emissions associated with natural gas activities.

40 CFR 52.1391 - Emission inventories.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) The Governor of the State of Montana submitted the 1990 carbon monoxide base year emission inventories... Governor submitted the 1990 carbon monoxide base year emission inventory for Great Falls on April 23, 1997...-road sources. These 1990 base year carbon monoxide inventories satisfy the nonattainment area...

40 CFR 52.1391 - Emission inventories.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) The Governor of the State of Montana submitted the 1990 carbon monoxide base year emission inventories... Governor submitted the 1990 carbon monoxide base year emission inventory for Great Falls on April 23, 1997...-road sources. These 1990 base year carbon monoxide inventories satisfy the nonattainment area...

40 CFR 52.1391 - Emission inventories.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) The Governor of the State of Montana submitted the 1990 carbon monoxide base year emission inventories... Governor submitted the 1990 carbon monoxide base year emission inventory for Great Falls on April 23, 1997...-road sources. These 1990 base year carbon monoxide inventories satisfy the nonattainment area...

40 CFR 52.1391 - Emission inventories.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) The Governor of the State of Montana submitted the 1990 carbon monoxide base year emission inventories... Governor submitted the 1990 carbon monoxide base year emission inventory for Great Falls on April 23, 1997...-road sources. These 1990 base year carbon monoxide inventories satisfy the nonattainment area...

76 FR 79593 - Approval, and Promulgation of Air Quality Implementation Plans; Ohio; Redesignation of the Ohio...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-22

... sulfur dioxide (SO 2 ) emissions inventories as satisfying the requirement in section 172(c)(3) for a... and quantification of allowable emissions for major new and modified stationary sources in an area, and section 172(c)(5) requires source permits for the construction and operation of new and modified...

Temporal variability in the sources and fluxes of CO2 in a residential area in an evergreen subtropical city

NASA Astrophysics Data System (ADS)

Weissert, L. F.; Salmond, J. A.; Turnbull, J. C.; Schwendenmann, L.

2016-10-01

Measurements of CO2 fluxes in temperate climates have shown that urban areas are a net source of CO2 and that photosynthetic CO2 uptake is generally not sufficient to offset local CO2 emissions. However, little is known about the role of vegetation in cities where biogenic CO2 uptake is not limited to a 2-8 months growing season. This study used the eddy covariance technique to quantify the atmospheric CO2 fluxes over a period of 12 months in a residential area in subtropical Auckland, New Zealand, where the vegetation cover (surface cover fraction: 47%) is dominated by evergreen vegetation. Radiocarbon isotope measurements of CO2 were conducted at three different times of the day (06:00-09:00, 12:00-15:00, 01:00-04:00) for four consecutive weekdays in summer and winter to differentiate anthropogenic sources of CO2 (fossil fuel combustion) from biogenic sources (ecosystem respiration, combustion of biofuel/biomass). The results reveal previously unreported patterns for CO2 fluxes, with no seasonal variability and negative (net uptake) CO2 midday fluxes throughout the year, demonstrating photosynthetic uptake by the evergreen vegetation all year-round. The winter radiocarbon measurements showed that 85% of the CO2 during the morning rush hour was attributed to fossil fuel emissions, when wind was from residential areas. However, for all other time periods radiocarbon measurements showed that fossil fuel combustion was not a large source of CO2, suggesting that biogenic processes likely dominate CO2 fluxes at this residential site. Overall, our findings highlight the importance of vegetation in residential areas to mitigate local CO2 emissions, particularly in cities with a climate that allows evergreen vegetation to maintain high photosynthetic rates over winter. As urban areas grow, urban planners need to consider the role of urban greenspace to mitigate urban CO2 emissions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werth, David; Buckley, Robert

Here, the detectability of emission sources, defined by a low-level of mixing with other sources, was estimated for various locations surrounding the Sea of Japan, including a site within North Korea. A high-resolution meteorological model coupled to a dispersion model was used to simulate plume dynamics for four periods, and two metrics of airborne plume mixing were calculated for each source. While emissions from several known sources in this area tended to blend with others while dispersing downwind, the North Korean plume often remained relatively distinct, thereby making it potentially easier to unambiguously ‘backtrack’ it to its source.

Final Air Toxics Standards for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources Fact Sheet

EPA Pesticide Factsheets

This page contains a December 2007 fact sheet with information regarding the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for Clay Ceramics Manufacturing, Glass Manufacturing, and Secondary Nonferrous Metals Processing Area Sources

Source apportion of atmospheric particulate matter: a joint Eulerian/Lagrangian approach.

PubMed

Riccio, A; Chianese, E; Agrillo, G; Esposito, C; Ferrara, L; Tirimberio, G

2014-12-01

PM2.5 samples were collected during an annual monitoring campaign (January 2012-January 2013) in the urban area of Naples, one of the major cities in Southern Italy. Samples were collected by means of a standard gravimetric sampler (Tecora Echo model) and characterized from a chemical point of view by ion chromatography. As a result, 143 samples together with their ionic composition have been collected. We extend traditional source apportionment techniques, usually based on multivariate factor analysis, interpreting the chemical analysis results within a Lagrangian framework. The Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT) model was used, providing linkages to the source regions in the upwind areas. Results were analyzed in order to quantify the relative weight of different source types/areas. Model results suggested that PM concentrations are strongly affected not only by local emissions but also by transboundary emissions, especially from the Eastern and Northern European countries and African Saharan dust episodes.

QUANTIFICATION OF FUGITIVE REACTIVE ALKENE EMISSIONS FROM PETROCHEMICAL PLANTS WITH PERFLUOROCARBON TRACERS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

SENUM,G.I.; DIETZ,R.N.

2004-06-30

Recent studies demonstrate the impact of fugitive emissions of reactive alkenes on the atmospheric chemistry of the Houston Texas metropolitan area (1). Petrochemical plants located in and around the Houston area emit atmospheric alkenes, such as ethene, propene and 1,3-butadiene. The magnitude of emissions is a major uncertainty in assessing their effects. Even though the petrochemical industry reports that fugitive emissions of alkenes have been reduced to less than 0.1% of daily production, recent measurement data, obtained during the TexAQS 2000 experiment indicates that emissions are perhaps a factor of ten larger than estimated values. Industry figures for fugitive emissionsmore » are based on adding up estimated emission factors for every component in the plant to give a total estimated emission from the entire facility. The dramatic difference between estimated and measured rates indicates either that calculating emission fluxes by summing estimates for individual components is seriously flawed, possibly due to individual components leaking well beyond their estimated tolerances, that not all sources of emissions for a facility are being considered in emissions estimates, or that there are known sources of emissions that are not being reported. This experiment was designed to confirm estimates of reactive alkene emissions derived from analysis of the TexAQS 2000 data by releasing perfluorocarbon tracers (PFTs) at a known flux from a petrochemical plant and sampling both the perfluorocarbon tracer and reactive alkenes downwind using the Piper-Aztec research aircraft operated by Baylor University. PFTs have been extensively used to determine leaks in pipelines, air infiltration in buildings, and to characterize the transport and dispersion of air parcels in the atmosphere. Over 20 years of development by the Tracer Technology Center (TTC) has produced a range of analysis instruments, field samplers and PFT release equipment that have been successfully deployed in a large variety of experiments. PFTs are inert, nontoxic, noncombustible and nonreactive. Up to seven unique PFTs can be simultaneously released, sampled and analyzed and the technology is well suited for determining emission fluxes from large petrochemical facilities. The PFT experiment described here was designed to quantitate alkene emissions from a single petrochemical facility, but such experiments could be applied to other industrial sources or groups of sources in the Houston area.« less

Source apportionment of PM(2.5) in the harbour-industrial area of Brindisi (Italy): identification and estimation of the contribution of in-port ship emissions.

PubMed

Cesari, D; Genga, A; Ielpo, P; Siciliano, M; Mascolo, G; Grasso, F M; Contini, D

2014-11-01

Harbours are important for economic and social development of coastal areas but they also represent an anthropogenic source of emissions often located near urban centres and industrial areas. This increases the difficulties in distinguishing the harbour contribution with respect to other sources. The aim of this work is the characterisation of main sources of PM2.5 acting on the Brindisi harbour-industrial area, trying to pinpoint the contribution of in-port ship emissions to primary and secondary PM2.5. Brindisi is an important port-city of the Adriatic Sea considered a hot-spot for anthropogenic environmental pressures at National level. Measurements were performed collecting PM2.5 samples and characterising the concentrations of 23 chemical species (water soluble organic and inorganic carbon; major ions: SO4(2-), NO3(-), NH4(+), Cl(-), C2O4(2-), Na(+), K(+), Mg(2+), Ca(2+); and elements: Ni, Cu, V, Mn, As, Pb, Cr, Sb, Fe, Al, Zn, and Ti). These species represent, on average, 51.4% of PM2.5 and were used for source apportionment via PMF. The contributions of eight sources were estimated: crustal (16.4±0.9% of PM2.5), aged marine (2.6±0.5%), crustal carbonates (7.7±0.3%), ammonium sulphate (27.3±0.8%), biomass burning-fires (11.7±0.7%), traffic (16.4±1.7 %), industrial (0.4±0.3%) and a mixed source oil combustion-industrial including ship emissions in harbour (15.3±1.3%). The PMF did not separate the in-port ship emission contribution from industrial releases. The correlation of estimated contribution with meteorology showed directionality with an increase of oil combustion and sulphate contribution in the harbour direction with respect to the direction of the urban area and an increase of the V/Ni ratio. This allowed for the use of V as marker of primary ship contribution to PM2.5 (2.8%+/-1.1%). The secondary contribution of oil combustion to non-sea-salt-sulphate, nssSO4(2-), was estimated to be 1.3 μg/m(3) (about 40% of total nssSO4(2-) or 11% of PM2.5). Copyright © 2014 Elsevier B.V. All rights reserved.

Benzene observations and source appointment in a region of oil and natural gas development

NASA Astrophysics Data System (ADS)

Halliday, Hannah Selene

Benzene is a primarily anthropogenic volatile organic compound (VOC) with a small number of well characterized sources. Atmospheric benzene affects human health and welfare, and low level exposure (< 0.5 ppbv) has been connected to measureable increases in cancer rates. Benzene measurements have been increasing in the region of oil and natural gas (O&NG) development located to the north of Denver. High time resolution measurements of VOCs were collected using a proton-transfer-reaction quadrupole mass spectrometry (PTR-QMS) instrument at the Platteville Atmospheric Observatory (PAO) in Colorado to investigate how O&NG development impacts air quality within the Wattenburg Gas Field (WGF) in the Denver-Julesburg Basin. The measurements were carried out in July and August 2014 as part of NASA's DISCOVER-AQ field campaign. The PTR-QMS data were supported by pressurized whole air canister samples and airborne vertical and horizontal surveys of VOCs. Unexpectedly high benzene mixing ratios were observed at PAO at ground level (mean benzene = 0.53 ppbv, maximum benzene = 29.3 ppbv), primarily at night (mean nighttime benzene = 0.73 ppbv). These high benzene levels were associated with southwesterly winds. The airborne measurements indicate that benzene originated from within the WGF, and typical source signatures detected in the canister samples implicate emissions from O&NG activities rather than urban vehicular emissions as primary benzene source. This conclusion is backed by a regional toluene-to-benzene ratio analysis which associated southerly flow with vehicular emissions from the Denver area. Weak benzene-to-CO correlations confirmed that traffic emissions were not responsible for the observed high benzene levels. Previous measurements at the Boulder Atmospheric Observatory (BAO) and our data obtained at PAO allow us to locate the source of benzene enhancements between the two atmospheric observatories. Fugitive emissions of benzene from O&NG operations in the Platteville area are discussed as the most likely causes of enhanced benzene levels at PAO. A limited information source attribution with the PAO dataset was completed using the EPA's positive matrix factorization (PMF) source receptor model. Six VOCs from the PTR-QMS measurement were used along with CO and NO for a total of eight chemical species. Six sources were identified in the PMF analysis: a primarily CO source, an aged vehicle emissions source, a diesel/compressed natural gas emissions source, a fugitive emissions source, and two sources that have the characteristics of a mix of fresh vehicle emissions and condensate fugitive emissions. 70% of the benzene measured at PAO on the PTR-QMS is attributed to fugitive emissions, primarily located to the SW of PAO. Comparing the PMF source attribution to source calculations done with a source array configured from the literature returns a contradictory result, with the expected sources indicting that aged vehicle emissions are the primary benzene source. However, analysis of the contradictory result indicates that the toluene to benzene ratio measured for PAO is much lower than the literature values, suggesting that the O&NG source emissions have a lower ratio of toluene to benzene than anticipated based on studies of other regions. Finally, we propose and investigate an alternative form of the source receptor model using a constrained optimization. Poor results of the proposed method are described with tests on a synthetic testing dataset, and further testing with the observation data from PAO indicate that the proposed method is not able to converge the best global solution to the system.

Avoiding Clean Air Act Enforcement Actions

DTIC Science & Technology

1994-06-01

process or common-source permits (for instance, all boilers or all sources within a defined area on one per- mit); or separate permits for every source of... boilers ; and explosive produc- tion processes. The limitations on NO. emissions may become more stringent if it is determined that these emissions...ISC = Infornmtbon Systems C~r;, INSCOM w; HSC m HhO Sewims Com- rand; FORSCOM - Forces Command; ARNG a Army Natonal Guwd; AMC = Army Maet Command

Mobile measurement of methane emissions from natural gas developments in northeastern British Columbia, Canada

NASA Astrophysics Data System (ADS)

Atherton, Emmaline; Risk, David; Fougère, Chelsea; Lavoie, Martin; Marshall, Alex; Werring, John; Williams, James P.; Minions, Christina

2017-10-01

North American leaders recently committed to reducing methane emissions from the oil and gas sector, but information on current emissions from upstream oil and gas developments in Canada are lacking. This study examined the occurrence of methane plumes in an area of unconventional natural gas development in northwestern Canada. In August to September 2015 we completed almost 8000 km of vehicle-based survey campaigns on public roads dissecting oil and gas infrastructure, such as well pads and processing facilities. We surveyed six routes 3-6 times each, which brought us past over 1600 unique well pads and facilities managed by more than 50 different operators. To attribute on-road plumes to oil- and gas-related sources we used gas signatures of residual excess concentrations (anomalies above background) less than 500 m downwind from potential oil and gas emission sources. All results represent emissions greater than our minimum detection limit of 0.59 g s-1 at our average detection distance (319 m). Unlike many other oil and gas developments in the US for which methane measurements have been reported recently, the methane concentrations we measured were close to normal atmospheric levels, except inside natural gas plumes. Roughly 47 % of active wells emitted methane-rich plumes above our minimum detection limit. Multiple sites that pre-date the recent unconventional natural gas development were found to be emitting, and we observed that the majority of these older wells were associated with emissions on all survey repeats. We also observed emissions from gas processing facilities that were highly repeatable. Emission patterns in this area were best explained by infrastructure age and type. Extrapolating our results across all oil and gas infrastructure in the Montney area, we estimate that the emission sources we located (emitting at a rate > 0.59 g s-1) contribute more than 111 800 t of methane annually to the atmosphere. This value exceeds reported bottom-up estimates of 78 000 t of methane for all oil and gas sector sources in British Columbia. Current bottom-up methods for estimating methane emissions do not normally calculate the fraction of emitting oil and gas infrastructure with thorough on-ground measurements. However, this study demonstrates that mobile surveys could provide a more accurate representation of the number of emission sources in an oil and gas development. This study presents the first mobile collection of methane emissions from oil and gas infrastructure in British Columbia, and these results can be used to inform policy development in an era of methane emission reduction efforts.

Source apportionment vs. emission inventories of non-methane hydrocarbons (NMHC) in an urban area of the Middle East: local and global perspectives

NASA Astrophysics Data System (ADS)

Salameh, Thérèse; Sauvage, Stéphane; Afif, Charbel; Borbon, Agnès; Locoge, Nadine

2016-03-01

We applied the positive matrix factorization model to two large data sets collected during two intensive measurement campaigns (summer 2011 and winter 2012) at a sub-urban site in Beirut, Lebanon, in order to identify NMHC (non-methane hydrocarbons) sources and quantify their contribution to ambient levels. Six factors were identified in winter and five factors in summer. PMF-resolved source profiles were consistent with source profiles established by near-field measurements. The major sources were traffic-related emissions (combustion and gasoline evaporation) in winter and in summer accounting for 51 and 74 wt %, respectively, in agreement with the national emission inventory. The gasoline evaporation related to traffic source had a significant contribution regardless of the season (22 wt % in winter and 30 wt % in summer). The NMHC emissions from road transport are estimated from observations and PMF results, and compared to local and global emission inventories. The PMF analysis finds reasonable differences on emission rates, of 20-39 % higher than the national road transport inventory. However, global inventories (ACCMIP, EDGAR, MACCity) underestimate the emissions up to a factor of 10 for the transportation sector. When combining emission inventory to our results, there is strong evidence that control measures in Lebanon should be targeted on mitigating the NMHC emissions from the traffic-related sources. From a global perspective, an assessment of VOC (volatile organic compounds) anthropogenic emission inventories for the Middle East region as a whole seems necessary as these emissions could be much higher than expected at least from the road transport sector.

Research on the Emission Inventory of Major Air Pollutants in 2012 for the Sichuan City Cluster in China

NASA Astrophysics Data System (ADS)

Qian, J.; He, Q.

2014-12-01

This paper developed a high resolution emission inventory of major pollutants in city cluster of Sichuan Basin, one of the most polluted regions in China. The city cluster included five cities, which were Chengdu, Deyang, Mianyang, Meishan and Ziyang. Pollution source census and field measurements were conducted for the major emission sources such as the industry sources, on-road mobile sources, catering sources and the dust sources. The inventory results showed that in the year of 2012, the emission of SO2、NOX、CO、PM10、PM2.5、VOCs and NH3 in the region were 143.5、251.9、1659.9、299.3、163.5、464.1 and 995kt respectively. Chengdu, the provincial capital city, had the largest emission load of every pollutant among the cities. The industry sources, including power plants, fuel combustion facilities and non-combustion processes were the largest emission sources for SO2、NOX and CO, contributing to 84%, 46.5%, 35% of total SO2, NOX and CO emissions. On-road mobile sources accounted for 46.5%, 33%, 16% of the total NOx, CO, PM2.5 emissions and 28% of the anthropogenic VOCs emission. Dust and industry sources contributed to 42% and 23% of the PM10 emission with the dust sources also as the largest source of PM2.5, contributing to 27%. Anthropogenic and biogenic sources took 75% and 25% of the total VOCs emission while 36% of anthropogenic VOCs emission was owing to solvent use. Livestock contributed to 62% of NH3 emissions, followed by nitrogen fertilizer application whose contribution was 23%. Based on the developed emission inventory and local meteorological data, the regional air quality modeling system WRF-CMAQ was applied to simulate the status of PM2.5 pollution in a regional scale. The results showed that high PM2.5 concentration was distributed over the urban area of Chengdu and Deyang. On-road mobile sources and dust sources were two major contributors to the PM2.5 pollution in Chengdu, both had an contribution ratio of 27%. In Deyang, Mianyang, Meishan and Ziyang, industry sources had a relatively high contribution ratio to the PM2.5 pollution, accounting for about 35%, 33%, 38% and 24% respectively.

Relative importance of atmospheric and riverine mercury sources to the northern Gulf of Mexico.

PubMed

Rice, Glenn E; Senn, David B; Shine, James P

2009-01-15

A box model was developed to quantify the major sources and dominant fates of inorganic mercury (Hg) in the Mississippi River-influenced area of the northern Gulf of Mexico (nGOM). Riverine (75%) and direct atmospheric deposition (25%) deliver 9.7 t Hg y(-1) to this productive fishery; most (80%) accumulates in bottom sediments where it can be methylated and enter foodwebs. Although riverine inputs dominate atmospheric deposition, 75% of the riverine sediment-associated Hg accumulates in only approximately 8% of the study area. Atmospheric deposition can explain most of the Hg accumulating in sediments of the remaining area. Considering the differences in temporal responsiveness of riverine (centuries) and atmospheric (years) Hg inputs to anthropogenic emissions changes, the spatial limits of the riverine Hg source andthe potential dominance of atmospheric deposition over large areas could have implications for the timing of benefits from policies reducing anthropogenic Hg emissions.

Emission Measurements of Open Area Combustion Sources with an Unmanned Aerial System

EPA Science Inventory

miniaturized sensor/sampler system (“Kolibri”) on a six-motor, unmanned aerial system (UAS) was used to quantify emissions from open burning of obsolete military propellants. The UAS afforded the ability to sample plume emissions at altitude and from a safe distance ...

AGRICULTURAL AMMONIA EMISSIONS AND AMMONIUM DEPOSITION IN THE SOUTHEAST UNITED STATES

EPA Science Inventory

The paper gives an estimate of county-scale annual ammonia (NH3) emissions in eight Southeastern States for the year 1997, using emission factors and activity data for all domestic livestock and fertilizer sources. A geographical distribution of the data yields local areas (1000...

The new open Flexible Emission Inventory for Greece and the Greater Athens Area (FEI-GREGAA): Account of pollutant sources and their importance from 2006 to 2012

NASA Astrophysics Data System (ADS)

Fameli, Kyriaki-Maria; Assimakopoulos, Vasiliki D.

2016-07-01

Photochemical and particulate pollution problems persist in Athens as they do in various European cities, despite measures taken. Although, for many cities, organized and updated pollutant emissions databases exist, as well as infrastructure for the support of policy implementation, this is not the case for Greece and Athens. So far abstract efforts to create inventories from temporal and spatial annual low resolution data have not lead to the creation of a useful database. The objective of this study was to construct an emission inventory in order to examine the emission trends in Greece and the Greater Athens Area for the period 2006-2012 on a spatial scale of 6 × 6 km2 and 2 × 2 km2, respectively and on a temporal scale of 1 h. Emissions were calculated from stationary combustion sources, transportation (road, navigation and aviation), agriculture and industry obtained from official national and European sources. Moreover, new emission factors were calculated for road transport and aviation. The final database named F.E.I. - GREGAA (Flexible Emission Inventory for GREece and the GAA) is open-structured so as to receive data updates, new pollutants, various emission scenarios and/or different emission factors and be transformed for any grid spacing. Its main purpose is to be used in applications with photochemical models to contribute to the investigation on the type of sources and activities that lead to the configuration of air quality. Results showed a decreasing trend in CO, NOx and VOCs-NMVOCs emissions and an increasing trend from 2011 onwards in PM10 emissions. Road transport and small combustion contribute most to CO emissions, road transport and navigation to NOx and small combustion and industries to PM10. The onset of the economic crisis can be seen from the reduction of emissions from industry and the increase of biomass burning for heating purposes.

Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions. Part II: source contribution assessment using the Chemical Mass Balance (CMB) model.

PubMed

Badol, Caroline; Locoge, Nadine; Galloo, Jean-Claude

2008-01-25

In Part I of this study (Badol C, Locoge N, Leonardis T, Gallo JC. Using a source-receptor approach to characterise VOC behaviour in a French urban area influenced by industrial emissions, Part I: Study area description, data set acquisition and qualitative data analysis of the data set. Sci Total Environ 2007; submitted as companion manuscript.) the study area, acquisition of the one-year data set and qualitative analysis of the data set have been described. In Part II a source profile has been established for each activity present in the study area: 6 profiles (urban heating, solvent use, natural gas leakage, biogenic emissions, gasoline evaporation and vehicle exhaust) have been extracted from literature to characterise urban sources, 7 industrial profiles have been established via canister sampling around industrial plants (hydrocarbon cracking, oil refinery, hydrocarbon storage, lubricant storage, lubricant refinery, surface treatment and metallurgy). The CMB model is briefly described and its implementation is discussed through the selection of source profiles and fitting species. Main results of CMB modellings for the Dunkerque area are presented. (1) The daily evolution of source contributions for the urban wind sector shows that the vehicle exhaust source contribution varies between 40 and 55% and its relative increase at traffic rush hours is hardly perceptible. (2) The relative contribution of vehicle exhaust varies from 55% in winter down to 30% in summer. This decrease is due to the increase of the relative contribution of hydrocarbon storage source reaching up to 20% in summer. (3) The evolution of source contributions with wind directions has confirmed that in urban wind sectors the contribution of vehicle exhaust dominate with around 45-55%. For the other wind sectors that include some industrial plants, the contribution of industrial sources is around 60% and could reach 80% for the sector 280-310 degrees , which corresponds to the most dense industrial area. (4) The pollution in Dunkerque has been globally characterised taking into account the frequency of wind directions and contributions of sources in each wind direction for the whole year. It has been concluded that contribution of industrial sources is below 20% whereas vehicle exhaust contribution is superior to 40%.

Quantification of Methane Source Locations and Emissions in AN Urban Setting

NASA Astrophysics Data System (ADS)

Crosson, E.; Richardson, S.; Tan, S. M.; Whetstone, J.; Bova, T.; Prasad, K. R.; Davis, K. J.; Phillips, N. G.; Turnbull, J. C.; Shepson, P. B.; Cambaliza, M. L.

2011-12-01

The regulation of methane emissions from urban sources such as landfills and waste-water treatment facilities is currently a highly debated topic in the US and in Europe. This interest is fueled, in part, by recent measurements indicating that urban emissions are a significant source of Methane (CH4) and in fact may be substantially higher than current inventory estimates(1). As a result, developing methods for locating and quantifying emissions from urban methane sources is of great interest to industries such as landfill and wastewater treatment facility owners, watchdog groups, and the governmental agencies seeking to evaluate or enforce regulations. In an attempt to identify major methane source locations and emissions in Boston, Indianapolis, and the Bay Area, systematic measurements of CH4 concentrations and meteorology data were made at street level using a vehicle mounted cavity ringdown analyzer. A number of discrete sources were detected at concentration levels in excess of 15 times background levels. Using Gaussian plume models as well as tomographic techniques, methane source locations and emission rates will be presented. In addition, flux chamber measurements of discrete sources such as those found in natural gas leaks will also be presented. (1) Wunch, D., P.O. Wennberg, G.C. Toon, G. Keppel-Aleks, and Y.G. Yavin, Emissions of Greenhouse Gases from a North American Megacity, Geophysical Research Letters, Vol. 36, L15810, doi:10.1029/2009GL)39825, 2009.

Comparison of WindTrax and flux-gradient technique in determining PM10 emission rates from a beef cattle feedlot

USDA-ARS?s Scientific Manuscript database

Several emission estimation methods can be used to determine emission fluxes from ground-level area sources, including open-lot beef cattle feedlots. This research determined PM10 emission fluxes from a commercial cattle feedlot in Kansas using WindTrax, a backward Lagrangian stochastic-based atmosp...

THE CHALLENGE OF QUALITY ASSURANCE FOR EMISSION FLUX MEASUREMENTS OF LARGE AREA SOURCES BY OPTICAL REMOTE SENSING

EPA Science Inventory

The paper examines the quality assurance challenges associated with open path Fourier transform infrared (OPFTIR) measurements of large area pollution sources with plume reconstruction by computed tomography (CT) and how each challenge may be met. Traditionally, pollutant concent...

40 CFR 63.11588 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other Requirements and Information § 63.11588 What definitions apply to this subpart? Chemical... by the paints and allied products area source rule (40 CFR part 63, subpart CCCCCCC). Chemical...

40 CFR 63.11588 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other Requirements and Information § 63.11588 What definitions apply to this subpart? Chemical... by the paints and allied products area source rule (40 CFR part 63, subpart CCCCCCC). Chemical...

40 CFR 63.11588 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other Requirements and Information § 63.11588 What definitions apply to this subpart? Chemical... by the paints and allied products area source rule (40 CFR part 63, subpart CCCCCCC). Chemical...

40 CFR 63.11400 - Am I subject to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) National Emission Standards for Hazardous Air Pollutants for Carbon Black Production Area Sources... if you own or operate a carbon black production facility that is an area source of hazardous air... units, maintenance wastewater, and equipment components that contain or contact HAP that are associated...

Urban atmospheric pollution in the Eastern Mediterranean : lessons from the TRANSEMED initiative

NASA Astrophysics Data System (ADS)

Borbon, Agnes; Salameh, Therese; Gaimoz, Cecile; Sauvage, Stephane; Locoge, Nadine; Oztürk, Fatma; Cetin, Banu; Keles, Melek; Afif, Charbel

2016-04-01

The East Mediterranean Basin (EMB) is a highly sensitive environment under considerable pressures. Future decadal projections point to the EMB as a possible hot spot of poor air quality and predict a continual and gradual warming in the region, much stronger than other regions. The increase and accumulation of anthropogenic emissions of gaseous and particulate pollutants from surrounding urban areas, are suspected as one of the key compounding factors of those environmental impacts. The quantification of emission distribution is a challenge, and even more in cities of the EMB where local emission data are sparse. While some highly resolved inventories have been developed at the regional scale in the EMB area for Beirut and Istanbul, their uncertainties are unknown. The paucity of observations in this region, especially for VOCs and PM composition, is a strong limitation to the achievement of evaluated and accurate emission inventories. As part of the TRANSEMED initiative (https://charmex.lsce.ipsl.fr/index.php/sister-projects/transemed.html), one of our objectives is to develop a systematic source-receptor methodology for emission inventory evaluation. We combine existing and newly collected observations and complementary source-receptor approaches (ie., urban enhancement emission ratios, multivariate models like PMF) in representative areas of the EMB: Beirut (Lebanon), Istanbul (Turkey), Cairo (Egypt) and, more recently, Athens (Greece). Over the past five years a very detailed database of ambient and near-source observations has been built-up especially regarding the composition of gaseous organic carbon. Results show (i) the extremely high levels of pollution for organics, (ii) the dominance of traffic emissions on VOC concentration levels, (iii) the relative poor spatial variability of speciated hydrocarbon traffic emissions regardless of the region, and (iv) the high uncertainty on global emission inventories when compared to observations. For the latter, and from a global perspective, the relative importance of Eastern Mediterranean emissions is suspected to be largely underestimated compared to other regions worldwide: they could be as significant for VOC and NOx as the ones of Europe and North America or even higher for PM2.5. This work was supported by the ENVIMED and ChArMEx programmes within MISTRALS. The author would like to thank Thierry Leonardis for his technical support. References: Borbon et al., Composition of gaseous organic carbon during ECOCEM in Beirut, Lebanon: new observational constraints for VOC/OVOC anthropogenic emission evaluation in the Middle East region. In preparation for ACP. Salameh et al., Source apportionment vs. emission inventories of non-methane hydrocarbons (NMHC) in an urban area of the Middle East: local and global perspectives, in revision for ACP, 2016. http://www.atmos-chem-phys-discuss.net/15/26795/2015/acpd-15-26795-2015.html Salameh et al., Exploring the seasonal NMHC distribution in an urban area of the Middle East during ECOCEM campaigns: very high loadings dominated by local emissions and dynamics. Environ. Chem. 12 (3), 316 - 328. doi : 10.1071/EN14154, 2015. Salameh et al., Speciation of Non-Methane Hydrocarbons (NMHC) from anthropogenic sources in Beirut, Lebanon, Environ Sci. Pollut. Res., 21, 10867 - 10877. DOI: 10.1007/s11356-014-2978-5, 2014.

A multi-sensor burned area algorithm for crop residue burning in northwestern India: validation and sources of error

NASA Astrophysics Data System (ADS)

Liu, T.; Marlier, M. E.; Karambelas, A. N.; Jain, M.; DeFries, R. S.

2017-12-01

A leading source of outdoor emissions in northwestern India comes from crop residue burning after the annual monsoon (kharif) and winter (rabi) crop harvests. Agricultural burned area, from which agricultural fire emissions are often derived, can be poorly quantified due to the mismatch between moderate-resolution satellite sensors and the relatively small size and short burn period of the fires. Many previous studies use the Global Fire Emissions Database (GFED), which is based on the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area product MCD64A1, as an outdoor fires emissions dataset. Correction factors with MODIS active fire detections have previously attempted to account for small fires. We present a new burned area classification algorithm that leverages more frequent MODIS observations (500 m x 500 m) with higher spatial resolution Landsat (30 m x 30 m) observations. Our approach is based on two-tailed Normalized Burn Ratio (NBR) thresholds, abbreviated as ModL2T NBR, and results in an estimated 104 ± 55% higher burned area than GFEDv4.1s (version 4, MCD64A1 + small fires correction) in northwestern India during the 2003-2014 winter (October to November) burning seasons. Regional transport of winter fire emissions affect approximately 63 million people downwind. The general increase in burned area (+37% from 2003-2007 to 2008-2014) over the study period also correlates with increased mechanization (+58% in combine harvester usage from 2001-2002 to 2011-2012). Further, we find strong correlation between ModL2T NBR-derived burned area and results of an independent survey (r = 0.68) and previous studies (r = 0.92). Sources of error arise from small median landholding sizes (1-3 ha), heterogeneous spatial distribution of two dominant burning practices (partial and whole field), coarse spatio-temporal satellite resolution, cloud and haze cover, and limited Landsat scene availability. The burned area estimates of this study can be used to build a new agricultural fire emissions inventory to re-evaluate the contributions of winter agricultural fires to rural and urban air quality degradation.

Parse, simulation, and prediction of NOx emission across the Midwestern United States

NASA Astrophysics Data System (ADS)

Fang, H.; Michalski, G. M.; Spak, S.

2017-12-01

Accurately constraining N emissions in space and time has been a challenge for atmospheric scientists. It has been suggested that 15N isotopes may be a way of tracking N emission sources across various spatial and temporal scales. However, the complexity of multiple N sources that can quickly change in intensity has made this a difficult problem. We have used a SMOKE emission model to parse NOx emission across the Midwestern United States for a one-year simulation. An isotope mass balance methods was used to assign 15N values to road, non-road, point, and area sources. The SMOKE emissions and isotope mass balance were then combined to predict the 15N of NOx emissions (Figure 1). This ^15N of NOx emissions model was then incorporated into CMAQ to assess the role of transport and chemistry would impact the 15N value of NOx due to mixing and removal processes. The predicted 15N value of NOx was compared to those in recent measurements of NOx and atmospheric nitrate.

Linking seasonal surface water dynamics with methane emissions and export from small, forested wetlands

NASA Astrophysics Data System (ADS)

Hondula, K. L.; Palmer, M.

2017-12-01

One of the biggest uncertainties about global methane sources and sinks is attributed to uncertainties regarding wetland area and its dynamics. This is exacerbated by confusion over the role of small, shallow water bodies like Delmarva bay wetlands that could be categorized as both wetlands and ponds. These small inland water bodies are often poorly quantified due to their size, closed forest canopies, and inter- and intra-annual variability in surface water extent. We are studying wetland-rich areas on the Delmarva Peninsula in the U.S. mid-Atlantic to address this uncertainty at the scale of individual wetland ecosystems (<1000 m2). We present data linking measurements of hydrologic regime and methane gas fluxes in Delmarva bay wetlands to explore how water level, wetland storage capacity, and water residence time influence the magnitude, source area, and fate of wetland methane emissions. We measured air-water and soil-air gas fluxes using transects of chamber measurements spanning from wetland center to upland, in order to quantify the areal extent of the methane emissions source area throughout seasonal changes in surface water inundation (water level 0 to > 1m depth). We estimated the size and temporal variability of the methane emissions source area by combining these measurements with daily estimates of the extent of surface water inundation derived from water level monitoring and a high-resolution digital elevation model. This knowledge is critical for informing land use decisions (e.g. restoring wetlands specifically for climate mitigation), the jurisdiction of environmental policies in the US, and for resolving major outstanding discrepancies in our understanding of the global methane budget.

Temporal variation and source identification of black carbon at Lin'an and Longfengshan regional background stations in China

NASA Astrophysics Data System (ADS)

Cheng, Siyang; Wang, Yaqiang; An, Xingqin

2017-12-01

Black carbon (BC) is a component of fine particulate matter (PM2.5), associated with climate, weather, air quality, and people's health. However, studies on temporal variation of atmospheric BC concentration at background stations in China and its source area identification are lacking. In this paper, we use 2-yr BC observations from two background stations, Lin'an (LAN) and Longfengshan (LFS), to perform the investigation. The results show that the mean diurnal variation of BC has two significant peaks at LAN while different characteristics are found in the BC variation at LFS, which are probably caused by the difference in emission source contributions. Seasonal variation of monthly BC shows double peaks at LAN but a single peak at LFS. The annual mean concentrations of BC at LAN and LFS decrease by 1.63 and 0.26 μg m-3 from 2009 to 2010, respectively. The annual background concentration of BC at LAN is twice higher than that at LFS. The major source of the LAN BC is industrial emission while the source of the LFS BC is residential emission. Based on transport climatology on a 7-day timescale, LAN and LFS stations are sensitive to surface emissions respectively in belt or approximately circular area, which are dominated by summer monsoon or colder land air flows in Northwest China. In addition, we statistically analyze the BC source regions by using BC observation and FLEXible PARTicle dispersion model (FLEXPART) simulation. In summer, the source regions of BC are distributed in the northwest and south of LAN and the southwest of LFS. Low BC concentration is closely related to air mass from the sea. In winter, the source regions of BC are concentrated in the west and south of LAN and the northeast of the threshold area of s tot at LFS. The cold air mass in the northwest plays an important role in the purification of atmospheric BC. On a yearly scale, sources of BC are approximately from five provinces in the northwest/southeast of LAN and the west of LFS. These findings are helpful in reducing BC emission and controlling air pollution.

77 FR 20575 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Forest County...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-05

... redesignated area must determine by an analysis whether their emissions will have an adverse impact on those... of the MOA allows for restricting the requirements normally associated with Class I areas as these... demonstration that the emissions from the proposed new major source or major modification would have an adverse...

Guidance for creating annual on-road mobile source emission inventories for PM2.5 nonattainment areas for use in SIPs and conformity.

DOT National Transportation Integrated Search

2005-08-01

The purpose of this document is to provide areas that are nonattainment or maintenance for the annual PM2.5 national ambient air quality standard (standard) with guidance on developing annual PM2.5 on-road motor vehicle emissions estimates to m...

Air quality modeling of selected aromatic and non-aromatic air toxics in the Houston urban and industrial airshed

NASA Astrophysics Data System (ADS)

Coarfa, Violeta Florentina

2007-12-01

Air toxics, also called hazardous air pollutants (HAPs), pose a serious threat to human health and the environment. Their study is important in the Houston area, where point sources, mostly located along the Ship Channel, mobile and area sources contribute to large emissions of such toxic pollutants. Previous studies carried out in this area found dangerous levels of different HAPs in the atmosphere. This thesis presents several studies that were performed for the aromatic and non-aromatic air toxics in the HGA. For these studies we developed several tools: (1) a refined chemical mechanism, which explicitly represents 18 aromatic air toxics that were lumped under two model species by the previous version, based on their reactivity with the hydroxyl radical; (2) an engineering version of an existing air toxics photochemical model that enables us to perform much faster long-term simulations compared to the original model, that leads to a 8--9 times improvement in the running time across different computing platforms; (3) a combined emission inventory based on the available emission databases. Using the developed tools, we quantified the mobile source impact on a few selected air toxics, and analyzed the temporal and spatial variation of selected aromatic and non-aromatic air toxics in a few regions within the Houston area; these regions were characterized by different emissions and environmental conditions.

40 CFR Table 1 to Subpart Gggggg... - Applicability of General Provisions to Primary Zinc Production Area Sources

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Applicability of General Provisions to Primary Zinc Production Area Sources 1 Table 1 to Subpart GGGGGG of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIE...

40 CFR Table 1 to Subpart Gggggg... - Applicability of General Provisions to Primary Zinc Production Area Sources

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Applicability of General Provisions to Primary Zinc Production Area Sources 1 Table 1 to Subpart GGGGGG of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIE...

40 CFR Table 1 to Subpart Gggggg... - Applicability of General Provisions to Primary Zinc Production Area Sources

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Applicability of General Provisions to Primary Zinc Production Area Sources 1 Table 1 to Subpart GGGGGG of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIE...

A 2009 Mobile Source Carbon Dioxide Emissions Inventory for the University of Central Florida.

PubMed

Clifford, Johanna M; Cooper, C David

2012-09-01

A mobile source carbon dioxide (CO2) emissions inventory for the University of Central Florida (UCF) has been completed. Fora large urban university, more than 50% of the CO2 emissions can come from mobile sources, and the vast majority of mobile source emissions come from on-road sources: personal vehicles and campus shuttles carrying students, faculty, staff and administrators to and from the university as well as on university business trips. In addition to emissions from on-road vehicles, emissions from airplane-based business travel are significant, along with emissions from nonroad equipment such as lawnmowers, leaf blowers, and small maintenance vehicles utilized on campus. UCF has recently become one of the largest universities in the nation (with over 58,000 students enrolled in the fall 2011 semester) and emits a substantial amount of CO2 in the Central Florida area. For this inventory, students, faculty, staff and administrators were first surveyed to determine their commuting distances and frequencies. Information was also gathered on vehicle type and age distribution of the personal vehicles of students, faculty, administrators, and staff as well as their bus, car-pool, and alternate transportation usage. The latest US. Environmental Protection Agency (EPA)-approved mobile source emissions model, Motor Vehicle Emissions Simulator (MOVES2010a), was used to calculate the emissions from on-road vehicles, and UCF fleet gasoline consumption records were used to calculate the emissions from nonroad equipment and from on-campus UCF fleet vehicles. The results of this UCF mobile source emissions inventory were compared with those for another large U.S. university. With the growing awareness of global climate change, a number of colleges/universities and other organizations are completing greenhouse gas emission inventories. Assumptions often are made in order to calculate mobile source emissions, but without field data or valid reasoning, the accuracy of those assumptions may be questioned. This paper presents a method that involves a survey, the use of the MOVES model, and emission factors to produce a mobile source emissions inventory. The results show that UCF mobile source CO2 emissions are larger than most other universities, and make up about 2% of all the mobile source emissions in Orange County, Florida.

Wet deposition of mercury at a New York state rural site: Concentrations, fluxes, and source areas

NASA Astrophysics Data System (ADS)

Lai, Soon-onn; Holsen, Thomas M.; Hopke, Philip K.; Liu, Peng

Event-based mercury (Hg) precipitation samples were collected with a modified MIC-B sampler between September 2003 and April 2005 at Potsdam, NY to investigate Hg in wet deposition and identify potential source areas using the potential source contribution function (PCSF) and residence time weighted concentration (RTWC) models. The volume-weighted mean (VWM) concentration and wet deposition flux were 5.5ngL-1 and 7.6μgm-2 during the study period, and 5.5ngL-1 and 5.9μgm-2 in 2004, respectively, and show seasonal trends with larger values in the spring and summer. The PSCF model results matched known source areas based on an emission inventory better than did the RTWC results based on the spatial correlation index. Both modeling results identified large Hg source areas that contain a number of coal-fired power plants located in the Upper Ohio River Valley and in southeastern Michigan, as well as in Quebec and Ontario where there are metal production facilities, waste incinerators and paper mills. Emissions from the Atlantic Ocean were also determined to be a potential source.

Fluxes of Greenhouse Gases from the Baltimore-Washington Area: Results from WINTER 2015 Aircraft Observations

NASA Astrophysics Data System (ADS)

Dickerson, R. R.; Ren, X.; Shepson, P. B.; Salmon, O. E.; Brown, S. S.; Thornton, J. A.; Whetstone, J. R.; Salawitch, R. J.; Sahu, S.; Hall, D.; Grimes, C.; Wong, T. M.

2015-12-01

Urban areas are responsible for a major component of the anthropogenic greenhouse gas (GHG) emissions. Quantification of urban GHG fluxes is important for establishing scientifically sound and cost-effective policies for mitigating GHGs. Discrepancies between observations and model simulations of GHGs suggest uncharacterized sources in urban environments. In this work, we analyze and quantify fluxes of CO2, CH4, CO (and other trace species) from the Baltimore-Washington area based on the mass balance approach using the two-aircraft observations conducted in February-March 2015. Estimated fluxes from this area were 110,000±20,000 moles s-1 for CO2, 700±330 moles s-1 for CH4, and 535±188 moles s-1 for CO. This implies that methane is responsible for ~20% of the climate forcing from these cities. Point sources of CO2 from four regional power plants and one point source of CH4 from a landfill were identified and the emissions from these point sources were quantified based on the aircraft observation and compared to the emission inventory data. Methane fluxes from the Washington area were larger than from the Baltimore area, indicating a larger leakage rate in the Washington area. The ethane-to-methane ratios, with a mean of 3.3%, in the limited canister samples collected during the flights indicate that natural gas leaks and the upwind oil and natural gas operations are responsible for a substantial fraction of the CH4 flux. These observations will be compared to models using Ensemble Kalman Filter Assimilation techniques.

40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet the...

40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet the...

40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet the...

40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet the...

40 CFR Table 1 of Subpart Aaaaaaa... - Emission Limits for Asphalt Processing (Refining) Operations

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Emission Limits for Asphalt Processing... Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and Information... of Part 63—Emission Limits for Asphalt Processing (Refining) Operations For * * * You must meet the...

40 CFR 51.114 - Emissions data and projections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... emissions from point and area sources. Lead requirements are specified in § 51.117. The inventory must be... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Emissions data and projections. 51.114 Section 51.114 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 51.114 - Emissions data and projections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... emissions from point and area sources. Lead requirements are specified in § 51.117. The inventory must be... 40 Protection of Environment 2 2014-07-01 2014-07-01 false Emissions data and projections. 51.114 Section 51.114 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR Table 1 to Subpart Ssssss... - Emission Limits

Code of Federal Regulations, 2012 CFR

2012-07-01

... SSSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63, Subpt. SSSSSS, Table 1 Table 1 to Subpart SSSSSS of Part 63—Emission Limits As required in § 63.11451, you must...

40 CFR Table 1 to Subpart Ssssss... - Emission Limits

Code of Federal Regulations, 2011 CFR

2011-07-01

... SSSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63, Subpt. SSSSSS, Table 1 Table 1 to Subpart SSSSSS of Part 63—Emission Limits As required in § 63.11451, you must...

40 CFR Table 1 to Subpart Ssssss... - Emission Limits

Code of Federal Regulations, 2013 CFR

2013-07-01

... SSSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63, Subpt. SSSSSS, Table 1 Table 1 to Subpart SSSSSS of Part 63—Emission Limits As required in § 63.11451, you must...

40 CFR Table 1 to Subpart Ssssss... - Emission Limits

Code of Federal Regulations, 2014 CFR

2014-07-01

... SSSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63, Subpt. SSSSSS, Table 1 Table 1 to Subpart SSSSSS of Part 63—Emission Limits As required in § 63.11451, you must...

40 CFR Table 1 to Subpart Ssssss... - Emission Limits

Code of Federal Regulations, 2010 CFR

2010-07-01

... SSSSSS of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area Sources Pt. 63, Subpt. SSSSSS, Table 1 Table 1 to Subpart SSSSSS of Part 63—Emission Limits As required in § 63.11451, you must...

PM RESEARCH

EPA Science Inventory

Activity Area (F03): PM Implementation NRMRL conducts research to improve the techniques used to quantify PM and PM precursor emissions from stationary, mobile, and fugitive sources and investigates the performance and cost of innovative control technology systems. The emission...

Dynamism of household carbon emissions (HCEs) from rural and urban regions of northern and southern China.

PubMed

Maraseni, Tek Narayan; Qu, Jiansheng; Yue, Bian; Zeng, Jingjing; Maroulis, Jerry

2016-10-01

China contributes 23 % of global carbon emissions, of which 26 % originate from the household sector. Due to vast variations in both climatic conditions and the affordability and accessibility of fuels, household carbon emissions (HCEs) differ significantly across China. This study compares HCEs (per person) from urban and rural regions in northern China with their counterparts in southern China. Annual macroeconomic data for the study period 2005 to 2012 were obtained from Chinese government sources, whereas the direct HCEs for different types of fossil fuels were obtained using the IPCC reference approach, and indirect HCEs were calculated by input-output analysis. Results suggest that HCEs from urban areas are higher than those from rural areas. Regardless of the regions, there is a similarity in per person HCEs in urban areas, but the rural areas of northern China had significantly higher HCEs than those from southern China. The reasons for the similarity between urban areas and differences between rural areas and the percentage share of direct and indirect HCEs from different sources are discussed. Similarly, the reasons and solutions to why decarbonising policies are working in urban areas but not in rural areas are discussed.

FIELD EVALUATION OF A METHOD FOR ESTIMATING GASEOUS FLUXES FROM AREA SOURCES USING OPEN-PATH FTIR

EPA Science Inventory

The paper gives preliminary results from a field evaluation of a new approach for quantifying gaseous fugitive emissions of area air pollution sources. The approach combines path-integrated concentration data acquired with any path-integrated optical remote sensing (PI-ORS) ...

FIELD EVALUATION OF A METHOD FOR ESTIMATING GASEOUS FLUXES FROM AREA SOURCES USING OPEN-PATH FOURIER TRANSFORM INFRARED

EPA Science Inventory

The paper describes preliminary results from a field experiment designed to evaluate a new approach to quantifying gaseous fugitive emissions from area air pollution sources. The new approach combines path-integrated concentration data acquired with any path-integrated optical re...

DEVELOPMENT OF THE MODEL OF GALACTIC INTERSTELLAR EMISSION FOR STANDARD POINT-SOURCE ANALYSIS OF FERMI LARGE AREA TELESCOPE DATA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acero, F.; Ballet, J.; Ackermann, M.

2016-04-01

Most of the celestial γ rays detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point-source and extended-source studies rely on the modeling of this diffuse emission for accurate characterization. Here, we describe the development of the Galactic Interstellar Emission Model (GIEM), which is the standard adopted by the LAT Collaboration and is publicly available. This model is based on a linear combination of maps for interstellar gas column density in Galactocentric annuli and for the inverse-Compton emission producedmore » in the Galaxy. In the GIEM, we also include large-scale structures like Loop I and the Fermi bubbles. The measured gas emissivity spectra confirm that the cosmic-ray proton density decreases with Galactocentric distance beyond 5 kpc from the Galactic Center. The measurements also suggest a softening of the proton spectrum with Galactocentric distance. We observe that the Fermi bubbles have boundaries with a shape similar to a catenary at latitudes below 20° and we observe an enhanced emission toward their base extending in the north and south Galactic directions and located within ∼4° of the Galactic Center.« less

Development of the Model of Galactic Interstellar Emission for Standard Point-Source Analysis of Fermi Large Area Telescope Data

NASA Technical Reports Server (NTRS)

Acero, F.; Ackermann, M.; Ajello, M.; Albert, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Brandt, T. J.;

High resolution of anthropogenic atmospheric emissions of 12 heavy metals in the three biggest metropolitan areas, China

NASA Astrophysics Data System (ADS)

Tian, H.; Zhu, C.

2015-12-01

Atmospheric emissions of typical toxic heavy metals from anthropogenic sources have received worldwide concerns due to their adverse effects on human health and the ecosystem. An integrated inventory of anthropogenic emissions of twelve HMs (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu and Zn) in the three biggest metropolitan areas, including Beijing-Tianjin-Hebei (BTH) region, Yangtze River Delta (YRD) region and Pearl River Delta (PRD) region, are developed for 1980-2012 by combining with detailed activity data and inter-annual dynamic emission factors which are determined by S-shaped curves on account of technology progress, economic development, and emission control. The results indicate total emissions of twelve HMs in the three metropolitan regions have increased from 5448.8 tons in 1980 to 19054.9 tons in 2012, with an annual average growth rate of about 4.0%. Due to significant difference in industrial structures and energy consumption compositions, remarkable distinctions can be observed with respect to source contributions of total HM emissions from above three metropolitan areas. Specifically, the ferrous metal smelting sector, coal combustion by industrial boilers and coal combustion by power plants are found to be the primary source of total HM emissions in the BTH region (about 34.2%), YRD region (about 28.2%) and PRD region (about 24.3%), respectively. Furthermore, we allocate the annual emissions of these heavy metals in 2012 at a high spatial resolution of 9 km × 9 km grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). The peak of HM emissions are mainly distributed over the grid cells of Beijing, Tianjin, Tangshan, Shijiazhuang, Handan and Baoding in the BTH region; Shanghai, Suzhou, Wuxi, Nanjing, Hangzhou, Ningbo in the YRD region; Guangzhou, Shenzhen, Dongguan, Foshan in the PYD region, respectively. Additionally, monthly emission profiles are established in order to further identify the temporal emission characteristics of HMs. Key words: heavy metals (HMs), emission inventory, time-varying dynamic emission factor, temporal and spatial characteristics, Beijing-Tianjin-Hebei (BTH) region, Yangtze River Delta (YRD) region, Pearl River Delta (PRD) region, China

Identifying and characterizing major emission point sources as a basis for geospatial distribution of mercury emissions inventories

NASA Astrophysics Data System (ADS)

Steenhuisen, Frits; Wilson, Simon J.

2015-07-01

Mercury is a global pollutant that poses threats to ecosystem and human health. Due to its global transport, mercury contamination is found in regions of the Earth that are remote from major emissions areas, including the Polar regions. Global anthropogenic emission inventories identify important sectors and industries responsible for emissions at a national level; however, to be useful for air transport modelling, more precise information on the locations of emission is required. This paper describes the methodology applied, and the results of work that was conducted to assign anthropogenic mercury emissions to point sources as part of geospatial mapping of the 2010 global anthropogenic mercury emissions inventory prepared by AMAP/UNEP. Major point-source emission sectors addressed in this work account for about 850 tonnes of the emissions included in the 2010 inventory. This work allocated more than 90% of these emissions to some 4600 identified point source locations, including significantly more point source locations in Africa, Asia, Australia and South America than had been identified during previous work to geospatially-distribute the 2005 global inventory. The results demonstrate the utility and the limitations of using existing, mainly public domain resources to accomplish this work. Assumptions necessary to make use of selected online resources are discussed, as are artefacts that can arise when these assumptions are applied to assign (national-sector) emissions estimates to point sources in various countries and regions. Notwithstanding the limitations of the available information, the value of this procedure over alternative methods commonly used to geo-spatially distribute emissions, such as use of 'proxy' datasets to represent emissions patterns, is illustrated. Improvements in information that would facilitate greater use of these methods in future work to assign emissions to point-sources are discussed. These include improvements to both national (geo-referenced) emission inventories and also to other resources that can be employed when such national inventories are lacking.

Highlighting Uncertainty and Recommendations for Improvement of Black Carbon Biomass Fuel-Based Emission Inventories in the Indo-Gangetic Plain Region.

PubMed

Soneja, Sutyajeet I; Tielsch, James M; Khatry, Subarna K; Curriero, Frank C; Breysse, Patrick N

2016-03-01

Black carbon (BC) is a major contributor to hydrological cycle change and glacial retreat within the Indo-Gangetic Plain (IGP) and surrounding region. However, significant variability exists for estimates of BC regional concentration. Existing inventories within the IGP suffer from limited representation of rural sources, reliance on idealized point source estimates (e.g., utilization of emission factors or fuel-use estimates for cooking along with demographic information), and difficulty in distinguishing sources. Inventory development utilizes two approaches, termed top down and bottom up, which rely on various sources including transport models, emission factors, and remote sensing applications. Large discrepancies exist for BC source attribution throughout the IGP depending on the approach utilized. Cooking with biomass fuels, a major contributor to BC production has great source apportionment variability. Areas requiring attention tied to research of cookstove and biomass fuel use that have been recognized to improve emission inventory estimates include emission factors, particulate matter speciation, and better quantification of regional/economic sectors. However, limited attention has been given towards understanding ambient small-scale spatial variation of BC between cooking and non-cooking periods in low-resource environments. Understanding the indoor to outdoor relationship of BC emissions due to cooking at a local level is a top priority to improve emission inventories as many health and climate applications rely upon utilization of accurate emission inventories.

Development of a Flight Instrument for in situ Measurements of Ethane and Methane

NASA Astrophysics Data System (ADS)

Wilkerson, J. P.; Sayres, D. S.; Anderson, J. G.

2015-12-01

Methane emissions data for natural gas and oil fields have high uncertainty. Better quantifying these emissions is crucial to establish an accurate methane budget for the United States. One obstacle is that these emissions often occur in areas near livestock facilities where biogenic methane abounds. Measuring ethane, which has no biogenic source, along with methane can tease these sources apart. However, ethane is typically measured by taking whole-air samples. This tactic has lower spatial resolution than making in situ measurements and requires the measurer to anticipate the location of emission plumes. This leaves unexpected plumes uncharacterized. Using Re-injection Mirror Integrated Cavity Output Spectroscopy (RIM-ICOS), we can measure both methane and ethane in flight, allowing us to establish more accurate fugitive emissions data that can more readily distinguish between different sources of this greenhouse gas.

Estimation of the emission factors of PAHs by traffic with the model of atmospheric dispersion and deposition from heavy traffic road.

PubMed

Ozaki, N; Tokumitsu, H; Kojima, K; Kindaichi, T

2007-01-01

In order to consider the total atmospheric loadings of the PAHs (polycyclic aromatic hydrocarbons) from traffic activities, the emission factors of PAHs were estimated and from the obtained emission factors and vehicle transportation statistics, total atmospheric loadings were integrated and the loadings into the water body were estimated on a regional scale. The atmospheric concentration of PAHs was measured at the roadside of a road with heavy traffic in the Hiroshima area in Japan. The samplings were conducted in summer and winter. Atmospheric particulate matters (fine particle, 0.6-7 microm; coarse particle, over 7 microm) and their PAH concentration were measured. Also, four major emission sources (gasoline and diesel vehicle emissions, tire and asphalt debris) were assumed for vehicle transportation activities, the chemical mass balance method was applied and the source partitioning at the roadside was estimated. Furthermore, the dispersion of atmospheric particles from the vehicles was modelled and the emission factors of the sources were determined by the comparison to the chemical mass balance results. Based on emission factors derived from the modelling, an atmospheric dispersion model of nationwide scale (National Institute of Advanced Industrial Science and Technology - Atmospheric Dispersion Model for Exposure and Risk assessment) was applied, and the atmospheric concentration and loading to the ground were calculated for the Hiroshima Bay watershed area.

Estimation of Phosphorus Emissions in the Upper Iguazu Basin (brazil) Using GIS and the More Model

NASA Astrophysics Data System (ADS)

Acosta Porras, E. A.; Kishi, R. T.; Fuchs, S.; Hilgert, S.

2016-06-01

Pollution emissions into the drainage basin have direct impact on surface water quality. These emissions result from human activities that turn into pollution loads when they reach the water bodies, as point or diffuse sources. Their pollution potential depends on the characteristics and quantity of the transported materials. The estimation of pollution loads can assist decision-making in basin management. Knowledge about the potential pollution sources allows for a prioritization of pollution control policies to achieve the desired water quality. Consequently, it helps avoiding problems such as eutrophication of water bodies. The focus of the research described in this study is related to phosphorus emissions into river basins. The study area is the upper Iguazu basin that lies in the northeast region of the State of Paraná, Brazil, covering about 2,965 km2 and around 4 million inhabitants live concentrated on just 16% of its area. The MoRE (Modeling of Regionalized Emissions) model was used to estimate phosphorus emissions. MoRE is a model that uses empirical approaches to model processes in analytical units, capable of using spatially distributed parameters, covering both, emissions from point sources as well as non-point sources. In order to model the processes, the basin was divided into 152 analytical units with an average size of 20 km2. Available data was organized in a GIS environment. Using e.g. layers of precipitation, the Digital Terrain Model from a 1:10000 scale map as well as soils and land cover, which were derived from remote sensing imagery. Further data is used, such as point pollution discharges and statistical socio-economic data. The model shows that one of the main pollution sources in the upper Iguazu basin is the domestic sewage that enters the river as point source (effluents of treatment stations) and/or as diffuse pollution, caused by failures of sanitary sewer systems or clandestine sewer discharges, accounting for about 56% of the emissions. Second significant shares of emissions come from direct runoff or groundwater, being responsible for 32% of the total emissions. Finally, agricultural erosion and industry pathways represent 12% of emissions. This study shows that MoRE is capable of producing valid emission calculation on a relatively reduced input data basis.

Monitoring of PM10 and PM2.5 around primary particulate anthropogenic emission sources

NASA Astrophysics Data System (ADS)

Querol, Xavier; Alastuey, Andrés; Rodriguez, Sergio; Plana, Felicià; Mantilla, Enrique; Ruiz, Carmen R.

Investigations on the monitoring of ambient air levels of atmospheric particulates were developed around a large source of primary anthropogenic particulate emissions: the industrial ceramic area in the province of Castelló (Eastern Spain). Although these primary particulate emissions have a coarse grain-size distribution, the atmospheric transport dominated by the breeze circulation accounts for a grain-size segregation, which results in ambient air particles occurring mainly in the 2.5-10 μm range. The chemical composition of the ceramic particulate emissions is very similar to the crustal end-member but the use of high Al, Ti and Fe as tracer elements as well as a peculiar grain-size distribution in the insoluble major phases allow us to identify the ceramic input in the bulk particulate matter. PM2.5 instead of PM10 monitoring may avoid the interference of crustal particles without a major reduction in the secondary anthropogenic load, with the exception of nitrate. However, a methodology based in PM2.5 measurement alone is not adequate for monitoring the impact of primary particulate emissions (such as ceramic emissions) on air quality, since the major ambient air particles derived from these emissions are mainly in the range of 2.5-10 μm. Consequently, in areas characterised by major secondary particulate emissions, PM2.5 monitoring should detect anthropogenic particulate pollutants without crustal particulate interference, whereas PM10 measurements should be used in areas with major primary anthropogenic particulate emissions.

Evolution of air pollution source contributions over one decade, derived by PM10 and PM2.5 source apportionment in two metropolitan urban areas in Greece

NASA Astrophysics Data System (ADS)

Diapouli, E.; Manousakas, M.; Vratolis, S.; Vasilatou, V.; Maggos, Th; Saraga, D.; Grigoratos, Th; Argyropoulos, G.; Voutsa, D.; Samara, C.; Eleftheriadis, K.

2017-09-01

Metropolitan Urban areas in Greece have been known to suffer from poor air quality, due to variety of emission sources, topography and climatic conditions favouring the accumulation of pollution. While a number of control measures have been implemented since the 1990s, resulting in reductions of atmospheric pollution and changes in emission source contributions, the financial crisis which started in 2009 has significantly altered this picture. The present study is the first effort to assess the contribution of emission sources to PM10 and PM2.5 concentration levels and their long-term variability (over 5-10 years), in the two largest metropolitan urban areas in Greece (Athens and Thessaloniki). Intensive measurement campaigns were conducted during 2011-2012 at suburban, urban background and urban traffic sites in these two cities. In addition, available datasets from previous measurements in Athens and Thessaloniki were used in order to assess the long-term variability of concentrations and sources. Chemical composition analysis of the 2011-2012 samples showed that carbonaceous matter was the most abundant component for both PM size fractions. Significant increase of carbonaceous particle concentrations and of OC/EC ratio during the cold period, especially in the residential urban background sites, pointed towards domestic heating and more particularly wood (biomass) burning as a significant source. PMF analysis further supported this finding. Biomass burning was the largest contributing source at the two urban background sites (with mean contributions for the two size fractions in the range of 24-46%). Secondary aerosol formation (sulphate, nitrate & organics) was also a major contributing source for both size fractions at the suburban and urban background sites. At the urban traffic site, vehicular traffic (exhaust and non-exhaust emissions) was the source with the highest contributions, accounting for 44% of PM10 and 37% of PM2.5, respectively. The long-term variability of emission sources in the two cities (over 5-10 years), assessed through a harmonized application of the PMF technique on recent and past year data, clearly demonstrates the effective reduction in emissions during the last decade due to control measures and technological development; however, it also reflects the effects of the financial crisis in Greece during these years, which has led to decreased economic activities and the adoption of more polluting practices by the local population in an effort to reduce living costs.

Quantifying methane emission from fugitive sources by combining tracer release and downwind measurements - a sensitivity analysis based on multiple field surveys.

PubMed

Mønster, Jacob G; Samuelsson, Jerker; Kjeldsen, Peter; Rella, Chris W; Scheutz, Charlotte

2014-08-01

Using a dual species methane/acetylene instrument based on cavity ring down spectroscopy (CRDS), the dynamic plume tracer dispersion method for quantifying the emission rate of methane was successfully tested in four measurement campaigns: (1) controlled methane and trace gas release with different trace gas configurations, (2) landfill with unknown emission source locations, (3) landfill with closely located emission sources, and (4) comparing with an Fourier transform infrared spectroscopy (FTIR) instrument using multiple trace gasses for source separation. The new real-time, high precision instrument can measure methane plumes more than 1.2 km away from small sources (about 5 kg h(-1)) in urban areas with a measurement frequency allowing plume crossing at normal driving speed. The method can be used for quantification of total methane emissions from diffuse area sources down to 1 kg per hour and can be used to quantify individual sources with the right choice of wind direction and road distance. The placement of the trace gas is important for obtaining correct quantification and uncertainty of up to 36% can be incurred when the trace gas is not co-located with the methane source. Measurements made at greater distances are less sensitive to errors in trace gas placement and model calculations showed an uncertainty of less than 5% in both urban and open-country for placing the trace gas 100 m from the source, when measurements were done more than 3 km away. Using the ratio of the integrated plume concentrations of tracer gas and methane gives the most reliable results for measurements at various distances to the source, compared to the ratio of the highest concentration in the plume, the direct concentration ratio and using a Gaussian plume model. Under suitable weather and road conditions, the CRDS system can quantify the emission from different sources located close to each other using only one kind of trace gas due to the high time resolution, while the FTIR system can measure multiple trace gasses but with a lower time resolution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vehicle NOx emission plume isotopic signatures: Spatial variability across the eastern United States

NASA Astrophysics Data System (ADS)

Miller, David J.; Wojtal, Paul K.; Clark, Sydney C.; Hastings, Meredith G.

2017-04-01

On-road vehicle nitrogen oxide (NOx) sources currently dominate the U.S. anthropogenic emission budgets, yet vehicle NOx emissions have uncertain contributions to oxidized nitrogen (N) deposition patterns. Isotopic signatures serve as a potentially valuable observational tool to trace source contributions to NOx chemistry and N deposition, yet in situ emission signatures are underconstrained. We characterize the spatiotemporal variability of vehicle NOx emission isotopic signatures (δ15N-NOx) representative of U.S. vehicle fleet-integrated emission plumes. A novel combination of on-road mobile and stationary urban measurements is performed using a field and laboratory-verified technique for actively capturing NOx in solution to quantify δ15N-NOx at hourly resolution. On-road δ15N-NOx upwind of Providence, RI, ranged from -7 to -3‰. Simultaneous urban background δ15N-NOx observations showed comparable range and variations with on-road measurements, suggesting that vehicles dominate NOx emissions in the Providence area. On-road spatial δ15N-NOx variations of -9 to -2‰ were observed under various driving conditions in six urban metropolitan areas and rural interstate highways during summer and autumn in the U.S. Northeast and Midwest. Although isotopic signatures were insensitive to on-road driving mode variations, statistically significant correlations were found between δ15N-NOx and NOx emission factor extremes associated with heavy diesel emitter contributions. Overall, these results constrain an isotopic signature of fleet-integrated roadway NOx emission plumes, which have important implications for distinguishing vehicle NOx from other sources and tracking emission contributions to NOx chemistry and N deposition.

Human impacts on river water quality- comparative research in the catchment areas of the Tone River and the Mur River-

NASA Astrophysics Data System (ADS)

Kogure, K.

2013-12-01

Human activities in river basin affect river water quality as water discharges into river with pollutant after we use it. By detecting pollutants source, pathway, and influential factor of human activities, it will be possible to consider proper river basin management. In this study, material flow analysis was done first and then nutrient emission modeling by MONERIS was conducted. So as to clarify land use contribution and climate condition, comparison of Japanese and European river basin area has been made. The model MONERIS (MOdelling Nutrient Emissions in RIver Systems; Behrendt et al., 2000) was applied to estimate the nutrient emissions in the Danube river basin by point sources and various diffuse pathways. Work for the Mur River Basin in Austria was already carried out by the Institute of Water Quality, Resources and Waste Management at the Vienna University of Technology. This study treats data collection, modelling for the Tone River in Japan, and comparative analysis for these two river basins. The estimation of the nutrient emissions was carried out for 11 different sub catchment areas covering the Tone River Basin for the time period 2000 to 2006. TN emissions into the Tone river basin were 51 kt/y. 67% was via ground water and dominant for all sub catchments. Urban area was also important emission pathway. Human effect is observed in urban structure and agricultural activity. Water supply and sewer system make urban water cycle with pipeline structure. Excess evapotranspiration in arable land is also influential in water cycle. As share of arable land is 37% and there provides agricultural products, it is thought that N emission from agricultural activity is main pollution source. Assumption case of 10% N surplus was simulated and the result was 99% identical to the actual. Even though N surplus reduction does not show drastic impact on N emission, it is of importance to reduce excess of fertilization and to encourage effective agricultural activity. Population rate of waste water treatment is 67 % in the total catchment area. Assumption case of 100% WWT was simulated and the result suggests that connection to public sewer system with WWTP is effective potential measure. TN emission in the Tone is higher than it in the Mur. Emission per capita is almost same level for both basin areas. Though the personal pollution stresses same as European basin area, the basin has huge population and activities to support their daily life. Agricultural activity and urban structure have great impacts on N emission and on the river water quality. Possible remedy for river pollution is construction of sewer system with waste water treatment. Agricultural activity is potential betterment factor. Comparison of Mur, Tone and assumption cases

Sensitivity of surface characteristics on the simulation of wind-blown-dust source in North America

NASA Astrophysics Data System (ADS)

Park, S. H.; Gong, S. L.; Gong, W.; Makar, P. A.; Moran, M. D.; Stroud, C. A.; Zhang, J.

Recently, a wind-blown-dust-emission module has been built based on a state-of-the-art wind erosion theory and evaluated in a regional air-quality model to simulate a North American dust storm episode in April 2001 (see Park, S.H., Gong, S.L., Zhao, T.L., Vet, R.J., Bouchet, V.S., Gong, W., Makar, P.A., Moran, M.D., Stroud, C., Zhang, J. 2007. Simulation of entrainment and transport of dust particles within North America in April 2001 ("Red Dust episode"). J. Geophys. Res. 112, D20209, doi:10.1029/2007JD008443). A satisfactorily detailed assessment of that module, however, was not possible because of a lack of information on some module inputs, especially soil moisture content. In this paper, the wind-blown-dust emission was evaluated for two additional dust storms using improved soil moisture inputs. The surface characteristics of the wind-blown-dust source areas in southwestern North America were also investigated, focusing on their implications for wind-blown-dust emissions. The improved soil moisture inputs enabled the sensitivity of other important surface characteristics, the soil grain size distribution and the land-cover, to dust emission to be investigated with more confidence. Simulations of the two 2003 dust storm episodes suggested that wind-blown-dust emissions from the desert areas in southwestern North America are dominated by emissions from dry playas covered with accumulated alluvial deposits whose particle size is much smaller than usual desert sands. As well, the source areas in the northwestern Texas region were indicated to be not desert but rather agricultural lands that were "activated" as a wind-blown-dust sources after harvest. This finding calls for revisions to the current wind-blown-dust-emission module, in which "desert" is designated to be the only land-cover category that can emit wind-blown dust.

Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

NASA Astrophysics Data System (ADS)

Zavala, M.; Lei, W.; Molina, M. J.; Molina, L. T.

2009-01-01

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City

NASA Astrophysics Data System (ADS)

Zavala, M.; Lei, W. F.; Molina, M. J.; Molina, L. T.

2008-08-01

The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.

Gaseous emissions from outdoor concrete yards used by livestock

NASA Astrophysics Data System (ADS)

Misselbrook, T. H.; Webb, J.; Chadwick, D. R.; Ellis, S.; Pain, B. F.

Measurements of ammonia (NH 3), nitrous oxide (N 2O) and methane (CH 4) were made from 11 outdoor concrete yards used by livestock. Measurements of NH 3 emission were made using the equilibrium concentration technique while closed chambers were used to measure N 2O and CH 4 emissions. Outdoor yards used by livestock proved to be an important source of NH 3 emission. Greatest emission rates were measured from dairy cow feeding yards, with a mean of 690 mg NH 3-N m -2 h -1. Smaller emission rates were measured from sheep handling areas, dairy cow collecting yards, beef feeding yards and a pig loading area, with respective mean emission rates of 440, 280, 220 and 140 mg NH 3-N m -2 h -1. Emission rates of N 2O and CH 4 were much smaller and for CH 4, in particular, emission rates were influenced greatly by the presence or absence of dung on the measurement area.

Mobile laboratory measurements of atmospheric emissions from agriculture, oil, and natural gas activities in northeastern Colorado

NASA Astrophysics Data System (ADS)

Eilerman, S. J.; Peischl, J.; Neuman, J. A.; Ryerson, T. B.; Wild, R. J.; Perring, A. E.; Brown, S. S.; Aikin, K. C.; Holloway, M.; Roberts, O.

2014-12-01

Atmospheric emissions from agriculture are important to air quality and climate, yet their representation in inventories is incomplete. Increased fertilizer use has lead to increased emissions of nitrogen compounds, which can adversely affect ecosystems and contribute to the formation of fine particulates. Furthermore, extraction and processing of oil and natural gas continues to expand throughout northeastern Colorado; emissions from these operations require ongoing measurement and characterization. This presentation summarizes initial data and analysis from a summer 2014 campaign to study emissions of nitrogen compounds, methane, and other species in northeastern Colorado using a new mobile laboratory. A van was instrumented to measure NH3, N2O, NOx, NOy, CH4, CO, CO2, O3, and bioaerosols with high time resolution. By sampling in close proximity to a variety of emissions sources, the mobile laboratory facilitated accurate source identification and quantification of emissions ratios. Measurements were obtained near agricultural sites, natural gas and oil operations, and other point sources. Additionally, extensive measurements were obtained downwind from urban areas and along roadways. The relationship between ammonia and other trace gases is used to characterize sources and constrain emissions inventories.

Source apportionment of volatile organic compounds measured near a cold heavy oil production area

NASA Astrophysics Data System (ADS)

Aklilu, Yayne-abeba; Cho, Sunny; Zhang, Qianyu; Taylor, Emily

2018-07-01

This study investigated sources of volatile organic compounds (VOCs) observed during periods of elevated hydrocarbon concentrations adjacent to a cold heavy oil extraction area in Alberta, Canada. Elevated total hydrocarbon (THC) concentrations were observed during the early morning hours and were associated with meteorological conditions indicative of gravitational drainage flows. THC concentrations were higher during the colder months, an occurrence likely promoted by a lower mixing height. On the other hand, other VOCs had higher concentrations in the summer; this is likely due to increased evaporation and atmospheric chemistry during the summer months. Of all investigated VOC compounds, alkanes contributed the greatest in all seasons. A source apportionment method, positive matrix factorization (PMF), was used to identify the potential contribution of various sources to the observed VOC concentrations. A total of five factors were apportioned including Benzene/Hexane, Oil Evaporative, Toluene/Xylene, Acetone and Assorted Local/Regional Air Masses. Three of the five factors (i.e., Benzene/Hexane, Oil Evaporative, and Toluene/Xylene), formed 27% of the reconstructed and unassigned concentration and are likely associated with emissions from heavy oil extraction. The three factors associated with emissions were comparable to the available emission inventory for the area. Potential sources include solution gas venting, combustion exhaust and fugitive emissions from extraction process additives. The remaining two factors (i.e., Acetone and Assorted Local/Regional Air Mass), comprised 49% of the reconstructed and unassigned concentration and contain key VOCs associated with atmospheric chemistry or the local/regional air mass such as acetone, carbonyl sulphide, Freon-11 and butane.

A small, lightweight multipollutant sensor system for ground-mobile and aerial emission sampling from open area sources

NASA Astrophysics Data System (ADS)

Zhou, Xiaochi; Aurell, Johanna; Mitchell, William; Tabor, Dennis; Gullett, Brian

2017-04-01

Characterizing highly dynamic, transient, and vertically lofted emissions from open area sources poses unique measurement challenges. This study developed and applied a multipollutant sensor and time-integrated sampler system for use on mobile applications such as vehicles, tethered balloons (aerostats) and unmanned aerial vehicles (UAVs) to determine emission factors. The system is particularly applicable to open area sources, such as forest fires, due to its light weight (3.5 kg), compact size (6.75 L), and internal power supply. The sensor system, termed ;Kolibri;, consists of sensors measuring CO2 and CO, and samplers for particulate matter (PM) and volatile organic compounds (VOCs). The Kolibri is controlled by a microcontroller which can record and transfer data in real time through a radio module. Selection of the sensors was based on laboratory testing for accuracy, response delay and recovery, cross-sensitivity, and precision. The Kolibri was compared against rack-mounted continuous emissions monitoring system (CEMs) and another mobile sampling instrument (the ;Flyer;) that has been used in over ten open area pollutant sampling events. Our results showed that the time series of CO, CO2, and PM2.5 concentrations measured by the Kolibri agreed well with those from the CEMs and the Flyer, with a laboratory-tested percentage error of 4.9%, 3%, and 5.8%, respectively. The VOC emission factors obtained using the Kolibri were consistent with existing literature values that relate concentration to modified combustion efficiency. The potential effect of rotor downwash on particle sampling was investigated in an indoor laboratory and the preliminary results suggested that its influence is minimal. Field application of the Kolibri sampling open detonation plumes indicated that the CO and CO2 sensors responded dynamically and their concentrations co-varied with emission transients. The Kolibri system can be applied to various challenging open area scenarios such as fires, lagoons, flares, and landfills.

Agricultural peat lands; towards a greenhouse gas sink - a synthesis of a Dutch landscape study

NASA Astrophysics Data System (ADS)

Schrier-Uijl, A. P.; Kroon, P. S.; Hendriks, D. M. D.; Hensen, A.; Van Huissteden, J. C.; Leffelaar, P. A.; Berendse, F.; Veenendaal, E. M.

2013-06-01

It is generally known that managed, drained peatlands act as carbon sources. In this study we examined how mitigation through the reduction of management and through rewetting may affect the greenhouse gas (GHG) emission and the carbon balance of intensively managed, drained, agricultural peatlands. Carbon and GHG balances were determined for three peatlands in the western part of the Netherlands from 2005 to 2008 by considering spatial and temporal variability of emissions (CO2, CH4 and N2O). One area (Oukoop) is an intensively managed grass-on-peatland, including a dairy farm, with the ground water level at an average annual depth of 0.55 m below the soil surface. The second area (Stein) is an extensively managed grass-on-peatland, formerly intensively managed, with a dynamic ground water level at an average annual depth of 0.45 m below the soil surface. The third area is an (since 1998) rewetted former agricultural peatland (Horstermeer), close to Oukoop and Stein, with the average annual ground water level at a depth of 0.2 m below the soil surface. During the measurement campaigns we found that both agriculturally managed sites acted as carbon and GHG sources but the rewetted agricultural peatland acted as a carbon and GHG sink. The terrestrial GHG source strength was 1.4 kg CO2-eq m-2 yr-1 for the intensively managed area and 1.0 kg CO2-eq m-2 yr-1 for the extensively managed area; the unmanaged area acted as a GHG sink of 0.7 kg CO2-eq m-2 yr-1. Water bodies contributed significantly to the terrestrial GHG balance because of a high release of CH4 and the loss of DOC only played a minor role. Adding the farm-based CO2 and CH4 emissions increased the source strength for the managed sites to 2.7 kg CO2-eq m-2 yr-1 for Oukoop and 2.1 kg CO2-eq m-2 yr-1 for Stein. Shifting from intensively managed to extensively managed grass-on-peat reduced GHG emissions mainly because N2O emission and farm-based CH4 emissions decreased. Overall, this study suggests that managed peatlands are large sources of GHG and carbon, but, if appropriate measures are taken they can be turned back into GHG and carbon sinks within 15 yr of abandonment and rewetting.

Large area, surface discharge pumped, vacuum ultraviolet light source

DOEpatents

Sze, Robert C.; Quigley, Gerard P.

1996-01-01

Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source. A contamination-free VUV light source having a 225 cm.sup.2 emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm.sup.2 at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing.

Source apportionment of VOCs and the contribution to photochemical ozone formation during summer in the typical industrial area in the Yangtze River Delta, China

NASA Astrophysics Data System (ADS)

Shao, Ping; An, Junlin; Xin, Jinyuan; Wu, Fangkun; Wang, Junxiu; Ji, Dongsheng; Wang, Yuesi

2016-07-01

Volatile organic compounds (VOCs) were continuously observated in a northern suburb of Nanjing, a typical industrial area in the Yangtze River Delta, in a summer observation period from 15th May to 31st August 2013. The average concentration of total VOCs was (34.40 ± 25.20) ppbv, including alkanes (14.98 ± 12.72) ppbv, alkenes (7.35 ± 5.93) ppbv, aromatics (9.06 ± 6.64) ppbv and alkynes (3.02 ± 2.01) ppbv, respectively. Source apportionment via Positive Matrix Factorization was conducted, and six major sources of VOCs were identified. The industry-related sources, including industrial emissions and industrial solvent usage, occupied the highest proportion, accounting for about 51.26% of the VOCs. Vehicular emissions occupied the second highest proportion, accounting for about 34.08%. The rest accounted for about 14.66%, including vegetation emission and liquefied petroleum gas/natural gas usage. Contributions of VOCs to photochemical O3 formation were evaluated by the application of a detailed chemical mechanism model (NCAR MM). Alkenes were the dominant contributors to the O3 photochemical production, followed by aromatics and alkanes. Alkynes had a very small impact on photochemical O3 formation. Based on the outcomes of the source apportionment, a sensitivity analysis of relative O3 reduction efficiency (RORE), under different source removal regimes such as using the reduction of VOCs from 10% to 100% as input, was conducted. The RORE was the highest (~ 20%-40%) when the VOCs from solvent-related sources decreased by 40%. The highest RORE values for vegetation emissions, industrial emissions, vehicle exhaust, and LPG/NG usage were presented in the scenarios of 50%, 80%, 40% and 40%, respectively.

Characterization of Industrial Emission Sources and Photochemistry in Houston, Texas

NASA Astrophysics Data System (ADS)

Washenfelder, R. A.; Atlas, E. L.; Degouw, J.; Flocke, F. M.; Fried, A.; Frost, G. J.; Holloway, J.; Richter, D.; Ryerson, T. B.; Schauffler, S.; Trainer, M.; Walega, J.; Warneke, C.; Weibring, P.; Zheng, W.

2009-12-01

The Houston-Galveston urban area contains a number of large industrial petrochemical emission sources that produce volatile organic compounds and nitrogen oxides. These co-located emissions result in rapid and efficient ozone production downwind. Unlike a single large power plant, the industrial complexes consist of numerous sources that can be difficult to quantify in emission inventories. During September - October 2006, the NOAA WP-3 aircraft conducted research flights as part of the second Texas Air Quality Study (TexAQS II). We examine measurements of NOx, SO2, and speciated hydrocarbons from the Houston Ship Channel, which contains a dense concentration of industrial petrochemical sources, and isolated petrochemical facilities. These measurements are used to derive source emission estimates, which are then compared to available emission inventories. We find that high hydrocarbon emissions are typical for the Houston Ship Channel and isolated petrochemical facilities. Ethene and propene are found to be major contributors to ozone formation. Ratios of C2H4 / NOx and C3H6 / NOx exceed emission inventory values by factors of 10 - 50. These findings are consistent with the first TexAQS study in 2000. We examine trends in C2H4 / NOx and C3H6 / NOx ratios between 2000 and 2006, and determine that day-to-day variability and within-plume variability exceeds any long-term reduction in ethene and propene emissions for the isolated petrochemical sources. We additionally examine downwind photochemical products formed by these alkenes.

Impact of maritime transport on particulate matter concentrations and chemical compositions in four port-cities of the Adriatic/Ionian area: an overview of the results of POSEIDON project

NASA Astrophysics Data System (ADS)

Contini, Daniele; Gambaro, Andrea; Argiriou, Athanasios; Alebic-Juretic, Ana; Barbaro, Elena; Cesari, Daniela; Dimopoulos, Spiros; Dinoi, Adelaide; Donateo, Antonio; Gregoris, Elena; Karagiannidis, Athanasios; Ivosevic, Tatjana; Liora, Natalia; Melas, Dimitrios; Merico, Eva; Mifka, Boris; Orlic, Ivo; Poupkou, Anastasia; Sarovic, Kristina

2015-04-01

Pollutant emissions from ships and harbour activities constitute an important source of pollution of coastal areas with potential influences on the climate and the health of their inhabitants. A recent review (Viana et al., 2014) shows that these emissions could have an important impact on the Mediterranean and that there is a lack of data for the Eastern and South-Eastern part of this area. This work presents an analysis of the impact of ship emissions to atmospheric particle concentrations (PM) in four important port-cities (Patras Greece, Brindisi and Venice Italy, and Rijeka Croatia) of the Adriatic/Ionian area. The study was performed within the POSEIDON project (Pollution monitoring of ship emissions: an integrated approach for harbours of the Adriatic basin, funded within the MED Programme 2007-2013). The study uses an integrated approach using emission inventories, dispersion modelling and measurements taken at high temporal resolution (1 min) and low temporal resolution for chemical characterization of PM. The emission inventories of the four port-cities show that ships contribute between 11.7% and 31.0% of the total PM emissions being a source locally comparable with road traffic (ranging between 11.8% and 26.6%). The source apportionment using the receptor model PMF showed an oil combustion source (that includes ship emissions), characterized by V and Ni, in Brindisi, Venice and Rijeka with V/Ni ratio ranging between 1.4 and 4.2 indicating local differences in chemical profiles of the emissions. The V concentrations were used to evaluate the contributions of primary ship emissions to PM (Agrawal et al., 2009) that resulted between 1.3% and 2.8%. The contribution to secondary sulphate was 11% of PM2.5 in Brindisi (Cesari et al., 2014). The analysis of high-temporal resolution measurements taken near the harbour areas of Venice, Patras and Brindisi showed a contribution of ship emissions to PM2.5 varying between 3.5% and 7.4%. The relative contribution to particle number concentrations (PNC) was larger at all sites (between 6% and 26%). This demonstrates that ship particulate emissions include mainly small and ultrafine particles. The trend of the impact of passenger ships primary emissions to PM2.5 concentrations in Venice between 2007 and 2012 showed a decrease from 7% (±1%) to 3.5% (±1%) even if the gross tonnage of ship traffic increased in the same period by 47% (Contini et al., 2015). This was a consequence of the use of low-sulphur content fuels due to the application of local mitigation strategies and of the European Directive 2005/33/EC. The WRF-CAMx modeling system was applied over the Central and Eastern Mediterranean so as to identify the air quality impact of ship emissions. The zero-out modelling method was implemented involving model simulations performed while including and omitting the ship emissions. The results for both gaseous and particulate pollutant concentrations generally show a fairly good agreement with observations at the areas under study. Agrawal et al., 2009. Environmental Science and Technology 43, 5398-5402. Cesari et al., 2014. Science of the Total Environment 497-498, 392-400. Contini et al., 2015. Atmospheric Environment 102, 183-190. Viana et al., 2014. Atmospheric Environment 90, 96-105.

40 CFR 63.6612 - By what date must I conduct the initial performance tests or other initial compliance...

Code of Federal Regulations, 2011 CFR

2011-07-01

... stationary RICE with a site rating of less than or equal to 500 brake HP located at a major source of HAP emissions or an existing stationary RICE located at an area source of HAP emissions? 63.6612 Section 63.6612... other initial compliance demonstrations if I own or operate an existing stationary RICE with a site...

40 CFR 63.6612 - By what date must I conduct the initial performance tests or other initial compliance...

Code of Federal Regulations, 2010 CFR

2010-07-01

... stationary RICE with a site rating of less than or equal to 500 brake HP located at a major source of HAP emissions or an existing stationary RICE located at an area source of HAP emissions? 63.6612 Section 63.6612... other initial compliance demonstrations if I own or operate an existing stationary RICE with a site...

Reduction of PM emissions from specific sources reflected on key components concentrations of ambient PM10

NASA Astrophysics Data System (ADS)

Minguillon, M. C.; Querol, X.; Monfort, E.; Alastuey, A.; Escrig, A.; Celades, I.; Miro, J. V.

2009-04-01

The relationship between specific particulate emission control and ambient levels of some PM10 components (Zn, As, Pb, Cs, Tl) was evaluated. To this end, the industrial area of Castellón (Eastern Spain) was selected, where around 40% of the EU glazed ceramic tiles and a high proportion of EU ceramic frits (middle product for the manufacture of ceramic glaze) are produced. The PM10 emissions from the ceramic processes were calculated over the period 2000 to 2007 taking into account the degree of implementation of corrective measures throughout the study period. Abatement systems (mainly bag filters) were implemented in the majority of the fusion kilns for frit manufacture in the area as a result of the application of the Directive 1996/61/CE, leading to a marked decrease in PM10 emissions. On the other hand, ambient PM10 sampling was carried out from April 2002 to July 2008 at three urban sites and one suburban site of the area and a complete chemical analysis was made for about 35 % of the collected samples, by means of different techniques (ICP-AES, ICP-MS, Ion Chromatography, selective electrode and elemental analyser). The series of chemical composition of PM10 allowed us to apply a source contribution model (Principal Component Analysis), followed by a multilinear regression analysis, so that PM10 sources were identified and their contribution to bulk ambient PM10 was quantified on a daily basis, as well as the contribution to bulk ambient concentrations of the identified key components (Zn, As, Pb, Cs, Tl). The contribution of the sources identified as the manufacture and use of ceramic glaze components, including the manufacture of ceramic frits, accounted for more than 65, 75, 58, 53, and 53% of ambient Zn, As, Pb, Cs and Tl levels, respectively (with the exception of Tl contribution at one of the sites). The important emission reductions of these sources during the study period had an impact on ambient key components levels, such that there was a high correlation between PM10 emissions from these sources and ambient key components levels (R2= 0.61-0.98).

Photochemical grid model implementation and application of ...

EPA Pesticide Factsheets

For the purposes of developing optimal emissions control strategies, efficient approaches are needed to identify the major sources or groups of sources that contribute to elevated ozone (O3) concentrations. Source-based apportionment techniques implemented in photochemical grid models track sources through the physical and chemical processes important to the formation and transport of air pollutants. Photochemical model source apportionment has been used to track source impacts of specific sources, groups of sources (sectors), sources in specific geographic areas, and stratospheric and lateral boundary inflow on O3. The implementation and application of a source apportionment technique for O3 and its precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs), for the Community Multiscale Air Quality (CMAQ) model are described here. The Integrated Source Apportionment Method (ISAM) O3 approach is a hybrid of source apportionment and source sensitivity in that O3 production is attributed to precursor sources based on O3 formation regime (e.g., for a NOx-sensitive regime, O3 is apportioned to participating NOx emissions). This implementation is illustrated by tracking multiple emissions source sectors and lateral boundary inflow. NOx, VOC, and O3 attribution to tracked sectors in the application are consistent with spatial and temporal patterns of precursor emissions. The O3 ISAM implementation is further evaluated through comparisons of apportioned am

40 CFR 63.11645 - What are my mercury emission standards?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 14 2011-07-01 2011-07-01 false What are my mercury emission standards... Area Source Category Standards and Compliance Requirements § 63.11645 What are my mercury emission standards? (a) For existing ore pretreatment processes, you must emit no more than 127 pounds of mercury per...

40 CFR 63.11645 - What are my mercury emission standards?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 15 2012-07-01 2012-07-01 false What are my mercury emission standards... Area Source Category Standards and Compliance Requirements § 63.11645 What are my mercury emission standards? (a) For existing ore pretreatment processes, you must emit no more than 127 pounds of mercury per...

40 CFR 63.11645 - What are my mercury emission standards?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 15 2014-07-01 2014-07-01 false What are my mercury emission standards... Area Source Category Standards and Compliance Requirements § 63.11645 What are my mercury emission standards? (a) For existing ore pretreatment processes, you must emit no more than 127 pounds of mercury per...

40 CFR 63.11645 - What are my mercury emission standards?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 15 2013-07-01 2013-07-01 false What are my mercury emission standards... Area Source Category Standards and Compliance Requirements § 63.11645 What are my mercury emission standards? (a) For existing ore pretreatment processes, you must emit no more than 127 pounds of mercury per...

Pilot-scale concept of real-time wind speed-matching wind tunnel for measurements of gaseous emissions

USDA-ARS?s Scientific Manuscript database

Comprehensive control of odors, hydrogen sulfide (H2S), ammonia (NH3) and odorous volatile organic compound (VOC) emissions associated with animal production is a critical need. Current methods utilizing wind tunnels and flux chambers for measurements of gaseous emissions from area sources such as f...

40 CFR Table 2 of Subpart Aaaaaaa... - Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Emission Limits for Asphalt Roofing... Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and... AAAAAAA of Part 63—Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations For * * * 1...

40 CFR Table 2 of Subpart Aaaaaaa... - Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Emission Limits for Asphalt Roofing... Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and... AAAAAAA of Part 63—Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations For * * * 1...

40 CFR Table 2 of Subpart Aaaaaaa... - Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 15 2014-07-01 2014-07-01 false Emission Limits for Asphalt Roofing... Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and... AAAAAAA of Part 63—Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations For * * * 1...

40 CFR Table 2 of Subpart Aaaaaaa... - Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Emission Limits for Asphalt Roofing... Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Other Requirements and... AAAAAAA of Part 63—Emission Limits for Asphalt Roofing Manufacturing (Coating) Operations For * * * 1...

DETERMINATION OF AMMONIA MASS EMISSION FLUX FROM HOG WASTE EFFLUENT SPRAYING OPERATION USING OPEN PATH TUNABLE DIODE LASER SPECTROSCOPY WITH VERTICAL RADIAL PLUME MAPPING ANALYSIS

EPA Science Inventory

Emission of ammonia from concentrated animal feeding operations represents an increasingly important environmental issue. Determination of total ammonia mass emission flux from extended area sources such as waste lagoons and waste effluent spraying operations can be evaluated usi...

IMPLEMENTATION OF THE SMOKE EMISSION DATA PROCESSOR AND SMOKE TOOL INPUT DATA PROCESSOR IN MODELS-3

EPA Science Inventory

The U.S. Environmental Protection Agency has implemented Version 1.3 of SMOKE (Sparse Matrix Object Kernel Emission) processor for preparation of area, mobile, point, and biogenic sources emission data within Version 4.1 of the Models-3 air quality modeling framework. The SMOK...

Vehicle Traffic as a Source of Particulate Polycyclic Aromatic Hydrocarbon Exposure in the Mexico City Metropolitan Area

PubMed Central

MARR, LINSEY C.; GROGAN, LISA A.; WÖHRNSCHIMMEL, HENRY; MOLINA, LUISAT.; MOLINA, MARIO J.; SMITH, THOMAS J.; GARSHICK, ERIC

2005-01-01

Surface properties of aerosols in the Mexico City metropolitan area have been measured in a variety of exposure scenarios related to vehicle emissions in 2002, using continuous, real-time instruments. The objective of these experiments is to describe ambient and occupational particulate polycyclic aromatic hydrocarbon (PAH) concentrations associated with vehicular traffic and facilities using diesel vehicles. Median total particulate PAH concentrations along Mexico City’s roadways range from 60 to 910 ng m−3, averaged over a minimum of 1 h. These levels are approximately 5 times higher than concentrations measured in the United States and among the highest measured ambient values reported in the literature. The ratio of particulate PAH concentration to aerosol active surface area is much higher along roadways and in other areas of fresh vehicle emissions, compared to ratios measured at sites influenced more by aged emissions or noncombustion sources. For particles freshly emitted by vehicles, PAH and elemental carbon (EC) concentrations are correlated because they both originate during the combustion process. Comparison of PAH versus EC and active surface area concentrations at different locations suggests that surface PAH concentrations may diminish with particle aging. These results indicate that exposure to vehicle-related PAH emissions on Mexico City’s roadways may present an important public health risk. PMID:15180054

Spatial and temporal source apportionment of PM2.5 in Georgia, 2002 to 2013

NASA Astrophysics Data System (ADS)

Zhai, Xinxin; Mulholland, James A.; Russell, Armistead G.; Holmes, Heather A.

2017-07-01

The Chemical Mass Balance (CMB) receptor model was applied to estimate PM2.5 source impacts over Georgia from 2002 to 2013 using ambient PM2.5 species concentration data from 13 sites. Measurements of 19 PM2.5 species were used as inputs along with measurement-based source profiles to estimate the impacts of nine sources, including both primary components (from heavy duty diesel vehicle, light duty gasoline vehicle, biomass burning, coal combustion, and suspended dust sources) and secondary pollutants (ammonium sulfate, ammonium bisulfate, ammonium nitrate, and secondary organic carbon). From 2002 to 2013, PM2.5 total mass decreased from 13.8 μg/m3 to 9.2 μg/m3 averaged across all sites, a 33% decrease. Largest decreases were observed for secondary sulfate and nitrate species (58% and 44%, respectively). The amount of neutralization by ammonium did not change substantially over the time period in spite of substantial decreases in sulfate and nitrate concentrations. Total mobile source impacts decreased more at urban sites (39%) than rural sites (23%), whereas biomass burning decreased more at rural sites (34%) than urban sites (27%). The estimated central-site source impacts are found to spatially represent large areas for secondary pollutants, smaller areas for biomass burning and dust, and very local areas for mobile sources and coal combustion. Trends from the National Emissions Inventory were compared with the annual trends of mobile source impacts, coal combustion impacts, and sulfate concentrations, resulting in statistically significant positive trends with Pearson R2 of 0.80, 0.64, and 0.79, respectively. Results presented here suggest that PM2.5 reductions in Georgia and the Southeast have been achieved by control of both stationary and mobile sources, and that PM2.5 is comprised of increasing fractions of biomass burning emissions and suspended dust. The temporal trends of source impacts at each site adds information about source changes beyond the every-three-year emission inventories for evaluation of emission-based model results.

Source data supported high resolution carbon emissions inventory for urban areas of the Beijing-Tianjin-Hebei region: Spatial patterns, decomposition and policy implications.

PubMed

Cai, Bofeng; Li, Wanxin; Dhakal, Shobhakar; Wang, Jianghao

2018-01-15

This paper developed internationally compatible methods for delineating boundaries of urban areas in China. By integrating emission source data with existing official statistics as well as using rescaling methodology of data mapping for 1 km grid, the authors constructed high resolution emission gridded data in Beijing-Tianjin-Hebei (Jing-Jin-Ji) region in China for 2012. Comparisons between urban and non-urban areas of carbon emissions from industry, agriculture, household and transport exhibited regional disparities as well as sectoral differences. Except for the Hebei province, per capita total direct carbon emissions from urban extents in Beijing and Tianjin were both lower than provincial averages, indicating the climate benefit of urbanization, comparable to results from developed countries. Urban extents in the Hebei province were mainly industrial centers while those in Beijing and Tianjin were more service oriented. Further decomposition analysis revealed population to be a common major driver for increased carbon emissions but climate implications of urban design, economic productivity of land use, and carbon intensity of GDP were both cluster- and sector-specific. This study disapproves the one-size-fits-all solution for carbon mitigation but calls for down-scaled analysis of carbon emissions and formulation of localized carbon reduction strategies in the Jing-Jin-Ji as well as other regions in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trends in PM2.5 emissions, concentrations and apportionments in Detroit and Chicago

NASA Astrophysics Data System (ADS)

Milando, Chad; Huang, Lei; Batterman, Stuart

2016-03-01

PM2.5 concentrations throughout much of the U.S. have decreased over the last 15 years, but emissions and concentration trends can vary by location and source type. Such trends should be understood to inform air quality management and policies. This work examines trends in emissions, concentrations and source apportionments in two large Midwest U.S. cities, Detroit, Michigan, and Chicago, Illinois. Annual and seasonal trends were investigated using National Emission Inventory (NEI) data for 2002 to 2011, speciated ambient PM2.5 data from 2001 to 2014, apportionments from positive matrix factorization (PMF) receptor modeling, and quantile regression. Over the study period, county-wide data suggest emissions from point sources decreased (Detroit) or held constant (Chicago), while emissions from on-road mobile sources were constant (Detroit) or increased (Chicago), however changes in methodology limit the interpretation of inventory trends. Ambient concentration data also suggest source and apportionment trends, e.g., annual median concentrations of PM2.5 in the two cities declined by 3.2-3.6%/yr (faster than national trends), and sulfate concentrations (due to coal-fired facilities and other point source emissions) declined even faster; in contrast, organic and elemental carbon (tracers of gasoline and diesel vehicle exhaust) declined more slowly or held constant. The PMF models identified nine sources in Detroit and eight in Chicago, the most important being secondary sulfate, secondary nitrate and vehicle emissions. A minor crustal dust source, metals sources, and a biomass source also were present in both cities. These apportionments showed that the median relative contributions from secondary sulfate sources decreased by 4.2-5.5% per year in Detroit and Chicago, while contributions from metals sources, biomass sources, and vehicles increased from 1.3 to 9.2% per year. This first application of quantile regression to trend analyses of speciated PM2.5 data reveals that source contributions to PM2.5 varied as PM2.5 concentrations decreased, and that the fraction of PM2.5 due to emissions from vehicles and other local emissions has increased. Each data source has uncertainties, but emissions, monitoring and PMF data provide complementary information that can help to discern trends and identify contributing sources. Study results emphasize the need to target specific sources in policies and regulations aimed at decreasing PM2.5 concentrations in urban areas.

DMS emissions from Sphagnum-dominated wetlands

NASA Technical Reports Server (NTRS)

Hines, Mark E.; Demello, William Zamboni; Bayley, Suzanne E.

1992-01-01

The role of terrestrial sources of biogenic S and their effect on atmospheric chemistry remain as major unanswered questions in our understanding of the natural S cycle. The role of northern wetlands as sources and sinks of gaseous S was investigated by measuring rates of S gas exchange as a function of season, hydrologic conditions, and gradients in trophic status. Experiments were conducted in wetlands in New Hampshire (NH), and in Mire 239, a poor fen at the Experimental Lakes Area (ELA) in Ontario. Emissions were determined using Teflon enclosures, gas cryotrapping methods, and GC with flame photometric detection. Emissions of DMS dominated fluxes. In NH, DMS fluxes were greater than 1.6 micromol/m(sup -2)d(sup -1) in early summer, 1989 when temperatures were warm and the water table was approximately 5 cm below the surface. These rates are several-fold faster than average oceanic rates of DMS emission. A rapid drop in the water table resulted in a 6-fold decrease in DMS emissions in late July. In 1990, a new beaver dam kept water levels above the surface and S emissions were much lower than during 1989. The elimination of the beaver and a drop in the water table in August produced a rapid increase in S gas emissions. Emissions of DMS were highest in the most oligotrophic areas. Mire 239 (ELA) was irrigated with sulfuric and nitric acids to simulate acid rain. S emissions were determined before and after an acidification event in control and experimental areas in both minerotrophic and oligotrophic regions. Emissions of DMS were higher in the acidified areas compared to unacidified controls. Emissions were also much higher in the oligotrophic regions compared to the minerotrophic ones. Despite the wide differences in S gas fluxes (20-fold), it was difficult to determine whether acidification or variations in trophic status was not responsible for differences in S gas emissions. DMS emitted into the atmosphere was not derived from the water table but originated in peat in the unsaturated zone.

Area Source Boiler National Emission Standards for Hazardous Air Pollutants (NESHAP), 40 CFR Part 63, Subpart JJJJJJ: Questions and Answers

EPA Pesticide Factsheets

This October 2016 question and answer (Q&A) document is in response to a number of questions the EPA has received from delegated state and local agencies and the regulated community regarding the NESHAP for Area source boilers. Document updates 4/2014 PDF.

Towards Understanding Methane Emissions from Abandoned Wells

EPA Science Inventory

Reconciliation of large-scale top-down methane measurements and bottom-up inventories requires complete accounting of source types. Methane emissions from abandoned oil and gas wells is an area of uncertainty. This presentation reviews progress to characterize the potential inv...

Sensitivities of NOx transformation and the effects on surface ozone and nitrate

NASA Astrophysics Data System (ADS)

Lei, H.; Wang, J. X. L.

2014-02-01

As precursors to tropospheric ozone and nitrate, nitrogen oxide (NOx) in the present atmosphere and its transformation in response to emission and climate perturbations are studied by using the CAM-Chem model and air quality measurements from the National Emissions Inventory (NEI), Clean Air Status and Trends Network (CASTNET), and Environmental Protection Agency Air Quality System (EPA AQS). It is found that NOx transformations in present atmospheric conditions show different sensitivities over industrial and non-industrial regions. As a result, the surface ozone and nitrate formations can be divided into several regimes associated with the dominant emission types and relative levels of NOx and volatile organic compounds (VOC). Ozone production in industrial regions (the main NOx emission source areas) increases in warmer conditions and slightly decreases following an increase in NOx emissions due to NOx titration, which is opposite to the response in non-industrial regions. The ozone decrease following a temperature increase in non-industrial regions indicates that ozone production in regions that lack NOx emission sources may be sensitive to NOx transformation in remote source regions. The increase in NO2 from NOx titration over industrial regions results in an increase rate of total nitrate that remains higher than the increase rate of NOx emissions. The presented findings indicate that a change in the ozone concentration is more directly affected by changes in climate and precursor emissions, while a change in the nitrate concentration is affected by local ozone production types and their seasonal transfer. The sensitivity to temperature perturbations shows that a warmer climate accelerates the decomposition of odd nitrogen (NOy) during the night. As a result, the transformation rate of NOx to nitrate decreases. Examinations of the historical emissions and air quality records of a typical NOx-limited area, such as Atlanta and a VOC-limited area, such as Los Angeles further confirm the conclusions drawn from the modeling experiments.

Wildfires in northern Eurasia affect the budget of black carbon in the Arctic - a 12-year retrospective synopsis (2002-2013)

NASA Astrophysics Data System (ADS)

Evangeliou, N.; Balkanski, Y.; Hao, W. M.; Petkov, A.; Silverstein, R. P.; Corley, R.; Nordgren, B. L.; Urbanski, S. P.; Eckhardt, S.; Stohl, A.; Tunved, P.; Crepinsek, S.; Jefferson, A.; Sharma, S.; Nøjgaard, J. K.; Skov, H.

2016-06-01

In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in northern Eurasia during the period of 2002-2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory - northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (Moderate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were adopted from the MACCity (Monitoring Atmospheric Composition and Climate and megacity Zoom for the Environment) emission inventory.During the 12-year period, an average area of 250 000 km2 yr-1 was burned in northern Eurasia (FEI-NE) and the global emissions of BC ranged between 8.0 and 9.5 Tg yr-1 (FEI-NE+MACCity). For the BC emitted in the Northern Hemisphere (based on FEI-NE+MACCity), about 70 % originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE+MACCity inventory, we found that 102 ± 29 kt yr-1 BC was deposited in the Arctic (defined here as the area north of 67° N) during the 12 years simulated, which was twice as much as when using the MACCity inventory (56 ± 8 kt yr-1). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in northern Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009 (78 vs. 57 kt yr-1) to 181 % in 2012 (153 vs. 54 kt yr-1), compared to the BC deposited using just the MACCity emission inventory. Deposition of BC in the Arctic from BB sources in the Northern Hemisphere thus represents 68 % of the BC deposited from all BC sources (the remaining being due to anthropogenic sources). Northern Eurasian vegetation fires (FEI-NE) contributed 85 % (79-91 %) to the BC deposited over the Arctic from all BB sources in the Northern Hemisphere.We estimate that about 46 % of the BC deposited over the Arctic from vegetation fires in northern Eurasia originated from Siberia, 6 % from Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining 42 % originated from other areas in northern Eurasia. About 42 % of the BC released from northern Eurasian vegetation fires was deposited over the Arctic (annual average: 17 %) during spring and summer.

Source contributions to United States ozone and particulate matter over five decades from 1970 to 2020

NASA Astrophysics Data System (ADS)

Nopmongcol, Uarporn; Alvarez, Yesica; Jung, Jaegun; Grant, John; Kumar, Naresh; Yarwood, Greg

2017-10-01

Evaluating long-term air quality trends can demonstrate effectiveness of control strategies and guide future air quality management planning. Observations have shown that ozone (O3) and fine particulate matter (PM2.5) in the US have declined since as early as 1980 in some areas. But observation trends alone cannot separate effects of changes in local and global emissions to US air quality which are important to air quality planners. This study uses a regional model (CAMx) nested within a global model (GEOS-Chem) to characterize regional changes in O3 and PM2.5 due to the intercontinental transport and local/regional emissions representing six modeling years within five decades (1970-2020). We use the CAMx Source Apportionment Technology (OSAT/PSAT) to estimate contributions from 6 source sectors in 7 source regions plus 6 other groups for a total of 48 tagged contributions. On-road mobile sources consistently make the largest U.S. anthropogenic emissions contribution to O3 in all cities examined even though they decline substantially from 1970 to 2005 and also from 2005 to 2020. Off-road mobile source contributions increase from 1970 to 2005 and then decrease after 2005 in all of the cities. The boundary conditions, mostly from intercontinental transport, contribute more than 20 ppb to high maximum daily 8-h average (MDA8) O3 for all six years. We found that lowering NOx emissions raises O3 formation efficiency (OFE) across all emission categories which will limit potential O3 benefits of local NOx strategies in the near future. PM2.5 benefited from adoption of control devices between 1970 and 1980 and has continued to decline through 2005 and expected to decline further by 2020. Area sources such as residential, commercial and fugitive dust emissions stand out as making large contributions to PM2.5 that are not declining. Inter-regional transport is less important in 2020 than 1990 for both pollutants.

Some Aspects of the Radio Emission of EGRET-Detected Blazars

NASA Technical Reports Server (NTRS)

Lin, Y. C.; Bertsch, D. L.; Bloom, S. D.; Esposito, J. A.; Hartman, R. C.; Hunter, S. D.; Kniffen, D. A.; Kanbach, G.; Mayer-Hasselwander, H. A.; Michelson, P. F.

1999-01-01

It has long been recognized that the high-latitude Energetic Gamma Ray Experiment Telescope (EGRET) sources can be identified with blazars of significant radio emission. Many aspects of the relation between high-energy gamma-ray emission and radio emission of EGRET-detected blazars remain uncertain. In this paper, we use the results of the recently published Third EGRET Source Catalog to examine in more detail to what extent the EGRET flux and the radio flux are correlated. In particular we examine the correlation (or the lack of it) in flux level, spectral shape, temporal variation, and detection limit. Many significant previous studies in these areas are also evaluated.

Relative impact of on-road vehicular and point-source industrial emissions of air pollutants in a medium-sized Andean city

NASA Astrophysics Data System (ADS)

González, C. M.; Gómez, C. D.; Rojas, N. Y.; Acevedo, H.; Aristizábal, B. H.

2017-03-01

Cities in emerging countries are facing a fast growth and urbanization; however, the study of air pollutant emissions and its dynamics is scarce, making their populations vulnerable to potential effects of air pollution. This situation is critical in medium-sized urban areas built along the tropical Andean mountains. This work assesses the contribution of on-road vehicular and point-source industrial activities in the medium-sized Andean city of Manizales, Colombia. Annual fluxes of criteria pollutants, NMVOC, and greenhouse gases were estimated. Emissions were dominated by vehicular activity, with more than 90% of total estimated releases for the majority of air pollutants. On-road vehicular emissions for CO (43.4 Gg/yr) and NMVOC (9.6 Gg/yr) were mainly associated with the use of motorcycles (50% and 81% of total CO and NMVOC emissions respectively). Public transit buses were the main source of PM10 (47%) and NOx (48%). The per-capita emission index was significantly higher in Manizales than in other medium-sized cities, especially for NMVOC, CO, NOx and CO2. The unique mountainous terrain of Andean cities suggest that a methodology based on VSP model could give more realistic emission estimates, with additional model components that include slope and acceleration. Food and beverage facilities were the main contributors of point-source industrial emissions for PM10 (63%), SOx (55%) and NOx (45%), whereas scrap metal recycling had high emissions of CO (73%) and NMVOC (47%). Results provide the baseline for ongoing research in atmospheric modeling and urban air quality, in order to improve the understanding of air pollutant fluxes, transport and transformation in the atmosphere. In addition, this emission inventory could be used as a tool to identify areas of public health exposure and provide information for future decision makers.

Sources and geographic origin of particulate matter in urban areas of the Danube macro-region: The cases of Zagreb (Croatia), Budapest (Hungary) and Sofia (Bulgaria).

PubMed

Perrone, M G; Vratolis, S; Georgieva, E; Török, S; Šega, K; Veleva, B; Osán, J; Bešlić, I; Kertész, Z; Pernigotti, D; Eleftheriadis, K; Belis, C A

2018-04-01

The contribution of main PM pollution sources and their geographic origin in three urban sites of the Danube macro-region (Zagreb, Budapest and Sofia) were determined by combining receptor and Lagrangian models. The source contribution estimates were obtained with the Positive Matrix Factorization (PMF) receptor model and the results were further examined using local wind data and backward trajectories obtained with FLEXPART. Potential Source Contribution Function (PSCF) analysis was applied to identify the geographical source areas for the PM sources subject to long-range transport. Gas-to-particle transformation processes and primary emissions from biomass burning are the most important contributors to PM in the studied sites followed by re-suspension of soil (crustal material) and traffic. These four sources can be considered typical of the Danube macro-region because they were identified in all the studied locations. Long-range transport was observed of: a) sulphate-enriched aged aerosols, deriving from SO 2 emissions in combustion processes in the Balkans and Eastern Europe and b) dust from the Saharan and Karakum deserts. The study highlights that PM pollution in the studied urban areas of the Danube macro-region is the result of both local sources and long-range transport from both EU and no-EU areas. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. L. Lewicki; G. E. Hilley; L. Dobeck

A set of CO2 flux, geochemical, and hydrologic measurement techniques was used to characterize the source of and quantify gaseous and dissolved CO2 discharges from the area of Soda Springs, southeastern Idaho. An eddy covariance system was deployed for approximately one month near a bubbling spring and measured net CO2 fluxes from - 74 to 1147 g m- 2 d- 1. An inversion of measured eddy covariance CO2 fluxes and corresponding modeled source weight functions mapped the surface CO2 flux distribution within and quantified CO2 emission rate (24.9 t d- 1) from a 0.05 km2 area surrounding the spring. Soilmore » CO2 fluxes (< 1 to 52,178 g m- 2 d- 1) were measured within a 0.05 km2 area of diffuse degassing using the accumulation chamber method. The estimated CO2 emission rate from this area was 49 t d- 1. A carbon mass balance approach was used to estimate dissolved CO2 discharges from contributing sources at nine springs and the Soda Springs geyser. Total dissolved inorganic carbon (as CO2) discharge for all sampled groundwater features was 57.1 t d- 1. Of this quantity, approximately 3% was derived from biogenic carbon dissolved in infiltrating groundwater, 35% was derived from carbonate mineral dissolution within the aquifer(s), and 62% was derived from deep source(s). Isotopic compositions of helium (1.74–2.37 Ra) and deeply derived carbon (d13C approximately 3‰) suggested contribution of volatiles from mantle and carbonate sources. Assuming that the deeply derived CO2 discharge estimated for sampled groundwater features (approximately 35 t d- 1) is representative of springs throughout the study area, the total rate of deeply derived CO2 input into the groundwater system within this area could be ~ 350 t d- 1, similar to CO2 emission rates from a number of quiescent volcanoes.« less

High Background Ozone Events in the Houston-Galveston-Brazoria Area: Effects from Central American Fires

NASA Astrophysics Data System (ADS)

Lei, R.; Wang, S. C.; Yang, S.; Wang, Y.; Talbot, R. W.

2016-12-01

The policy-relevant background (PRB) ozone is defined by the U.S. Environmental Protection Agency (EPA) as the surface ozone mixing ratio that would occur over the U.S. without North American anthropogenic emission influences. PRB ozone over the Houston-Galveston-Brazoria (HGB) area may be affected by foreign sources due to its unique geographical location and meteorology. Our monitoring data revealed several high ozone events over HGB area which might be caused by Central American fire during the years of 2013-2015. To qualify the effects from Central American fire, we estimated the US, Central American and worldwide background over HGB area during those events using the GEOS-Chem global 3-D model. Anomalies in fire emissions leading to high PRB ozone were mapped through spatiotemporal sampling of the Fire INventory from NCAR (FINN) along background trajectories of air masses affecting the HGB area prior to and during the selected high PRB ozone days. Daily HGB PRB ozone estimated by researchers at the Texas Commission on Environmental Quality (TCEQ) was used as the data source to validate model results. Results showed that contribution of emission from Central American to HGB PRB ozone could be tripled during fire events compared to non-impacted fire days. Besides fire emissions from Central American, different types of meteorological events (e.g., cold fronts and thunderstorms) and high local photochemical production (e.g., heat waves and stagnation) are also found associated with high PRB ozone in HGB area during these events. Thus we imply that synthetic contribution from foreign sources and local meteorology to HGB PRB ozone warrants further investigated.

Global Occurrence and Emission of Rotaviruses to Surface Waters

PubMed Central

Kiulia, Nicholas M.; Hofstra, Nynke; Vermeulen, Lucie C.; Obara, Maureen A.; Medema, Gertjan; Rose, Joan B.

2015-01-01

Group A rotaviruses (RV) are the major cause of acute gastroenteritis in infants and young children globally. Waterborne transmission of RV and the presence of RV in water sources are of major public health importance. In this paper, we present the Global Waterborne Pathogen model for RV (GloWPa-Rota model) to estimate the global distribution of RV emissions to surface water. To our knowledge, this is the first model to do so. We review the literature to estimate three RV specific variables for the model: incidence, excretion rate and removal during wastewater treatment. We estimate total global RV emissions to be 2 × 1018 viral particles/grid/year, of which 87% is produced by the urban population. Hotspot regions with high RV emissions are urban areas in densely populated parts of the world, such as Bangladesh and Nigeria, while low emissions are found in rural areas in North Russia and the Australian desert. Even for industrialized regions with high population density and without tertiary treatment, such as the UK, substantial emissions are estimated. Modeling exercises like the one presented in this paper provide unique opportunities to further study these emissions to surface water, their sources and scenarios for improved management. PMID:25984911

Historic emissions from deforestation and forest degradation in Mato Grosso, Brazil: 1) source data uncertainties

PubMed Central

2011-01-01

Background Historic carbon emissions are an important foundation for proposed efforts to Reduce Emissions from Deforestation and forest Degradation and enhance forest carbon stocks through conservation and sustainable forest management (REDD+). The level of uncertainty in historic carbon emissions estimates is also critical for REDD+, since high uncertainties could limit climate benefits from credited mitigation actions. Here, we analyzed source data uncertainties based on the range of available deforestation, forest degradation, and forest carbon stock estimates for the Brazilian state of Mato Grosso during 1990-2008. Results Deforestation estimates showed good agreement for multi-year periods of increasing and decreasing deforestation during the study period. However, annual deforestation rates differed by > 20% in more than half of the years between 1997-2008, even for products based on similar input data. Tier 2 estimates of average forest carbon stocks varied between 99-192 Mg C ha-1, with greatest differences in northwest Mato Grosso. Carbon stocks in deforested areas increased over the study period, yet this increasing trend in deforested biomass was smaller than the difference among carbon stock datasets for these areas. Conclusions Estimates of source data uncertainties are essential for REDD+. Patterns of spatial and temporal disagreement among available data products provide a roadmap for future efforts to reduce source data uncertainties for estimates of historic forest carbon emissions. Specifically, regions with large discrepancies in available estimates of both deforestation and forest carbon stocks are priority areas for evaluating and improving existing estimates. Full carbon accounting for REDD+ will also require filling data gaps, including forest degradation and secondary forest, with annual data on all forest transitions. PMID:22208947

Comparison of precipitation chemistry in the Central Rocky Mountains, Colorado, USA

USGS Publications Warehouse

Heuer, K.; Tonnessen, K.A.; Ingersoll, G.P.

2000-01-01

Volume-weighted mean concentrations of nitrate (NO3-), ammonium (NH4+), and sulfate (SO42-) in precipitation were compared at high-elevation sites in Colorado from 1992 to 1997 to evaluate emission source areas to the east and west of the Rocky Mountains. Precipitation chemistry was measured by two sampling methods, the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) and snowpack surveys at maximum accumulation. Concentrations of NO3- and SO42- in winter precipitation were greater on the western slope of the Rockies, and concentrations of NO3- and NH4+ in summer precipitation were greater on the eastern slope. Summer concentrations in general were almost twice as high as winter concentrations. Seasonal weather patterns in combination with emission source areas help to explain these differences. This comparison shows that high-elevation ecosystems in Colorado are influenced by air pollution emission sources located on both sides of the Continental Divide. It also suggests that sources of nitrogen and sulfur located east of the Divide have a greater influence on precipitation chemistry in the Colorado Rockies. Copyright (C) 2000.

Combining emission inventory and isotope ratio analyses for quantitative source apportionment of heavy metals in agricultural soil.

PubMed

Chen, Lian; Zhou, Shenglu; Wu, Shaohua; Wang, Chunhui; Li, Baojie; Li, Yan; Wang, Junxiao

2018-08-01

Two quantitative methods (emission inventory and isotope ratio analysis) were combined to apportion source contributions of heavy metals entering agricultural soils in the Lihe River watershed (Taihu region, east China). Source apportionment based on the emission inventory method indicated that for Cd, Cr, Cu, Pb, and Zn, the mean percentage input from atmospheric deposition was highest (62-85%), followed by irrigation (12-27%) and fertilization (1-14%). Thus, the heavy metals were derived mainly from industrial activities and traffic emissions. For Ni the combined percentage input from irrigation and fertilization was approximately 20% higher than that from atmospheric deposition, indicating that Ni was mainly derived from agricultural activities. Based on isotope ratio analysis, atmospheric deposition accounted for 57-93% of Pb entering soil, with the mean value of 69.3%, which indicates that this was the major source of Pb entering soil in the study area. The mean contributions of irrigation and fertilization to Pb pollution of soil ranged from 0% to 10%, indicating that they played only a marginally important role. Overall, the results obtained using the two methods were similar. This study provides a reliable approach for source apportionment of heavy metals entering agricultural soils in the study area, and clearly have potential application for future studies in other regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sources of nitrogen and phosphorus emissions to Irish rivers: estimates from the Source Load Apportionment Model (SLAM)

NASA Astrophysics Data System (ADS)

Mockler, Eva; Deakin, Jenny; Archbold, Marie; Daly, Donal; Bruen, Michael

2017-04-01

More than half of the river and lake water bodies in Europe are at less than good ecological status or potential, and diffuse pollution from agriculture remains a major, but not the only, cause of this poor performance. In Ireland, it is evident that agri-environmental policy and land management practices have, in many areas, reduced nutrient emissions to water, mitigating the potential impact on water quality. However, additional measures may be required in order to further decouple the relationship between agricultural productivity and emissions to water, which is of vital importance given the on-going agricultural intensification in Ireland. Catchment management can be greatly supported by modelling, which can reduce the resources required to analyse large amounts of information and can enable investigations and measures to be targeted. The Source Load Apportionment Model (SLAM) framework was developed to support catchment management in Ireland by characterising the contributions from various sources of phosphorus (P) and nitrogen (N) emissions to water. The SLAM integrates multiple national spatial datasets relating to nutrient emissions to surface water, including land use and physical characteristics of the sub-catchments to predict emissions from point (wastewater, industry discharges and septic tank systems) and diffuse sources (agriculture, forestry, peatlands, etc.). The annual nutrient emissions predicted by the SLAM were assessed against nutrient monitoring data for 16 major river catchments covering 50% of the area of Ireland. At national scale, results indicate that the total average annual emissions to surface water in Ireland are over 2,700 t yr-1 of P and 80,000 t yr-1 of N. The SLAM results include the proportional contributions from individual sources at a range of scales from sub-catchment to national, and show that the main sources of P are from wastewater and agriculture, with wide variations across the country related to local anthropogenic pressures and the hydrogeological setting. Agriculture is the main source of N emissions to water across all regions of Ireland. The SLAM results have been incorporated into an Integrated Catchment Management process and used in conjunction with monitoring data and local knowledge during the characterisation of all Irish water bodies by the Environmental Protection Agency. This demonstrates the successful integration of research into catchment management to inform the identification of (i) the sources of nutrients at regional and local scales and (ii) the potential significant pressures and appropriate mitigation measures.

Eddy covariance measurement of CO2 flux to the atmosphere from a area of high volcanogenic emissions, Mammoth Mountain, California

USGS Publications Warehouse

Anderson, D.E.; Farrar, C.D.

2001-01-01

Three pilot studies were performed to assess application of the eddy covariance micrometeorological method in the measurement of carbon dioxide (CO2) flux of volcanic origin. The selected study area is one of high diffuse CO2 emission on Mammoth Mountain, CA. Because terrain and source characteristics make this a complex setting for this type of measurement, added consideration was given to source area and upwind fetch. Footprint analysis suggests that the eddy covariance measurements were representative of an upwind elliptical source area (3.8 ?? 103 m2) which can vary with mean wind direction, surface roughness, and atmospheric stability. CO2 flux averaged 8-16 mg m-2 s-1 (0.7-1.4 kg m-2 day-1). Eddy covariance measurements of flux were compared with surface chamber measurements made in separate studies [Geophys. Res. Lett. 25 (1998a) 1947; EOS Trans. 79 (1998) F941.] and were found to be similar. ?? 2001 Elsevier Science B.V. All rights reserved.

Time correlations between low and high energy gamma rays from discrete sources

NASA Technical Reports Server (NTRS)

Ellsworth, R. W.

1995-01-01

Activities covered the following areas: (1) continuing analysis of the Cygnus Experiment data on the shadowing of cosmic rays by the moon and sun, which led to a direct confirmation of the angular resolution of the CYGNUS EAS array; and (2) development of analysis methods for the daily search overlapping with EGRET targets. To date, no steady emission of ultrahigh energy (UHE) gamma rays from any source has been detected by the Cygnus Experiment, but some evidence for sporadic emission had been found. Upper limits on steady fluxes from 49 sources in the northern hemisphere have been published. In addition, a daily search of 51 possible sources over the interval April 1986 to June 1992 found no evidence for emission. From these source lists, four candidates were selected for comparison with EGRET data.

Evaluation of particulate matter emissions from manganese alloy production using life-cycle assessment.

PubMed

Davourie, Julia; Westfall, Luke; Ali, Mohammed; McGough, Doreen

2017-01-01

Life-cycle assessments (LCAs) provide a wealth of industry data to assist in evaluating the environmental impacts of industrial processes and product supply chains. In this investigation, data from a recent LCA covering global manganese alloy production was used to evaluate sources of particulate matter (PM) emissions associated with the manganese alloy supply chain. The analysis is aimed at providing an empirical, industry-averaged breakdown of the contribution that processes and emissions controls have on total emissions, manganese releases and occupational exposure. The assessment shows that 66% of PM emissions associated with manganese production occur beyond manganese facilities. Direct or on-site emissions represent 34% of total PM and occur predominantly as disperse sources during mineral extraction and hauling, and as primary furnace emissions. The largest contribution of manganese-bearing PM at ground-level is associated with fugitive emissions from metal and slag tapping, casting, crushing and screening. The evaluation provides a high-level ranking of emissions by process area, to assist in identifying priority areas for industry-wide initiatives to reduce emissions and occupational exposure of manganese. The range of PM emission levels in industry indicate that further enhancements in PM emissions can be achieved by sharing of best practices in emissions controls, limiting furnace conditions which lead to by-passing of emissions controls and application of secondary emission controls to capture fugitive emissions during tapping and casting. The LCA approach to evaluating PM emissions underscores the important role that process optimization and resource efficiency have on reducing PM emissions throughout the manganese supply chain. Copyright © 2016. Published by Elsevier B.V.

Characterization of exhaust emissions from heavy-duty diesel vehicles in the HGB area : final report.

DOT National Transportation Integrated Search

2012-02-01

The relative contribution of heavy-duty diesel vehicles (HDDVs) to mobile source emissions has grown : significantly over the past decade, and certain vehicles identified as high emitting vehicles (HEs) contribute : disproportionately to the overall ...

40 CFR 63.11158 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

...? 63.11158 Section 63.11158 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Secondary Copper Smelting Area...

40 CFR 63.11158 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

...? 63.11158 Section 63.11158 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Secondary Copper Smelting Area...

40 CFR 63.11158 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

...? 63.11158 Section 63.11158 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Secondary Copper Smelting Area...

40 CFR 63.11457 - What are the recordkeeping requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area... calibration and maintenance records. (7) For each bag leak detection system, the records specified in...

40 CFR 63.11457 - What are the recordkeeping requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area... calibration and maintenance records. (7) For each bag leak detection system, the records specified in...

40 CFR 63.11457 - What are the recordkeeping requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area... calibration and maintenance records. (7) For each bag leak detection system, the records specified in...

40 CFR 63.11457 - What are the recordkeeping requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Glass Manufacturing Area... calibration and maintenance records. (7) For each bag leak detection system, the records specified in...

Wildland fire emissions, carbon, and climate: wildland fire detection and burned area in the United States

Treesearch

Wei Min Hao; Narasimhan K. Larkin

2014-01-01

Biomass burning is a major source of greenhouse gases, aerosols, black carbon, and atmospheric pollutants that affects regional and global climate and air quality. The spatial and temporal extent of fires and the size of burned areas are critical parameters in the estimation of fire emissions. Tremendous efforts have been made in the past 12 years to characterize the...

Fermi Large Area Telescope third source catalog

DOE PAGES

Acero, F.; Ackermann, M.; Ajello, M.; ...

2015-06-12

Here, we present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in the 100 MeV–300 GeV range. Based on the first 4 yr of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the Second Fermi LAT catalog, the 3FGL catalog incorporates twice as much data, as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse γ-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources abovemore » $$4\\sigma $$ significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 238 sources are considered as identified based on angular extent or correlated variability (periodic or otherwise) observed at other wavelengths. For 1010 sources we have not found plausible counterparts at other wavelengths. More than 1100 of the identified or associated sources are active galaxies of the blazar class; several other classes of non-blazar active galaxies are also represented in the 3FGL. Pulsars represent the largest Galactic source class. As a result, from source counts of Galactic sources we estimate that the contribution of unresolved sources to the Galactic diffuse emission is ~3% at 1 GeV.« less

Evaluation of On-Road Vehicle Emission Trends in the United States

NASA Astrophysics Data System (ADS)

Harley, R. A.; Dallmann, T. R.; Kirchstetter, T.

2010-12-01

Mobile sources contribute significantly to emissions of nitrogen oxides (NOx), carbon monoxide (CO), fine particulate matter (PM2.5), and black carbon (BC). These emissions lead to a variety of environmental problems including air pollution and climate change. At present, national and state-level mobile source emission inventories are developed using statistical models to predict emissions from large and diverse populations of vehicles. Activity is measured by total vehicle-km traveled, and pollutant emission factors are predicted based on laboratory testing of individual vehicles. Despite efforts to improve mobile source emission inventories, they continue to have large associated uncertainties. Alternate methods, such as the fuel-based approach used here, are needed to evaluate estimates of mobile source emissions and to help reduce uncertainties. In this study we quantify U.S. national emissions of NOx, CO, PM2.5, and BC from on-road diesel and gasoline vehicles for the years 1990-2010, including effects of a weakened national economy on fuel sales and vehicle travel from 2008-10. Pollutant emissions are estimated by multiplying total amounts of fuel consumed with emission factors expressed per unit of fuel burned. Fuel consumption is used as a measure of vehicle activity, and is based on records of taxable fuel sales. Pollutant emission factors are derived from roadside and tunnel studies, remote sensing measurements, and individual vehicle exhaust plume capture experiments. Emission factors are updated with new results from a summer 2010 field study conducted at the Caldecott tunnel in the San Francisco Bay Area.

75 FR 28227 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... published a proposed rule for mercury emissions from the gold mine ore processing and production area source... proposed rule (75 FR 22470). Several parties requested that EPA extend the comment period. EPA has granted...-AP48 National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...

Near-source mobile methane emission estimates using EPA Method33a and a novel probabilistic approach as a basis for leak quantification in urban areas

EPA Science Inventory

Methane emissions from underground pipeline leaks remain an ongoing issue in the development of accurate methane emission inventories for the natural gas supply chain. Application of mobile methods during routine street surveys would help address this issue, but there are large ...

Identifying Anthropogenic Emissions of Atmospheric Mercury and Methane in Urban Houston Using Measurements from A Mobile Laboratory

NASA Astrophysics Data System (ADS)

Lan, X.; Laine, P. L.; Talbot, R. W.; Lefer, B. L.; Flynn, J. H.; Sive, B. C.

2013-12-01

The Houston area is heavily polluted with more than 400 refineries and other industrial facilities in the surrounding regions. From our 2-year continuous measurements at this area, we observed frequent occurrences of large peaks in both atmospheric mercury and methane. The highest elemental mercury level we observed was 27,327 ppqv, and the highest CH4 level reached 25 ppmv. We found that some mercury spikes occurred simultaneously with peaks in CH4, CO, CO2, and NO. Many high mercury episodes showed different features of CO, CO2, CH4, NOx and SO2, indicating contributions from different sources. To identify and quantify the sources of mercury and methane in this area, a mobile van equipped with mercury instruments together with CH4, CO2, δ13CH4, δ13CO2 (Picarro G2201-i), and CO, O3, and NOx will be used to sample the emissions from surrounding oil refineries facilities, natural gas processing plants, coal-fired power plants, sewage treatment plants, landfills, petrochemical manufacturing facilities, etc. A Proton Transfer Reaction Mass Spectrometer is also equipped in the mobile van to measure some VOCs species, such as benzene, toluene, isoprene, acetaldehyde, formaldehyde, methanol, acetone, MVK, MEK+MACR, C8 aromatics. The CH4 isotopic and VOCs signatures, and the ratios of mercury versus important species (i.e., CO and CO2) will help us to identify the mercury and methane sources, to investigate the methane leakage problem from natural gas operations, and improve the mercury and methane emission inventories in Houston area. We believe this study will also provide important information on industrial emissions that are missing from the EPA National Emission Inventory.

Effects of Grid Resolution on Modeled Air Pollutant Concentrations Due to Emissions from Large Point Sources: Case Study during KORUS-AQ 2016 Campaign

NASA Astrophysics Data System (ADS)

Ju, H.; Bae, C.; Kim, B. U.; Kim, H. C.; Kim, S.

2017-12-01

Large point sources in the Chungnam area received a nation-wide attention in South Korea because the area is located southwest of the Seoul Metropolitan Area whose population is over 22 million and the summertime prevalent winds in the area is northeastward. Therefore, emissions from the large point sources in the Chungnam area were one of the major observation targets during the KORUS-AQ 2016 including aircraft measurements. In general, horizontal grid resolutions of eulerian photochemical models have profound effects on estimated air pollutant concentrations. It is due to the formulation of grid models; that is, emissions in a grid cell will be assumed to be mixed well under planetary boundary layers regardless of grid cell sizes. In this study, we performed series of simulations with the Comprehensive Air Quality Model with eXetension (CAMx). For 9-km and 3-km simulations, we used meteorological fields obtained from the Weather Research and Forecast model while utilizing the "Flexi-nesting" option in the CAMx for the 1-km simulation. In "Flexi-nesting" mode, CAMx interpolates or assigns model inputs from the immediate parent grid. We compared modeled concentrations with ground observation data as well as aircraft measurements to quantify variations of model bias and error depending on horizontal grid resolutions.

Anthropogenic and natural methane emissions from a shale gas exploration area of Quebec, Canada.

PubMed

Pinti, Daniele L; Gelinas, Yves; Moritz, Anja M; Larocque, Marie; Sano, Yuji

2016-10-01

The increasing number of studies on the determination of natural methane in groundwater of shale gas prospection areas offers a unique opportunity for refining the quantification of natural methane emissions. Here methane emissions, computed from four potential sources, are reported for an area of ca. 16,500km(2) of the St. Lawrence Lowlands, Quebec (Canada), where Utica shales are targeted by the petroleum industry. Methane emissions can be caused by 1) groundwater degassing as a result of groundwater abstraction for domestic and municipal uses; 2) groundwater discharge along rivers; 3) migration to the surface by (macro- and micro-) diffuse seepage; 4) degassing of hydraulic fracturing fluids during first phases of drilling. Methane emissions related to groundwater discharge to rivers (2.47×10(-4) to 9.35×10(-3)Tgyr(-1)) surpass those of diffuse seepage (4.13×10(-6) to 7.14×10(-5)Tgyr(-1)) and groundwater abstraction (6.35×10(-6) to 2.49×10(-4)Tgyr(-1)). The methane emission from the degassing of flowback waters during drilling of the Utica shale over a 10- to 20-year horizon is estimated from 2.55×10(-3) to 1.62×10(-2)Tgyr(-1). These emissions are from one third to sixty-six times the methane emissions from groundwater discharge to rivers. This study shows that different methane emission sources need to be considered in environmental assessments of methane exploitation projects to better understand their impacts. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial distribution of source locations for particulate nitrate and sulfate in the upper-midwestern United States

NASA Astrophysics Data System (ADS)

Zhao, Weixiang; Hopke, Philip K.; Zhou, Liming

Two back-trajectory analysis methods designed to be used with multiple site data, simplified quantitative transport bias analysis (SQTBA) and residence time weighted concentration (RTWC), were applied to nitrate and sulfate concentration data from two rural sites (the Mammoth Cave National Park and the Great Smoky Mountain National Park) and five urban sites (Chicago, Cleveland, Detroit, Indianapolis, and St. Louis) for an intensive investigation on the spatial patterns of origins for these two species in the upper-midwestern area. The study was made by dividing the data into five categories: all sites and all seasons, rural sites in summer, rural sites in winter, urban sites in summer, and urban sites in winter. A general conclusion was that the origins of the nitrate in these seven sites were mainly in the upper-midwestern areas, while the sulfate in these seven sites were mainly from the Ohio and Tennessee River Valley areas. The upper-midwestern areas are regions of high ammonia emissions rather than high NO x emissions. In the winter, metropolitan areas showed the highest nitrate emission potential suggesting the importance of local NO x emissions. In the summer, ammonia emissions from fertilizer application in the lower midwestern area made a significant contribution to nitrate in the rural sites of this study. The impact of the wind direction prevalence on the source spatial patterns was observed by comparing the urban and rural patterns of the summer. The differences between the results of two methods are discussed and suggestions for applying these methods are also provided.

Hydrogen stable isotopic constraints on methane emissions from oil and gas extraction in the Colorado Front Range, USA

NASA Astrophysics Data System (ADS)

Townsend-Small, A.; Botner, E. C.; Jimenez, K.; Blake, N. J.; Schroeder, J.; Meinardi, S.; Barletta, B.; Simpson, I. J.; Blake, D. R.; Flocke, F. M.; Pfister, G.; Bon, D.; Crawford, J. H.

2015-12-01

The climatic implications of a shift from oil and coal to natural gas depend on the magnitude of fugitive emissions of methane from the natural gas supply chain. Attempts to constrain methane emissions from natural gas production regions can be confounded by other sources of methane. Here we demonstrate the utility of stable isotopes, particularly hydrogen isotopes, for source apportionment of methane emissions. The Denver, Colorado area is home to a large oil and gas field with both conventional oil and gas wells and newer hydraulic fracturing wells. The region also has a large metropolitan area with several landfills and a sizable cattle population. As part of the DISCOVER-AQ and FRAPPE field campaigns in summer 2014, we collected three types of canister samples for analysis of stable isotopic composition of methane: 1), samples from methane sources; 2), samples from two stationary ground sites, one in the Denver foothills, and one in an oil and gas field; and 3), from the NCAR C-130 aircraft in samples upwind and downwind of the region. Our results indicate that hydrogen isotope ratios are excellent tracers of sources of methane in the region, as we have shown previously in California and Texas. Use of carbon isotope ratios is complicated by the similarity of natural gas isotope ratios to that of background methane. Our results indicate that, despite the large amount of natural gas production in the region, biological sources such as cattle feedlots and landfills account for at least 50% of total methane emissions in the Front Range. Future work includes comparison of isotopes and alkane ratios as tracers of methane sources, and calculation of total methane fluxes in the region using continuous measurements of methane concentrations during aircraft flights.

Source identification and trends in concentrations of gaseous and fine particulate principal species in Seoul, South Korea.

PubMed

Kang, Choong-Min; Kang, Byung-Wook; Lee, Hak Sung

2006-07-01

Ambient measurements were made using two sets of annular denuder system during the four seasons (April 2001 to February 2002) and were then compared with the results during the period of 1996-1997 to estimate the trends and seasonal variations in concentrations of gaseous and fine particulate matter (PM2.5) principal species. Annual averages of gaseous HNO3 and NH3 increased by 11% and 6%, respectively, compared with those of the previous study, whereas HONO and SO2 decreased by 11% and 136%, respectively. The PM2.5 concentration decreased by -17%, 35% for SO4(2-), and 29% for NH4+, whereas NO3- increased by 21%. Organic carbon (OC) and elemental carbon (EC) were 12.8 and 5.98 microg/m(-3), accounting for -26 and 12% of PM2.5 concentration, respectively. The species studied accounted for 84% of PM2.5 concentration, ranging from 76% in winter to 97% in summer. Potential source contribution function (PSCF) analysis was used to identify possible source areas affecting air pollution levels at a receptor site in Seoul. High possible source areas in concentrations of PM2.5, NO3-, SO4(2-), NH4+, and K+ were coastal cities of Liaoning province (possibly emissions from oil-fired boilers on ocean liners and fishing vessels and industrial emissions), inland areas of Heibei/Shandong provinces (the highest density areas of agricultural production and population) in China, and typical port cities (Mokpo, Yeosu, and Busan) of South Korea. In the PSCF map for OC, high possible source areas were also coastal cities of Liaoning province and inland areas of Heibei/Shandong provinces in China. In contrast, high possible source areas of EC were highlighted in the south of the Yellow Sea, indicating possible emissions from oil-fired boilers on large ships between South Korea and Southeast Asia. In summary, the PSCF results may suggest that air pollution levels in Seoul are affected considerably by long-range transport from external areas, such as the coastal zone in China and other cities in South Korea, as well as Seoul itself.

Estimating methane emissions from dairies in the Los Angeles Basin

NASA Astrophysics Data System (ADS)

Viatte, C.; Lauvaux, T.; Hedelius, J.; Parker, H. A.; Chen, J.; Jones, T.; Franklin, J.; Deng, A.; Gaudet, B.; Duren, R. M.; Verhulst, K. R.; Wunch, D.; Roehl, C. M.; Dubey, M. K.; Wofsy, S.; Wennberg, P. O.

2015-12-01

Inventory estimates of methane (CH4) emissions among the individual sources (mainly agriculture, energy production, and waste management) remain highly uncertain at regional and urban scales. Accurate atmospheric measurements can provide independent estimates to evaluate bottom-up inventories, especially in urban region, where many different CH4 sources are often confined in relatively small areas. Among these sources, livestock emissions, which are mainly originating from dairy cows, account for ~55% of the total CH4 emissions in California in 2013. This study aims to rigorously estimate the amount of CH4 emitted by the largest dairies in the Southern California region by combining measurements from four mobile ground-based spectrometers (EM27/SUN), in situ isotopic methane measurements from a CRDS analyzer (Picarro), and a high-resolution atmospheric transport model (the Weather Research and Forecasting model) in Large-Eddy Simulation mode. The remote sensing spectrometers measure the total column-averaged dry-air mole fractions of CH4 and CO2 (XCH4 and XCO2) in the near infrared region, providing information about total emissions of the dairies. Gradients measured by the four EM27 ranged from 0.2 to 22 ppb and from 0.7 to 3 ppm for XCH4 and XCO2, respectively. To assess the fluxes of the dairies, measurements of these gradients are used in conjunction with the local atmospheric dynamics simulated at 111 m resolution. Inverse modelling from WRF-LES is employed to resolve the spatial distribution of CH4 emissions in the domain. A Bayesian inversion and a Monte-Carlo approach were used to provide the CH4 emissions over the dairy with their associated uncertainties. The isotopic δ13C sampled at different locations in the area ranges from -40 ‰ to -55 ‰, indicating a mixture of anthropogenic and biogenic sources.

Diurnal and seasonal variation of various carbon fluxes from an urban tower platform in Houston, TX

NASA Astrophysics Data System (ADS)

Schade, G. W.; Werner, N.; Hale, M. C.

2013-12-01

We measured carbon fluxes (CO2, CO, VOCs) from a tall lattice tower in Houston between 2007 and 2009, and 2011-2013. We present results from various analyses of (i) anthropogenic and biogenic CO2 fluxes using a quadrant segregation technique, (ii) seasonal and multi-year changes of CO fluxes as related to car traffic and industrial sources, and (iii) the accuracy of, and usefulness of a bulk flux footprint model to quantify pentane emissions form a distant source in comparison to permitted emission levels. Segregated and net anthropogenic CO2 fluxes were dominated by car traffic but industrial sources were identified as well. Emissions sank to minimal levels after hurricane Ike had passed over Houston, causing a traffic shutdown and lower population density. Segregated biogenic fluxes showed a clear seasonal variation with photosynthetic activity between April and November, and large effects of the 2011 Texas drought due to negligible irrigation in the study area. Carbon monoxide fluxes, measured via a flux gradient technique, are even stronger dominated by car traffic than CO2 fluxes and serve as a traffic tracer. Our data show a continued drop in emissions over time, seasonal changes with higher emissions during winter, and local influences due to industrial emissions. Lastly, we present the results of a tracer release study and a single point source quantification to test a bulk footprint model in this complex urban area. Known releases of volatile acetone and MEK were compered to measured fluxes using a REA-GC-FID system, and permit emissions of pentane from a foam plastics manufacturing facility were compared to measured pentane fluxes. Both comparisons reveal a surprisingly accurate performance of the footprint model within a factor of 2.

Spatial patterns of mobile source particulate matter emissions-to-exposure relationships across the United States

NASA Astrophysics Data System (ADS)

Greco, Susan L.; Wilson, Andrew M.; Spengler, John D.; Levy, Jonathan I.

Assessing the public health benefits from air pollution control measures is assisted by understanding the relationship between mobile source emissions and subsequent fine particulate matter (PM 2.5) exposure. Since this relationship varies by location, we characterized its magnitude and geographic distribution using the intake fraction (iF) concept. We considered emissions of primary PM 2.5 as well as particle precursors SO 2 and NO x from each of 3080 counties in the US. We modeled the relationship between these emissions and total US population exposure to PM 2.5, making use of a source-receptor matrix developed for health risk assessment. For primary PM 2.5, we found a median iF of 1.2 per million, with a range of 0.12-25. Half of the total exposure was reached by a median distance of 150 km from the county where mobile source emissions originated, though this spatial extent varied across counties from within the county borders to 1800 km away. For secondary ammonium sulfate from SO 2 emissions, the median iF was 0.41 per million (range: 0.050-10), versus 0.068 per million for secondary ammonium nitrate from NO x emissions (range: 0.00092-1.3). The median distance to half of the total exposure was greater for secondary PM 2.5 (450 km for sulfate, 390 km for nitrate). Regression analyses using exhaustive population predictors explained much of the variation in primary PM 2.5 iF ( R2=0.83) as well as secondary sulfate and nitrate iF ( R2=0.74 and 0.60), with greater near-source contribution for primary than for secondary PM 2.5. We conclude that long-range dispersion models with coarse geographic resolution are appropriate for risk assessments of secondary PM 2.5 or primary PM 2.5 emitted from mobile sources in rural areas, but that more resolved dispersion models are warranted for primary PM 2.5 in urban areas due to the substantial contribution of near-source populations.

Multi-Sensor Constrained Time Varying Emissions Estimation of Black Carbon: Attributing Urban and Fire Sources Globally

NASA Astrophysics Data System (ADS)

Cohen, J. B.

2015-12-01

The short lifetime and heterogeneous distribution of Black Carbon (BC) in the atmosphere leads to complex impacts on radiative forcing, climate, and health, and complicates analysis of its atmospheric processing and emissions. Two recent papers have estimated the global and regional emissions of BC using advanced statistical and computational methods. One used a Kalman Filter, including data from AERONET, NOAA, and other ground-based sources, to estimate global emissions of 17.8+/-5.6 Tg BC/year (with the increase attributable to East Asia, South Asia, Southeast Asia, and Eastern Europe - all regions which have had rapid urban, industrial, and economic expansion). The second additionally used remotely sensed measurements from MISR and a variance maximizing technique, uniquely quantifying fire and urban sources in Southeast Asia, as well as their large year-to-year variability over the past 12 years, leading to increases from 10% to 150%. These new emissions products, when run through our state-of-the art modelling system of chemistry, physics, transport, removal, radiation, and climate, match 140 ground stations and satellites better in both an absolute and a temporal sense. New work now further includes trace species measurements from OMI, which are used with the variance maximizing technique to constrain the types of emissions sources. Furthermore, land-use change and fire estimation products from MODIS are also included, which provide other constraints on the temporal and spatial nature of the variations of intermittent sources like fires or new permanent sources like expanded urbanization. This talk will introduce a new, top-down constrained, weekly varying BC emissions dataset, show that it produces a better fit with observations, and draw conclusions about the sources and impacts from urbanization one hand, and fires on another hand. Results specific to the Southeast and East Asia will demonstrate inter- and intra-annual variations, such as the function of the wet and dry seasons. Further, the impacts of missing data due to cloud coverage and of long-range transport from highly polluted areas to relatively clean downwind areas will be demonstrated. More general results will also be discussed in relation to the global anthropogenic aerosol distribution.

Mobile mapping of methane emissions and isoscapes

NASA Astrophysics Data System (ADS)

Takriti, Mounir; Ward, Sue; Wynn, Peter; Elias, Dafydd; McNamara, Niall

2017-04-01

Methane (CH4) is a potent greenhouse gas emitted from a variety of natural and anthropogenic sources. It is crucial to accurately and efficiently detect CH4 emissions and identify their sources to improve our understanding of changing emission patterns as well as to identify ways to curtail their release into the atmosphere. However, using established methods this can be challenging as well as time and resource intensive due to the temporal and spatial heterogeneity of many sources. To address this problem, we have developed a vehicle mounted mobile system that combines high precision CH4 measurements with isotopic mapping and dual isotope source characterisation. We here present details of the development and testing of a unique system for the detection and isotopic analysis of CH4 plumes built around a Picarro isotopic (13C/12C) gas analyser and a high precision Los Gatos greenhouse gas analyser. Combined with micrometeorological measurements and a mechanism for collecting discrete samples for high precision dual isotope (13C/12C, 2H/1H) analysis the system enables mapping of concentrations as well as directional and isotope based source verification. We then present findings from our mobile methane surveys around the North West of England. This area includes a variety of natural and anthropogenic methane sources within a relatively small geographical area, including livestock farming, urban and industrial gas infrastructure, landfills and waste water treatment facilities, and wetlands. We show that the system was successfully able to locate leaks from natural gas infrastructure and emissions from agricultural activities and to distinguish isotope signatures from these sources.

Large area, surface discharge pumped, vacuum ultraviolet light source

DOEpatents

Sze, R.C.; Quigley, G.P.

1996-12-17

Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

Modelling urban δ13C variations in the Greater Toronto Area

NASA Astrophysics Data System (ADS)

Pugliese, S.; Vogel, F. R.; Murphy, J. G.; Worthy, D. E. J.; Zhang, J.; Zheng, Q.; Moran, M. D.

2015-12-01

Even in urbanized regions, carbon dioxide (CO2) emissions are derived from a variety of biogenic and anthropogenic sources and are influenced by atmospheric transport across borders. As policies are introduced to reduce the emission of CO2, there is a need for independent verification of emissions reporting. In this work, we aim to use carbon isotope (13CO2 and 12CO2) simulations in combination with atmospheric measurements to distinguish between CO2 sources in the Greater Toronto Area (GTA), Canada. This is being done by developing an urban δ13C framework based on existing CO2 emission data and forward modelling using a chemistry transport model, CHIMERE. The framework is designed to use region specific δ13C signatures of the dominant CO2 sources together with a CO2 inventory at a fine spatial and temporal resolution; the product is compared against highly accurate 13CO2 and 12CO2 ambient data. The strength of this framework is its potential to estimate both locally produced and regionally transported CO­2. Locally, anthropogenic CO­2 in urban areas is often derived from natural gas combustion (for heating) and gasoline/diesel combustion (for transportation); the isotopic signatures of these processes are significantly different (approximately d13CVPDB = -40 ‰ and -26 ‰ respectively) and can be used to infer their relative contributions. Furthermore, the contribution of transported CO2 can also be estimated as nearby regions often rely on other sources of heating (e.g. coal combustion), which has a very different signature (approximately d13CVPDB = -23 ‰). We present an analysis of the GTA in contrast to Paris, France where atmospheric observations are also available and 13CO2 has been studied. Utilizing our δ13C framework and differences in sectoral isotopic signatures, we quantify the relative contribution of CO2 sources on the overall measured concentration and assess the ability of this framework as a tool for tracing the evolution of sector-specific emissions.

Mathematical modeling of atmospheric fine particle-associated primary organic compound concentrations

NASA Astrophysics Data System (ADS)

Rogge, Wolfgang F.; Hildemann, Lynn M.; Mazurek, Monica A.; Cass, Glen R.; Simoneit, Bernd R. T.

1996-08-01

An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that are due to direct emissions from primary sources, confirming that these compounds are principally formed by atmospheric chemical reactions.

Global Partitioning of NOx Sources Using Satellite Observations: Relative Roles of Fossil Fuel Combustion, Biomass Burning and Soil Emissions

NASA Technical Reports Server (NTRS)

Jaegle, Lyatt; Steinberger, Linda; Martin, Randall V.; Chance, Kelly

2005-01-01

This document contains the following abstract for the paper "Global partitioning of NOx sources using satellite observations: Relative roles of fossil fuel combustion, biomass burning and soil emissions." Satellite observations have been used to provide important new information about emissions of nitrogen oxides. Nitrogen oxides (NOx) are significant in atmospheric chemistry, having a role in ozone air pollution, acid deposition and climate change. We know that human activities have led to a three- to six-fold increase in NOx emissions since pre-industrial times, and that there are three main surface sources of NOx: fuel combustion, large-scale fires, and microbial soil processes. How each of these sources contributes to the total NOx emissions is subject to some doubt, however. The problem is that current NOx emission inventories rely on bottom-up approaches, compiling large quantities of statistical information from diverse sources such as fuel and land use, agricultural data, and estimates of burned areas. This results in inherently large uncertainties. To overcome this, Lyatt Jaegle and colleagues from the University of Washington, USA, used new satellite observations from the Global Ozone Monitoring Experiment (GOME) instrument. As the spatial and seasonal distribution of each of the sources of NOx can be clearly mapped from space, the team could provide independent topdown constraints on the individual strengths of NOx sources, and thus help resolve discrepancies in existing inventories. Jaegle's analysis of the satellite observations, presented at the recent Faraday Discussion on "Atmospheric Chemistry", shows that fuel combustion dominates emissions at northern mid-latitudes, while fires are a significant source in the Tropics. Additionally, she discovered a larger than expected role for soil emissions, especially over agricultural regions with heavy fertilizer use. Additional information is included in the original extended abstract.

Nitrogen emissions, deposition, and monitoring in the western United States

Treesearch

Mark E. Fenn; Richard Haeuber; Gail S. Tonnesen; Jill S. Baron; Susanne Grossman-Clarke; Diane Hope; Daniel A. Jaffe; Scott Copeland; Linda Geiser; Heather M. Rueth; James O. Sickman

2003-01-01

Nitrogen (N) deposition in the western United States ranges from 1 to 4 kilograms (kg) per hectare (ha) per year over much of the region to as high as 30 to 90 kg per ha per year downwind of major urban and agricultural areas. Primary N emissions sources are transportation, agriculture, and industry. Emissions of N as ammonia are about 50% as great as emissions of N as...

Characterization of emissions sources in the California-Mexico Border Region during Cal-Mex 2010

NASA Astrophysics Data System (ADS)

Zavala, M. A.; Lei, W.; Li, G.; Bei, N.; Barrera, H.; Tejeda, D.; Molina, L. T.; Cal-Mex 2010 Emissions Team

2010-12-01

The California-Mexico border region provides an opportunity to evaluate the characteristics of the emission processes in rapidly expanding urban areas where intensive international trade and commerce activities occur. Intense anthropogenic activities, biomass burning, as well as biological and geological sources significantly contribute to high concentration levels of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitrogen oxides (NOx), volatile organic compounds (VOCs), air toxics, and ozone observed in the California-US Baja California-Mexico border region. The continued efforts by Mexico and US for improving and updating the emissions inventories in the sister cities of San Diego-Tijuana and Calexico-Mexicali has helped to understand the emission processes in the border region. In addition, the recent Cal-Mex 2010 field campaign included a series of measurements aimed at characterizing the emissions from major sources in the California-Mexico border region. In this work we will present our analyzes of the data obtained during Cal-Mex 2010 for the characterization of the emission sources and their use for the evaluation of the recent emissions inventories for the Mexican cities of Tijuana and Mexicali. The developed emissions inventories will be implemented in concurrent air quality modeling efforts for understanding the physical and chemical transformations of air pollutants in the California-Mexico border region and their impacts.

40 CFR 63.1191 - What notifications must I submit?

Code of Federal Regulations, 2010 CFR

2010-07-01

... types of sources are subject to the standard: (1) An area source that increases its emissions so that it becomes a major source. (2) A source that has an initial startup before the effective date of the standard. (3) A new or reconstructed source that has an initial startup after the effective date of the...

40 CFR 63.1191 - What notifications must I submit?

Code of Federal Regulations, 2014 CFR

2014-07-01

... types of sources are subject to the standard: (1) An area source that increases its emissions so that it becomes a major source. (2) A source that has an initial startup before the effective date of the standard. (3) A new or reconstructed source that has an initial startup after the effective date of the...

Methane Emissions from the Inland Waters of Alaska

NASA Astrophysics Data System (ADS)

Striegl, R. G.; Butman, D. E.; Stackpoole, S. M.; Dornblaser, M.

2017-12-01

Inland waters at high latitudes generally emit methane (CH4) continuously to the atmosphere during the open water season and build-up CH4 under ice during winter that is released over a short period following ice melt. Landscape position, stream and river size, water source, and turbulence created by water flow largely control CH4 emissions from streams and rivers. Organic carbon sources for CH4 production in lakes vary widely among lakes and landscapes and include hydrologic inputs from terrestrial sources, releases from permafrost thaw (thermokarst), and autochthonous inputs from aquatic macrophytes and algae. Lake emissions are therefore controlled by the balance between within-lake CH4 production and consumption, surface turbulence at the water-air interface, and CH4 ebullition. This creates a complex range of conditions that are difficult to characterize, where dissolved CH4 concentrations may vary by up to 4 orders of magnitude among lakes and/or within a single lake over an annual seasonal cycle. Moreover, large inputs of organic matter from permafrost thaw or other sources commonly result in high rates of bubble production and ebullition from some lakes, while other lakes have negligible ebullition. We quantified water surface areas and estimated CH4 emission rates for lakes, streams and rivers for the six major hydrologic regions of Alaska and determined that they collectively emit about 0.124 Tg C per year as CH4 to the atmosphere. Lake emissions comprise about 75% of the total. When adjusted for total land surface area in Alaska, our lake emission estimate is substantially smaller than previous global estimates for inland waters north of 50 degrees North latitude. We attribute this to incorporation of results that cover a broad range of lake conditions in interior Alaska and to new data from lakes in southwest Alaska that have very low CH4 concentration but very large surface area.

Source origin of trace elements in PM from regional background, urban and industrial sites of Spain

NASA Astrophysics Data System (ADS)

Querol, X.; Viana, M.; Alastuey, A.; Amato, F.; Moreno, T.; Castillo, S.; Pey, J.; de la Rosa, J.; Sánchez de la Campa, A.; Artíñano, B.; Salvador, P.; García Dos Santos, S.; Fernández-Patier, R.; Moreno-Grau, S.; Negral, L.; Minguillón, M. C.; Monfort, E.; Gil, J. I.; Inza, A.; Ortega, L. A.; Santamaría, J. M.; Zabalza, J.

Despite their significant role in source apportionment analysis, studies dedicated to the identification of tracer elements of emission sources of atmospheric particulate matter based on air quality data are relatively scarce. The studies describing tracer elements of specific sources currently available in the literature mostly focus on emissions from traffic or large-scale combustion processes (e.g. power plants), but not on specific industrial processes. Furthermore, marker elements are not usually determined at receptor sites, but during emission. In our study, trace element concentrations in PM 10 and PM 2.5 were determined at 33 monitoring stations in Spain throughout the period 1995-2006. Industrial emissions from different forms of metallurgy (steel, stainless steel, copper, zinc), ceramic and petrochemical industries were evaluated. Results obtained at sites with no significant industrial development allowed us to define usual concentration ranges for a number of trace elements in rural and urban background environments. At industrial and traffic hotspots, average trace metal concentrations were highest, exceeding rural background levels by even one order of magnitude in the cases of Cr, Mn, Cu, Zn, As, Sn, W, V, Ni, Cs and Pb. Steel production emissions were linked to high levels of Cr, Mn, Ni, Zn, Mo, Cd, Se and Sn (and probably Pb). Copper metallurgy areas showed high levels of As, Bi, Ga and Cu. Zinc metallurgy was characterised by high levels of Zn and Cd. Glazed ceramic production areas were linked to high levels of Zn, As, Se, Zr, Cs, Tl, Li, Co and Pb. High levels of Ni and V (in association) were tracers of petrochemical plants and/or fuel-oil combustion. At one site under the influence of heavy vessel traffic these elements could be considered tracers (although not exclusively) of shipping emissions. Levels of Zn-Ba and Cu-Sb were relatively high in urban areas when compared with industrialised regions due to tyre and brake abrasion, respectively.

A tuneable approach to uniform light distribution for artificial daylight photodynamic therapy.

PubMed

O'Mahoney, Paul; Haigh, Neil; Wood, Kenny; Brown, C Tom A; Ibbotson, Sally; Eadie, Ewan

2018-06-16

Implementation of daylight photodynamic therapy (dPDT) is somewhat limited by variable weather conditions. Light sources have been employed to provide artificial dPDT indoors, with low irradiances and longer treatment times. Uniform light distribution across the target area is key to ensuring effective treatment, particularly for large areas. A novel light source is developed with tuneable direction of light emission in order to meet this challenge. Wavelength composition of the novel light source is controlled such that the protoporphyrin-IX (PpIX) weighed spectra of both the light source and daylight match. The uniformity of the light source is characterised on a flat surface, a model head and a model leg. For context, a typical conventional PDT light source is also characterised. Additionally, the wavelength uniformity across the treatment site is characterised. The PpIX-weighted spectrum of the novel light source matches with PpIX-weighted daylight spectrum, with irradiance values within the bounds for effective dPDT. By tuning the direction of light emission, improvements are seen in the uniformity across large anatomical surfaces. Wavelength uniformity is discussed. We have developed a light source that addresses the challenges in uniform, multiwavelength light distribution for large area artificial dPDT across curved anatomical surfaces. Copyright © 2018. Published by Elsevier B.V.

Pasture-scale methane emissions of grazing cattle

USDA-ARS?s Scientific Manuscript database

Grazing cattle are mobile point sources of methane and present challenges to quantify emissions using noninterfering micrometeorological methods. Stocking density is low and cattle can bunch up or disperse over a wide area, so knowing cattle locations is critical. The methane concentration downwind ...

EVALUATION OF FUGITIVE EMISSIONS USING GROUND-BASED OPTICAL REMOTE SENSING TECHNOLOGY

EPA Science Inventory

EPA has developed and evaluated a method for characterizing fugitive emissions from large area sources. The method, known as radial plume mapping (RPM) uses multiple-beam, scanning, optical remote sensing (ORS) instrumentation such as open-path Fourier transform infrared spectro...

Nitrogen isotopes as indicators of NOx source contributions to atmospheric nitrate deposition across the midwestern and northeastern United States

USGS Publications Warehouse

Elliott, E.M.; Kendall, C.; Wankel, Scott D.; Burns, Douglas A.; Boyer, E.W.; Harlin, K.; Bain, D.J.; Butler, T.J.

2007-01-01

Global inputs of NOx are dominated by fossil fuel combustion from both stationary and vehicular sources and far exceed natural NOx sources. However, elucidating NOx sources to any given location remains a difficult challenge, despite the need for this information to develop sound regulatory and mitigation strategies. We present results from a regional-scale study of nitrogen isotopes (??15N) in wet nitrate deposition across 33 sites in the midwestern and northeastern U.S. We demonstrate that spatial variations in ??15N are strongly correlated with NOx emissions from surrounding stationary sources and additionally that ??15N is more strongly correlated with surrounding stationary source NOx emissions than pH, SO 42-, or NO3- concentrations. Although emission inventories indicate that vehicle emissions are the dominant NOx source in the eastern U.S., our results suggest that wet NO 3- deposition at sites in this study is strongly associated with NOx emissions from stationary sources. This suggests that large areas of the landscape potentially receive atmospheric NOy deposition inputs in excess of what one would infer from existing monitoring data alone. Moreover, we determined that spatial patterns in ??15N values are a robust indicator of stationary NOx contributions to wet NO3- deposition and hence a valuable complement to existing tools for assessing relationships between NO 3- deposition, regional emission inventories, and for evaluating progress toward NOx reduction goals. ?? 2007 American Chemical Society.

77 FR 11974 - Approval and Promulgation of Implementation Plans; State of Iowa Regional Haze State...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-28

... and beyond. The modeling was based on PM Source Apportionment Technology (PSAT) for the Comprehensive... sources and the State adequately determined the apportionment of those pollutants from sources located... Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic...

Methods for Characterizing the Distribution of Exhaust Emissions from Light-Duty, Gasoline-Powered Motor Vehicles in the U.S. Fleet

EPA Science Inventory

Mobile sources significantly contribute to ambient concentrations of airborne particulate matter. Source apportionment studies for PMlO and PM2.5 indicate that mobile sources can be responsible for over half of the ambient PM measured in an urban area. Recent source apportionment...

A New Global Open Source Marine Hydrocarbon Emission Site Database

NASA Astrophysics Data System (ADS)

Onyia, E., Jr.; Wood, W. T.; Barnard, A.; Dada, T.; Qazzaz, M.; Lee, T. R.; Herrera, E.; Sager, W.

2017-12-01

Hydrocarbon emission sites (e.g. seeps) discharge large volumes of fluids and gases into the oceans that are not only important for biogeochemical budgets, but also support abundant chemosynthetic communities. Documenting the locations of modern emissions is a first step towards understanding and monitoring how they affect the global state of the seafloor and oceans. Currently, no global open source (i.e. non-proprietry) detailed maps of emissions sites are available. As a solution, we have created a database that is housed within an Excel spreadsheet and use the latest versions of Earthpoint and Google Earth for position coordinate conversions and data mapping, respectively. To date, approximately 1,000 data points have been collected from referenceable sources across the globe, and we are continualy expanding the dataset. Due to the variety of spatial extents encountered, to identify each site we used two different methods: 1) point (x, y, z) locations for individual sites and; 2) delineation of areas where sites are clustered. Certain well-known areas, such as the Gulf of Mexico and the Mediterranean Sea, have a greater abundance of information; whereas significantly less information is available in other regions due to the absence of emission sites, lack of data, or because the existing data is proprietary. Although the geographical extent of the data is currently restricted to regions where the most data is publicly available, as the database matures, we expect to have more complete coverage of the world's oceans. This database is an information resource that consolidates and organizes the existing literature on hydrocarbons released into the marine environment, thereby providing a comprehensive reference for future work. We expect that the availability of seafloor hydrocarbon emission maps will benefit scientific understanding of hydrocarbon rich areas as well as potentially aiding hydrocarbon exploration and environmental impact assessements.

CH4 emissions from European Major Population Centers: Results from aircraft-borne CH4 in-situ observations during EMeRGe-Europe campaign 2017

NASA Astrophysics Data System (ADS)

Roiger, A.; Klausner, T.; Schlager, H.; Ziereis, H.; Huntrieser, H.; Baumann, R.; Eirenschmalz, L.; Joeckel, P.; Mertens, M.; Fisher, R.; Bauguitte, S.; Young, S.; Andrés Hernández, M. D.

2017-12-01

Urban environments represent large and diffuse area sources of CH4 including emissions from pipeline leaks, industrial/sewage treatment plants, and landfills. However, there is little knowledge about the exact magnitude of these emissions and their contribution to total anthropogenic CH4. Especially in the context of an urbanizing world, a better understanding of the methane footprint of urban areas is crucial, both with respect to mitigation and projection of climate impacts. Aircraft-borne in-situ measurements are particularly useful to both quantify emissions from such area sources, as well as to study their impact on the regional distribution. However, airborne CH4 observations downstream of European cities are especially sparse.Here we report from aircraft-borne CH4 in-situ measurements as conducted during the HALO aircraft campaign EMeRGe (Effect of Megacities on the Transport and Transformation of Pollutants on the Regional to Global Scales) in July 2017, which was led by the University of Bremen, Germany. During seven research flights, emissions from a variety of European (Mega)-cities were probed at different altitudes from 3km down to 500m, including measurements in the outflows of London, Rome, Po Valley, Ruhr and Benelux. We will present and compare the CH4 distribution measured downstream of the various studied urban hot-spots. With the help of other trace gas measurements (including e.g. CO2, CO, O3, SO2), observed methane enhancements will be attributed to the different potential source types. Finally, by the combination of in-situ measurements and regional model simulations using the EMAC-MECO(n) model, the contribution of emissions from urban centers to the regional methane budget over Europe will be discussed.

Arrays of Bundles of Carbon Nanotubes as Field Emitters

NASA Technical Reports Server (NTRS)

Manohara, Harish; Bronkowski, Michael

2007-01-01

Experiments have shown that with suitable choices of critical dimensions, planar arrays of bundles of carbon nanotubes (see figure) can serve as high-current-density field emitter (cold-cathode) electron sources. Whereas some hot-cathode electron sources must be operated at supply potentials of thousands of volts, these cold-cathode sources generate comparable current densities when operated at tens of volts. Consequently, arrays of bundles of carbon nanotubes might prove useful as cold-cathode sources in miniature, lightweight electron-beam devices (e.g., nanoklystrons) soon to be developed. Prior to the experiments, all reported efforts to develop carbon-nanotube-based field-emission sources had yielded low current densities from a few hundred microamperes to a few hundred milliamperes per square centimeter. An electrostatic screening effect, in which taller nanotubes screen the shorter ones from participating in field emission, was conjectured to be what restricts the emission of electrons to such low levels. It was further conjectured that the screening effect could be reduced and thus emission levels increased by increasing the spacing between nanotubes to at least by a factor of one to two times the height of the nanotubes. While this change might increase the emission from individual nanotubes, it would decrease the number of nanotubes per unit area and thereby reduce the total possible emission current. Therefore, to maximize the area-averaged current density, it would be necessary to find an optimum combination of nanotube spacing and nanotube height. The present concept of using an array of bundles of nanotubes arises partly from the concept of optimizing the spacing and height of field emitters. It also arises partly from the idea that single nanotubes may have short lifetimes as field emitters, whereas bundles of nanotubes could afford redundancy so that the loss of a single nanotube would not significantly reduce the overall field emission.

Evaluating emissions of HCHO, HONO, NO2, and SO2 from point sources using portable Imaging DOAS

NASA Astrophysics Data System (ADS)

Pikelnaya, O.; Tsai, C.; Herndon, S. C.; Wood, E. C.; Fu, D.; Lefer, B. L.; Flynn, J. H.; Stutz, J.

2011-12-01

Our ability to quantitatively describe urban air pollution to a large extent depends on an accurate understanding of anthropogenic emissions. In areas with a high density of individual point sources of pollution, such as petrochemical facilities with multiple flares or regions with active commercial ship traffic, this is particularly challenging as access to facilities and ships is often restricted. Direct formaldehyde emissions from flares may play an important role for ozone chemistry, acting as an initial radical precursor and enhancing the degradation of co-emitted hydrocarbons. HONO is also recognized as an important OH source throughout the day. However, very little is known about direct HCHO and HONO emissions. Imaging Differential Optical Absorption Spectroscopy (I-DOAS), a relatively new remote sensing technique, provides an opportunity to investigate emissions from these sources from a distance, making this technique attractive for fence-line monitoring. In this presentation, we will describe I-DOAS measurements during the FLAIR campaign in the spring/summer of 2009. We performed measurements outside of various industrial facilities in the larger Houston area as well as in the Houston Ship Channel to visualize and quantify the emissions of HCHO, NO2, HONO, and SO2 from flares of petrochemical facilities and ship smoke stacks. We will present the column density images of pollutant plumes as well as fluxes from individual flares calculated from I-DOAS observations. Fluxes from individual flares and smoke stacks determined from the I-DOAS measurements vary widely in time and by the emission sources. We will also present HONO/NOx ratios in ship smoke stacks derived from the combination of I-DOAS and in-situ measurements, and discuss other trace gas ratios in plumes derived from the I-DOAS observations. Finally, we will show images of HCHO, NO2 and SO2 plumes from control burn forest fires observed in November of 2009 at Vandenberg Air Force Base, Santa Maria, CA.

Atmospheric toxic metals emission inventory and spatial characteristics from anthropogenic sources of Guangdong province, China

NASA Astrophysics Data System (ADS)

Cher, S.; Menghua, L.; Xiao, X.; Yuqi, W.; Zhuangmin, Z.; Zhijiong, H.; Cheng, L.; Guanglin, J.; Zibing, Y.; Junyu, Z.

2017-12-01

Atmospheric toxic metals (TMs) are part of particulate matters, and may create adverse effects on the environment and human health depending upon their bioavailability and toxicity. Localized emission inventory is fundamental for parsing of toxic metals to identify key sources in order to formulate efficient toxic metals control strategies. With the use of the latest municipal level environment statistical data, this study developed a bottom-up emission inventory of five toxic metals (Hg, As, Pb, Cd, Cr) from anthropogenic activities in Guangdong province for the year of 2014. Major atmospheric toxic metals sources including combustion sources (coal, oil, biomass, municipal solid waste) and industrial process sources (cement production, nonferrous metal smelting, iron and steel industry, battery and fluorescent lamp production) were investigated. Results showed that: (1) The total emissions of Hg, As, Pb, Cd, Cr in Guangdong province were 18.14, 32.59, 411.34, 13.13, 84.16 t, respectively. (2) Different pollutants have obvious characteristics of emission sources. For total Hg emission, 46% comes from combustion sources, of which 32% from coal combustion and 8% from MSW combustion. Other 54% comes from industrial processes, which dominated by the cement (19%), fluorescent lamp (18%) and battery production (13%). Of the total Hg emission, 69% is released as Hg0 , 29% as Hg2+ , and only 2% as Hgp due to strict particulate matters controls policies. For As emissions, coal combustion, nonferrous metal smelting and iron and steel industry contributed approximate 48%, 25% and 24%, respectively. Pb emissions primarily come from battery production (42%), iron and steel industry (21%) and on-road mobile gasoline combustion (17%). Cd and Cr emissions were dominated by nonferrous metal smelting (71%) and iron and steel industry (82%), respectively. (3) In term of the spatial distribution, emissions of atmospheric toxic metals are mainly concentrated in the central region of the Pearl River Delta, such as, Guangzhou, Dongguan, and Foshan et.al. These areas were characterized with large amounts of coal combustion, battery production and fluorescent production. With the implementation of ultra-low emission standards in coal-fired power plant, TMs emissions from industrial process sources should be emphasized.

Inverse modeling and mapping US air quality influences of inorganic PM2.5 precursor emissions using the adjoint of GEOS-Chem

NASA Astrophysics Data System (ADS)

Henze, D. K.; Seinfeld, J. H.; Shindell, D. T.

2009-08-01

Influences of specific sources of inorganic PM2.5 on peak and ambient aerosol concentrations in the US are evaluated using a combination of inverse modeling and sensitivity analysis. First, sulfate and nitrate aerosol measurements from the IMPROVE network are assimilated using the four-dimensional variational (4D-Var) method into the GEOS-Chem chemical transport model in order to constrain emissions estimates in four separate month-long inversions (one per season). Of the precursor emissions, these observations primarily constrain ammonia (NH3). While the net result is a decrease in estimated US~NH3 emissions relative to the original inventory, there is considerable variability in adjustments made to NH3 emissions in different locations, seasons and source sectors, such as focused decreases in the midwest during July, broad decreases throughout the US~in January, increases in eastern coastal areas in April, and an effective redistribution of emissions from natural to anthropogenic sources. Implementing these constrained emissions, the adjoint model is applied to quantify the influences of emissions on representative PM2.5 air quality metrics within the US. The resulting sensitivity maps display a wide range of spatial, sectoral and seasonal variability in the susceptibility of the air quality metrics to absolute emissions changes and the effectiveness of incremental emissions controls of specific source sectors. NH3 emissions near sources of sulfur oxides (SOx) are estimated to most influence peak inorganic PM2.5 levels in the East; thus, the most effective controls of NH3 emissions are often disjoint from locations of peak NH3 emissions. Controls of emissions from industrial sectors of SOx and NOx are estimated to be more effective than surface emissions, and changes to NH3 emissions in regions dominated by natural sources are disproportionately more effective than regions dominated by anthropogenic sources. NOx controls are most effective in northern states in October; in January, SOx controls may be counterproductive. When considering ambient inorganic PM2.5 concentrations, intercontinental influences are small, though transboundary influences within North America are significant, with SOx emissions from surface sources in Mexico contributing almost a fourth of the total influence from this sector.

Inverse modeling and mapping US air quality influences of inorganic PM2.5 precursor emissions using the adjoint of GEOS-Chem

NASA Astrophysics Data System (ADS)

Henze, D. K.; Seinfeld, J. H.; Shindell, D. T.

2008-08-01

Influences of specific sources of inorganic PM2.5 on peak and ambient aerosol concentrations in the US are evaluated using a combination of inverse modeling and sensitivity analysis. First, sulfate and nitrate aerosol measurements from the IMPROVE network are assimilated using the four-dimensional variational (4D-Var) method into the GEOS-Chem chemical transport model in order to constrain emissions estimates in four separate month-long inversions (one per season). Of the precursor emissions, these observations primarily constrain ammonia (NH3). While the net result is a decrease in estimated US NH3 emissions relative to the original inventory, there is considerable variability in adjustments made to NH3 emissions in different locations, seasons and source sectors, such as focused decreases in the midwest during July, broad decreases throughout the US~in January, increases in eastern coastal areas in April, and an effective redistribution of emissions from natural to anthropogenic sources. Implementing these constrained emissions, the adjoint model is applied to quantify the influences of emissions on representative PM2.5 air quality metrics within the US. The resulting sensitivity maps display a wide range of spatial, sectoral and seasonal variability in the susceptibility of the air quality metrics to absolute emissions changes and the effectiveness of incremental emissions controls of specific source sectors. NH3 emissions near sources of sulfur oxides (SOx) are estimated to most influence peak inorganic PM2.5 levels in the East; thus, the most effective controls of NH3 emissions are often disjoint from locations of peak NH3 emissions. Controls of emissions from industrial sectors of SOx and NOx are estimated to be more effective than surface emissions, and changes to NH3 emissions in regions dominated by natural sources are disproportionately more effective than regions dominated by anthropogenic sources. NOx controls are most effective in northern states in October; in January, SOx controls may be counterproductive. When considering ambient inorganic PM2.5 concentrations, intercontinental influences are small, though transboundary influences within North America are significant, with SOx emissions from surface sources in Mexico contributing almost a fourth of the total influence from this sector.

Modelling Southern Africa Air Quality and Atmosphere: Importance and Interplay of Natural and Anthropogenic Emissions

NASA Astrophysics Data System (ADS)

Garland, R. M.; Naidoo, M.; Dedekind, Z.; Sibiya, B.; Piketh, S.; Engelbrecht, C. J.; Engelbrecht, F.

2017-12-01

Many parts of the southern hemisphere are linked in part due to the strong impact that emissions from natural sources, such as large biomass burning events and marine sources, as well as growing anthropogenic emission sources. Most of southern Africa has an arid to semi-arid climate that is strongly impacted by biomass burning, biogenic and dust emissions. In addition, there are areas of growing industrialization and urbanization that contributes to poor air quality. This air pollution can impact not only human health, but also agriculture, ecosystems, and the climate. This presentation will highlight on-going research to simulate the southern Africa atmosphere and impacts, with a focus on the interplay and relative importance of natural and anthropogenic emissions. The presentation will discuss the simulated sensitivity of the southern African climate to aerosol particles to highlight the importance of natural sources. These historical simulations (1979-2012) were performed with CCAM and are towards the development of the first Africa-led earth systems model. The analysis focused on the simulated sensitivity of the climate and clouds off the southwestern coast of Africa to aerosol particles. The interplay between natural and anthropogenic sources on air pollution will be highlighted using the Waterberg region of South Africa as a case study. CAMx was run at 2km resolution for 2013 using local emission inventories and meteorological output from CCAM to simulate the air quality of the region. These simulations estimate that, on average in the summer, up to 20% of ozone in and around a power plant plume is attributable to biogenic sources of VOCs, with ozone peaks of up to 120ppb; highlighting the importance of understanding the mix of pollutants in this area. In addition to presenting results from this study, the challenges in modelling will be highlighted. These challenges include very few or no measurements that are important to understand, and then accurately simulate, atmospheric chemistry (e.g. OH, PAN, SOA).

75 FR 32682 - National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-09

... for Existing Sources: Commercial and Industrial Solid Waste Incineration Units; Identification of Non-Hazardous Secondary Materials That Are Solid Waste AGENCY: Environmental Protection Agency. ACTION: Notice... Institutional Boilers located at area sources; and Commercial and Industrial Solid Waste Incineration Units. On...

Air quality assessment of Estarreja, an urban industrialized area, in a coastal region of Portugal.

PubMed

Figueiredo, M L; Monteiro, A; Lopes, M; Ferreira, J; Borrego, C

2013-07-01

Despite the increasing concern given to air quality in urban and industrial areas in recent years, particular emphasis on regulation, control, and reduction of air pollutant emissions is still necessary to fully characterize the chain emissions-air quality-exposure-dose-health effects, for specific sources. The Estarreja region was selected as a case study because it has one of the largest chemical industrial complexes in Portugal that has been recently expanded, together with a growing urban area with an interesting location in the Portuguese coastland and crossed by important road traffic and rail national networks. This work presents the first air quality assessment for the region concerning pollutant emissions and meteorological and air quality monitoring data analysis, over the period 2000-2009. This assessment also includes a detailed investigation and characterization of past air pollution episodes for the most problematic pollutants: ozone and PM10. The contribution of different emission sources and meteorological conditions to these episodes is investigated. The stagnant meteorological conditions associated with local emissions, namely industrial activity and road traffic, are the major contributors to the air quality degradation over the study region. A set of measures to improve air quality--regarding ozone and PM10 levels--is proposed as an air quality management strategy for the study region.

Use of lichen fumigation studies to evaluate the effects of new emission sources on class I areas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, R.; Webb, P.G.; Biggs, R.H.

1988-02-01

Allowable increments of SO/sub 2/ from new emission sources near Class I areas are severely limited by the PSD provisions of the Clean Air Act, unless the applicant can prove that the expected emissions will not adversely affect the air quality related values of Class I area. Lichens are considered to be the resource that is most sensitive to SO/sub 2/. If projected concentrations will not injure lichens, other resources should not be affected. Four lichen species native to two Class I area, Cape Romain National Wildlife Refuge and Everglades National Park, were fumigated in the laboratory with SO/sub 2/more » doses that simulated the frequencies, duration, and concentrations expected from potential new sources. Lichens from Cape Romain were fumigated with 240 ..mu..g/m/sup 3/, 400 ..mu..g/m/sup 3/, and ambient air 3 hours/week for 6 weeks. No differences in biomass gain, percent electrolyte leakage in solution (an indicator of membrane damage) or /sup 14/CO/sub 2/ assimilation were observed among treatments. Lichens from Everglades National Park were fumigated with 100 ..mu..g/m/sup 3/, 200 ..mu..g/m/sup 3/, 400 ..mu..g/m/sup 3/, and ambient air 6 hours/week for 10 weeks. Percent electrolyte leakage of Parmotrema tinctorum was greater at the two high concentrations, but there was no significant effect on biomass gain or /sup 14/CO/sub 2/ assimilation. Percent electrolyte leakage increased and biomass gain and /sup 14/CO/sub 2/ assimilation decreased in Ramalina denticulata at 400 ..mu..g/m/sup 3/ SO/sub 2/ in comparison with lower concentrations. Studies of fumigation effects on lichens are a useful technique for the evaluation of impacts of emission sources on air quality related values in Class I areas.« less

Emissions from vehicles, tailpipe and vehicle re-entrained road dust

NASA Astrophysics Data System (ADS)

Zhu, Dongzi

Emissions from transportation are some of the largest sources of urban air pollution. Transportation emissions originate from both the engine-through combustion processes and non-tailpipe re-suspended road dust emissions induced by vehicle travel on unpaved and paved roads. Gaseous and particulate emissions from transportation sources have negative impacts on human health, visibility and may influence the global radiation balance. Fugitive dust emissions originating from vehicle travel on paved and unpaved roads constitute a significant fraction of the PM10 in many areas of the western US impacting their attainment status of National Ambient Air Quality Standards. The research used three novel instrument platforms developed at the Desert Research Institute. The In-Plume Emissions Test Stand (IPETS) was designed to provide characterization of exhaust emissions from in-use individual vehicles or engines by analyzing air as close as 1 m from the exhaust port. Real-world emission factors can be quantified by in-plume measurements and provide more realistic measures for emission inventories, source modeling, and receptor modeling than certification measurements. The Testing Re-entrained Aerosol Kinetic Emissions from Roads (TRAKER) provides an effective alternate approach to the EPA AP-42 road dust emissions estimation techniques by sampling 1000s of km of roads versus isolated 3 m sections. The Portable Deposition Monitoring Platform (PDMP incorporates PM and meteorological instruments to characterize the downwind change in particle concentrations to define depositional losses in different environments. The research outcome provides important knowledge for understanding diesel engine emissions, road dust emissions and aerosol deposition process near road sources.

40 CFR 63.6603 - What emission limitations and operating limitations must I meet if I own or operate an existing...

Code of Federal Regulations, 2010 CFR

2010-07-01

... operating limitations must I meet if I own or operate an existing stationary CI RICE located at an area... and operating limitations must I meet if I own or operate an existing stationary CI RICE located at an... stationary CI RICE located at an area source of HAP emissions, you must comply with the requirements in Table...

An integrated system for the determination of the local, regional and long-transport contributions to Particulate Matter concentrations

NASA Astrophysics Data System (ADS)

Amodio, M.; Andriani, E.; Daresta, B. E.; de Gennaro, G.; di Gilio, A.; Ielpo, P.,; Placentino, C. M.; Trizio, L.; Tutino, M.

2010-05-01

Several epidemiological studies have shown the negative effects of air pollution on human health, which range from respiratory and cardiovascular disease to neurotoxic effects, and cancer. Most recent investigations have been focused on health toxicological features of Particulate Matter (PM) and its interactions with other pollutants: it was found that fine particles (PM2.5) could be an effective media to transport these pollutants deeply into the lung and to cause many kind of reactions which include oxidative stress, local pulmonary and systemic inflammatory responses (Künzli and Perez, 2009). Based on these implications on public health, many countries have developed plans to suggest effective control strategies which involve the identification of Particulate Matter sources, the quantitative estimation of the emission rates of the pollutants, the understanding of PM transport, mixing and transformation processes and the identification of main factors influencing PM concentrations. In this field, receptor models can be useful tools to estimate sources contributions to PM collected in an area under investigations. Different approaches to receptor model analysis can be distinguished on basis of whether chemical characteristics of emission sources are required to be known before the source apportionment. The multivariate approach could be preferred when a lack of information concerning sources profiles occurred (Hopke, 2003). In this work, the results obtained by applying an integrated approach in the monitoring of PM using several typologies of instrumentations will be shown. A prototype for the determination of the contributions of a single source (‘fugitive emission') on the fine PM concentrations has been developed: it consists of a Swam dual-channel sampler, an OPC Monitor, a sonic anemometer and a PBL Mixing monitor. The investigated site chosen for the application of prototype will be the iron and steel pole of Taranto (Apulia Region, South of Italy). Fugitive emission campaign will be performed by using three different positions around the Taranto industrial area; the main interest on Taranto is due to the presence of several activities of high impact as very wide industrial area close to the town and the numerous maritime and military activities in the harbour area (Amodio et al., 2008). The aim is to triangulate the area of the examined source on the basis of the prevalent directions of the wind. The investigation will be completed by chemical-physical characterization of PM2.5 and PM10 samples collected by the prototype in order to have additional information about the possible emissive sources. The statistical analysis, performed by Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF), will be used for a detailed study of the impact of the local emissive source on the neighboring areas. Finally, the prototype will allow to identify and distinguish long range transport, regional and other local contributions on the fine PM concentrations. This work was supported by the Strategic Project PS_122 founded by Apulia Region. References Künzli, N., Perez, L., 2009. Swiss Medical Weekly 139(17-18), 242-250. Hopke, P.K., 2003. Journal of Chemometrics 17(5), 255-265. Amodio, M., Caselli, M., Daresta, B.E., de Gennaro, G., Ielpo, P., Placentino, C.M., Tutino, 2008. Chemical Engineering Transactions 16, 193-199.

The vertical and horizontal chemical inhomogeneity over the planetary boundary layer of the Seoul Metropolitan Area

NASA Astrophysics Data System (ADS)

Kim, S.; Guenther, A. B.; Seco, R.; Gu, D.; Jeong, D.; Sanchez, D.; Brune, W. H.; Blake, D. R.; Armin, W.; Ahn, J. Y.; Lee, Y.; Kim, D.; Shin, H.; Jung, J.; Kim, D. S.; Lee, M.; Lee, G.

2017-12-01

During the KORUS-AQ field campaign in 2016, various platforms were utilized to characterize emission, chemical transformation, and removal of trace gases and fine particles. One may consider that the Seoul Metropolitan Area, where was the main study area, is a relatively small metropolitan in physical size wise but it is an extremely dense metropolitan area with various anthropogenic and natural emission sources. Therefore, the comprehensive understanding of various emission sources and complicated photochemistry within the boundary layer of the megacity should be preceded to precisely evaluate the impacts of megacity to global air quality and climate. In this context, we will present a detailed analysis of trace gas distributions over the Seoul Metropolitan Area. The focus will be a dataset collected at the Taehwa Research Forest, a downwind forest for fresh and aged pollution plumes. The trace gas reactivity also known as OH reactivity will be presented by comparing with a city center research site-the Olympic Park supersite. The DC-8 aircraft dataset will be presented to examine the evolution of anthropogenic pollution and the amplification of photochemistry from biogenic volatile organic compound emissions. Eventually, we expect that the three dimensional analysis of the distributions of atmospheric reactivity will provide an important snapshot on a complex nature of trace gas distribution in the Megacity planetary boundary layer.

Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region

NASA Astrophysics Data System (ADS)

Parrish, D. D.; Ryerson, T. B.; Mellqvist, J.; Johansson, J.; Fried, A.; Richter, D.; Walega, J. G.; Washenfelder, R. A.; de Gouw, J. A.; Peischl, J.; Aikin, K. C.; McKeen, S. A.; Frost, G. J.; Fehsenfeld, F. C.; Herndon, S. C.

2011-12-01

We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 ± 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 ± 2%), and secondary production (~3%) and primary emissions (~1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We have not addressed other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.

Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region

NASA Astrophysics Data System (ADS)

Parrish, D. D.; Ryerson, T. B.; Mellqvist, J.; Johansson, J.; Fried, A.; Richter, D.; Walega, J. G.; Washenfelder, R. A.; de Gouw, J. A.; Peischl, J.; Aikin, K. C.; McKeen, S. A.; Frost, G. J.; Fehsenfeld, F. C.; Herndon, S. C.

2012-04-01

We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 ± 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 ± 2%), and secondary production (~3%) and primary emissions (~1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We do not address other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.

Fugitive coke oven gas emission profile by continuous line averaged open-path Fourier transform infrared monitoring.

PubMed

Lin, Chitsan; Liou, Naiwei; Chang, Pao-Erh; Yang, Jen-Chin; Sun, Endy

2007-04-01

Although most coke oven research is focused on the emission of polycyclic aromatic hydrocarbons, well-known carcinogens, little has been done on the emission of volatile organic compounds, some of which are also thought to be hazardous to workers and the environment. To profile coke oven gas (COG) emissions, we set up an open-path Fourier transform infrared (OP-FTIR) system on top of a battery of coke ovens at a steel mill located in Southern Taiwan and monitored average emissions in a coke processing area for 16.5 hr. Nine COGs were identified, including ammonia, CO, methane, ethane, ethylene, acetylene, propylene, cyclohexane, and O-xylene. Time series plots indicated that the type of pollutants differed over time, suggesting that different emission sources (e.g., coke pushing, quench tower, etc.) were involved at different times over the study period. This observation was confirmed by the low cross-correlation coefficients of the COGs. It was also found that, with the help of meteorological analysis, the data collected by the OP-FTIR system could be analyzed effectively to characterize differences in the location of sources. Although the traditional single-point samplings of emissions involves sampling various sources in a coke processing area at several different times and is a credible profiling of emissions, our findings strongly suggest that they are not nearly as efficient or as cost-effective as the continuous line average method used in this study. This method would make it easier and cheaper for engineers and health risk assessors to identify and to control fugitive volatile organic compound emissions and to improve environmental health.

Impact of emissions from the Los Angeles port region on San Diego air quality during regional transport events.

PubMed

Ault, Andrew P; Moore, Meagan J; Furutani, Hiroshi; Prather, Kimberly A

2009-05-15

Oceangoing ships emit an estimated 1.2-1.6 million metric tons (Tg) of PM10 per year and represent a significant source of air pollution to coastal communities. As shown herein, ship and other emissions near the Los Angeles and Long Beach Port region strongly influence air pollution levels in the San Diego area. During time periods with regional transport, atmospheric aerosol measurements in La Jolla, California show an increase in 0.5-1 microm sized single particles with unique signatures including soot, metals (i.e., vanadium, iron, and nickel), sulfate, and nitrate. These particles are attributed to primary emissions from residual oil sourcessuch as ships and refineries, as well as traffic in the port region, and secondary processing during transport. During regional transport events, particulate matter concentrations were 2-4 times higher than typical average concentrations from local sources, indicating the health, environmental, and climate impacts from these emission sources must be taken into consideration in the San Diego region. Unless significant regulations are imposed on shipping-related activities, these emission sources will become even more important to California air quality as cars and truck emissions undergo further regulations and residual oil sources such as shipping continue to expand.

Ammonia emissions from a grazed field estimated by miniDOAS measurements and inverse dispersion modelling

NASA Astrophysics Data System (ADS)

Bell, Michael; Flechard, Chris; Fauvel, Yannick; Häni, Christoph; Sintermann, Jörg; Jocher, Markus; Menzi, Harald; Hensen, Arjan; Neftel, Albrecht

2017-05-01

Ammonia (NH3) fluxes were estimated from a field being grazed by dairy cattle during spring by applying a backward Lagrangian stochastic model (bLS) model combined with horizontal concentration gradients measured across the field. Continuous concentration measurements at field boundaries were made by open-path miniDOAS (differential optical absorption spectroscopy) instruments while the cattle were present and for 6 subsequent days. The deposition of emitted NH3 to clean patches on the field was also simulated, allowing both net and gross emission estimates, where the dry deposition velocity (vd) was predicted by a canopy resistance (Rc) model developed from local NH3 flux and meteorological measurements. Estimated emissions peaked during grazing and decreased after the cattle had left the field, while control on emissions was observed from covariance with temperature, wind speed and humidity and wetness measurements made on the field, revealing a diurnal emission profile. Large concentration differences were observed between downwind receptors, due to spatially heterogeneous emission patterns. This was likely caused by uneven cattle distribution and a low grazing density, where hotspots of emissions would arise as the cattle grouped in certain areas, such as around the water trough. The spatial complexity was accounted for by separating the model source area into sub-sections and optimising individual source area coefficients to measured concentrations. The background concentration was the greatest source of uncertainty, and based on a sensitivity/uncertainty analysis the overall uncertainty associated with derived emission factors from this study is at least 30-40 %.Emission factors can be expressed as 6 ± 2 g NH3 cow-1 day-1, or 9 ± 3 % of excreted urine-N emitted as NH3, when deposition is not simulated and 7 ± 2 g NH3 cow-1 day-1, or 10 ± 3 % of excreted urine-N emitted as NH3, when deposition is included in the gross emission model. The results suggest that around 14 ± 4 % of emitted NH3 was deposited to patches within the field that were not affected by urine or dung.

A model to relate wind tunnel measurements to open field odorant emissions from liquid area sources

NASA Astrophysics Data System (ADS)

Lucernoni, F.; Capelli, L.; Busini, V.; Sironi, S.

2017-05-01

Waste Water Treatment Plants are known to have significant emissions of several pollutants and odorants causing nuisance to the near-living population. One of the purposes of the present work is to study a suitable model to evaluate odour emissions from liquid passive area sources. First, the models describing volatilization under a forced convection regime inside a wind tunnel device, which is the sampling device that typically used for sampling on liquid area sources, were investigated. In order to relate the fluid dynamic conditions inside the hood to the open field and inside the hood a thorough study of the models capable of describing the volatilization phenomena of the odorous compounds from liquid pools was performed and several different models were evaluated for the open field emission. By means of experimental tests involving pure liquid acetone and pure liquid butanone, it was verified that the model more suitable to describe precisely the volatilization inside the sampling hood is the model for the emission from a single flat plate in forced convection and laminar regime, with a fluid dynamic boundary layer fully developed and a mass transfer boundary layer not fully developed. The proportionality coefficient for the model was re-evaluated in order to account for the specific characteristics of the adopted wind tunnel device, and then the model was related with the selected model for the open field thereby computing the wind speed at 10 m that would cause the same emission that is estimated from the wind tunnel measurement furthermore, the field of application of the proposed model was clearly defined for the considered models during the project, discussing the two different kinds of compounds commonly found in emissive liquid pools or liquid spills, i.e. gas phase controlled and liquid phase controlled compounds. Lastly, a discussion is presented comparing the presented approach for emission rates recalculation in the field, with other approaches possible, i.e. the ones relying on the recalculation of the wind speed at the emission level, instead of the wind speed that would cause in the open field the same emission that is measured with the hood.

Tracking Reactive Nitrogen Sources, Chemistry and Deposition in Urban Environments Using Stable Isotopes

NASA Astrophysics Data System (ADS)

Hastings, M. G.; Clark, S. C.; Chai, J.; Joyce, E.; Miller, D. J.; Schiebel, H.; Walters, W.

2017-12-01

Reactive nitrogen (Nr) includes compounds such as nitrogen oxides (NOx, HONO), ammonia (NH3), nitrate (NO3-), ammonium (NH4+), and organic nitrates. These compounds serve major roles in controlling the composition of our atmosphere, and have a direct impact on ecosystem health and water quality. Our research is focused on using stable isotopes of Nr to investigate variations in sources, chemistry, atmospheric transport, and deposition. Our aim is to fingerprint distinct emission sources - such as vehicles, power plants, aircraft, agriculature, wildfires, and lightning - and track their influence in the environment. We have recently characterized vehicle emission plumes, emissions from agricultural soils under different management practices, and (in the near future) wildfire plumes in the western U.S. Our approach targets characterizing the isotopic composition of NOx, HONO, and NH3 at both the emissions source and the plume scale. In contrast to large ranges found for individual tailpipe emissions of NOx, on-road plumes in the U.S. have a mean δ15N of -4.7 ± 1.7‰. The plume scale approach integrates across the typical U.S. fleet giving a representative value that can be used for tracking the impact of this emission source in the environment. NH3 also tends towards a narrow isotopic range when considered at the roadside scale compared to individual vehicles. In agricultural settings, the isotopes of NOx and HONO released from soils under different fertilizer practices is typically very negative in δ15N (-40 to -10‰) and appears to vary most with soil N properties rather than meteorology. Our work is now extending to discern sources influencing Nr deposition in an urban area at the head of New England's largest estuary. National monitoring of N deposition shows decreases in NO3- (but not NH4+) deposition over the last two decades, following better controls on NOx emissions. Wet deposition collected in an urban area exhibits N concentrations that are often 3-5 times higher than that found in regional monitoring networks. An event-based, year-round record of the isotopic composition of NO3- and NH4+ in wet deposition is currently underway with the aim of constraining local versus transported emissions sources and understanding the implications of very concentrated deposition events on a major urban watershed.

A source strength model for prescribed fires in coniferous logging slash.

Treesearch

D.V. Sandberg; Janice Peterson

1984-01-01

Emission reduction has become an essential part of the effort to reduce air pollution from forest slash burning. The State of Washington has set a goal of reducing emissions by 35 percent by 1990, leaving the choice of emission reduction techniques to forest managers. Several thousand harvested areas are burned each year in the Northwest, encompassing a wide variety...

OTM 33 Geospatial Measurement of Air Pollution, Remote Emissions Quantification (GMAP-REQ) and OTM33A Geospatial Measurement of Air Pollution-Remote Emissions Quantification-Direct Assessment (GMAP-REQ-DA)

EPA Science Inventory

Background: Next generation air measurement (NGAM) technologies are enabling new regulatory and compliance approaches that will help EPA better understand and meet emerging challenges associated with fugitive and area source emissions from industrial and oil and gas sectors. In...

MEASUREMENT OF FUGITIVE EMISSIONS AT REGION I LANDFILL

EPA Science Inventory

This report discusses a new measurement technology for characterizing emissions from large area sources. This work was funded by EPA's Monitoring and Measurement for the 21st Century Initiative, or 21M2. The site selected for demonstrating this technology is a superfund landfil...

IUE detection of bursts of H Ly-alpha emission from Saturn

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Moos, H. W.; Atreya, S. K.; Lane, A. L.

1981-01-01

A new investigation is reported of the potential sources of Ly-alpha emission in a series of observations of the Saturnian system carried out between January and July 1980 using the short wavelength spectrograph of the IUE Observatory. It is noted that north-south maps of the Ly-alpha emission across the planet disk show pronounced spatial asymmetries in emission brightness. These asymmetries vary to a marked extent on a time scale of days and are interpreted as bursts of Ly-alpha emission of as much as 1 kR brightness averaged over a 6 x 10 arcsec area, above a constant planetary emission level of 700-800 R. In fact, the Ly-alpha emission peaks manifest themselves as essentially point source features in these data; it is pointed out that if the emitting region is smaller than the 6 x 10 arcsec instrumental resolution, the surface brightness must be proportionally higher.

On The Usage Of Fire Smoke Emissions In An Air Quality Forecasting System To Reduce Particular Matter Forecasting Error

NASA Astrophysics Data System (ADS)

Huang, H. C.; Pan, L.; McQueen, J.; Lee, P.; ONeill, S. M.; Ruminski, M.; Shafran, P.; DiMego, G.; Huang, J.; Stajner, I.; Upadhayay, S.; Larkin, N. K.

2016-12-01

Wildfires contribute to air quality problems not only towards primary emissions of particular matters (PM) but also emitted ozone precursor gases that can lead to elevated ozone concentration. Wildfires are unpredictable and can be ignited by natural causes such as lightning or accidently by human negligent behavior such as live cigarette. Although wildfire impacts on the air quality can be studied by collecting fire information after events, it is extremely difficult to predict future occurrence and behavior of wildfires for real-time air quality forecasts. Because of the time constraints of operational air quality forecasting, assumption of future day's fire behavior often have to be made based on observed fire information in the past. The United States (U.S.) NOAA/NWS built the National Air Quality Forecast Capability (NAQFC) based on the U.S. EPA CMAQ to provide air quality forecast guidance (prediction) publicly. State and local forecasters use the forecast guidance to issue air quality alerts in their area. The NAQFC fine particulates (PM2.5) prediction includes emissions from anthropogenic and biogenic sources, as well as natural sources such as dust storms and fires. The fire emission input to the NAQFC is derived from the NOAA NESDIS HMS fire and smoke detection product and the emission module of the US Forest Service BlueSky Smoke Modeling Framework. This study focuses on the error estimation of NAQFC PM2.5 predictions resulting from fire emissions. The comparisons between the NAQFC modeled PM2.5 and the EPA AirNow surface observation show that present operational NAQFC fire emissions assumption can lead to a huge error in PM2.5 prediction as fire emissions are sometimes placed at wrong location and time. This PM2.5 prediction error can be propagated from the fire source in the Northwest U.S. to downstream areas as far as the Southeast U.S. From this study, a new procedure has been identified to minimize the aforementioned error. An additional 24 hours reanalysis-run of NAQFC using same-day observed fire emission are being tested. Preliminary results have shown that this procedure greatly improves the PM2.5 predictions at both nearby and downstream areas from fire sources. The 24 hours reanalysis-run is critical and necessary especially during extreme fire events to provide better PM2.5 predictions.

MOVES (MOTOR VEHICLE EMISSION SIMULATOR) MODEL ...

EPA Pesticide Factsheets

A computer model, intended to eventually replace the MOBILE model and to incorporate the NONROAD model, that will provide the ability to estimate criteria and toxic air pollutant emission factors and emission inventories that are specific to the areas and time periods of interest, at scales ranging from local to national. Development of a new emission factor and inventory model for mobile source emissions. The model will be used by air pollution modelers within EPA, and at the State and local levels.

Overview of the SHARP campaign: Motivation, design, and major outcomes

NASA Astrophysics Data System (ADS)

Olaguer, Eduardo P.; Kolb, Charles E.; Lefer, Barry; Rappenglück, Bernhard; Zhang, Renyi; Pinto, Joseph P.

2014-03-01

The Study of Houston Atmospheric Radical Precursors (SHARP) was a field campaign developed by the Houston Advanced Research Center on behalf of the Texas Environmental Research Consortium. SHARP capitalized on previous research associated with the Second Texas Air Quality Study and the development of the State Implementation Plan (SIP) for the Houston-Galveston-Brazoria (HGB) ozone nonattainment area. These earlier studies pointed to an apparent deficit in ozone production in the SIP attainment demonstration model despite the enhancement of simulated emissions of highly reactive volatile organic compounds in accordance with the findings of the original Texas Air Quality Study in 2000. The scientific hypothesis underlying the SHARP campaign was that there are significant undercounted primary and secondary sources of the radical precursors, formaldehyde, and nitrous acid, in both heavily industrialized and more typical urban areas of Houston. These sources, if properly taken into account, could increase the production of ozone in the SIP model and the simulated efficacy of control strategies designed to bring the HGB area into ozone attainment. This overview summarizes the precursor studies and motivations behind SHARP, as well as the overall experimental design and major findings of the 2009 field campaign. These findings include significant combustion sources of formaldehyde at levels greater than accounted for in current point source emission inventories; the underestimation of formaldehyde and nitrous acid emissions, as well as CO/NOx and NO2/NOx ratios, by mobile source models; and the enhancement of nitrous acid by atmospheric organic aerosol.

Historic Emissions from Deforestation and Forest Degradation in Mato Grosso, Brazil: 1. Source Data Uncertainties

NASA Technical Reports Server (NTRS)

Morton, Douglas C.; Sales, Marcio H.; Souza, Carlos M., Jr.; Griscom, Bronson

2011-01-01

Historic carbon emissions are an important foundation for proposed efforts to Reduce Emissions from Deforestation and forest Degradation and enhance forest carbon stocks through conservation and sustainable forest management (REDD+). The level of uncertainty in historic carbon emissions estimates is also critical for REDD+, since high uncertainties could limit climate benefits from mitigation actions. Here, we analyzed source data uncertainties based on the range of available deforestation, forest degradation, and forest carbon stock estimates for the Brazilian state of Mato Grosso during 1990-2008. Results: Deforestation estimates showed good agreement for multi-year trends of increasing and decreasing deforestation during the study period. However, annual deforestation rates differed by >20% in more than half of the years between 1997-2008, even for products based on similar input data. Tier 2 estimates of average forest carbon stocks varied between 99-192 Mg C/ha, with greatest differences in northwest Mato Grosso. Carbon stocks in deforested areas increased over the study period, yet this increasing trend in deforested biomass was smaller than the difference among carbon stock datasets for these areas. Conclusions: Patterns of spatial and temporal disagreement among available data products provide a roadmap for future efforts to reduce source data uncertainties for estimates of historic forest carbon emissions. Specifically, regions with large discrepancies in available estimates of both deforestation and forest carbon stocks are priority areas for evaluating and improving existing estimates. Full carbon accounting for REDD+ will also require filling data gaps, including forest degradation and secondary forest, with annual data on all forest transitions.

Chemical characterization of fine organic aerosol for source apportionment at Monterrey, Mexico

NASA Astrophysics Data System (ADS)

Mancilla, Y.; Mendoza, A.; Fraser, M. P.; Herckes, P.

2015-07-01

Primary emissions from anthropogenic and biogenic sources as well as secondary formation are responsible for the pollution levels of ambient air in major urban areas. These sources release fine particles into the air that negatively impact human health and the environment. Organic molecular markers, which are compounds that are unique to specific PM2.5 sources, can be utilized to identify the major emission sources in urban areas. In this study, 43 representative PM2.5 samples, for both daytime and nighttime periods, were built from individual samples collected in an urban site of the Monterrey Metropolitan Area (MMA) during the spring and fall of 2011 and 2012. The samples were analyzed for organic carbon, elemental carbon, and organic molecular markers. Several diagnostic tools were employed for the preliminary identification of emission sources. Organic compounds for eight compound classes were quantified. The n-alkanoic acids were the most abundant, followed by n-alkanes, wood smoke markers, and levoglucosan/alkenoic acids. Polycyclic aromatic hydrocarbons (PAHs) and hopanes were less abundant. The carbon preference index (0.7-2.6) for n-alkanes indicate a major contribution of anthropogenic and mixed sources during the fall and the spring, respectively. Hopanes levels confirmed the contribution from gasoline and diesel engines. In addition, the contribution of gasoline and diesel vehicle exhaust was confirmed and identified by the PAH concentrations in PM2.5. Diagnostic ratios of PAH showed emissions from burning coal, wood, biomass, and other fossil fuels. The total PAH and elemental carbon (EC) were correlated (r2 = 0.39-0.70) across the monitoring periods, reinforcing that motor vehicles are the major contributors of PAH. Cholesterol levels remained constant during the spring and fall, showing evidence of the contribution of meat cooking operations, while the isolated concentrations of levoglucosan suggested occasional biomass burning events. Finally, source attribution results obtained using the CMB model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5. The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is the second study to explore the broad chemical characterization of fine organic aerosol in Mexico and the first for the MMA.

Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT

NASA Astrophysics Data System (ADS)

Hanabata, Y.; Katagiri, H.; Hewitt, J. W.; Ballet, J.; Fukazawa, Y.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Pedaletti, G.; Strong, A. W.; Torres, D. F.; Yamazaki, R.

2014-05-01

We present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4-0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800-240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides with radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s-1. Under the assumption that the γ-ray emission toward HESS J1800-240A, B, and C comes from π0 decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. The total energy of the CRs escaping from W28 is constrained through the same modeling to be larger than ~2 × 1049 erg. The emission from Source W can also be explained with the same CR escape scenario.

Nitrogen source effects on soil nitrous oxide emissions from strip-till corn.

PubMed

Halvorson, Ardell D; Del Grosso, Stephen J; Jantalia, Claudia Pozzi

2011-01-01

Nitrogen (N) application to crops generally results in increased nitrous oxide (NO) emissions. Commercially available, enhanced-efficiency N fertilizers were evaluated for their potential to reduce NO emissions from a clay loam soil compared with conventionally used granular urea and urea-ammonium nitrate (UAN) fertilizers in an irrigated strip-till (ST) corn ( L.) production system. Enhanced-efficiency N fertilizers evaluated were a controlled-release, polymer-coated urea (ESN), stabilized urea, and UAN products containing nitrification and urease inhibitors (SuperU and UAN+AgrotainPlus), and UAN containing a slow-release N source (Nfusion). Each N source was surface-band applied (202 kg N ha) at corn emergence and watered into the soil the next day. A subsurface-band ESN treatment was included. Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. All N sources had significantly lower growing season NO emissions than granular urea, with UAN+AgrotainPlus and UAN+Nfusion having lower emissions than UAN. Similar trends were observed when expressing NO emissions on a grain yield and N uptake basis. Loss of NO-N per kilogram of N applied was <0.8% for all N sources. Corn grain yields were not different among N sources but greater than treatments with no N applied. Selection of N fertilizer source can be a mitigation practice for reducing NO emissions in strip-till, irrigated corn in semiarid areas. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Detailed Investigation of the Gamma-Ray Emission in the Vicinity of SNR W28 with FERMI-LAT

NASA Technical Reports Server (NTRS)

Hanabata, Y.; Katagiri, H.; Hewitt, John William; Ballet, J.; Fukazawa, Y.; Fukui, Y.; Hayakawa, T.; Lemoine-Goumard, M.; Pedaletti, G.; Strong, A. W.;

Human Excreta as a Stable and Important Source of Atmospheric Ammonia in the Megacity of Shanghai

PubMed Central

Chang, Yunhua; Deng, Congrui; Dore, Anthony J.; Zhuang, Guoshun

2015-01-01

Although human excreta as a NH3 source has been recognized globally, this source has never been quantitatively determined in cities, hampering efforts to fully assess the causes of urban air pollution. In the present study, the exhausts of 15 ceiling ducts from collecting septic tanks in 13 buildings with 6 function types were selected to quantify NH3 emission rates in the megacity of Shanghai. As a comparison, the ambient NH3 concentrations across Shanghai were also measured at 13 atmospheric monitoring sites. The concentrations of NH3 in the ceiling ducts (2809−2661+5803 μg m-3) outweigh those of the open air (~10 μg m-3) by 2–3 orders of magnitude, and there is no significant difference between different seasons. δ15N values of NH3 emitted from two ceiling ducts are also seasonally consistent, suggesting that human excreta may be a stable source of NH3 in urban areas. The NH3 concentration levels were variable and dependent on the different building types and the level of human activity. NH3 emission rates of the six residential buildings (RBNH3) were in agreement with each other. Taking occupation time into account, we confined the range of the average NH3 emission factor for human excreta to be 2–4 times (with the best estimate of 3 times) of the averaged RBNH3 of 66.0±58.9 g NH3 capita-1 yr-1. With this emission factor, the population of ~21 million people living in the urban areas of Shanghai annually emitted approximately 1386 Mg NH3, which corresponds to over 11.4% of the total NH3 emissions in the Shanghai urban areas. The spatial distribution of NH3 emissions from human excreta based on population data was calculated for the city of Shanghai at a high-resolution (100×100 m). Our results demonstrate that human excreta should be included in official ammonia emission inventories. PMID:26656636

Tracking the Spatial Fate of PCDD/F Emissions from a Cement Plant by Using Lichens as Environmental Biomonitors.

PubMed

Augusto, Sofia; Pinho, Pedro; Santos, Artur; Botelho, Maria João; Palma-Oliveira, José; Branquinho, Cristina

2016-03-01

In an area with multiple sources of air pollution, it is difficult to evaluate the spatial impact of a minor source. Here, we describe the use of lichens to track minor sources of air pollution. The method was tested by transplanting lichens from a background area to the vicinity of a cement manufacturing plant that uses alternative fuel and is located in a Natural Park in an area surrounded by other important sources of pollution. After 7 months of exposure, the lichens were collected and analyzed for 17 PCDD/F congeners. The PCDD/F profiles of the exposed lichens were dominated by TCDF (50%) and OCDD (38%), which matched the profile of the emissions from the cement plant. The similarity in the profiles was greatest for lichens located northeast of the plant (i.e., in the direction of the prevailing winds during the study period), allowing us to evaluate the spatial impact of this source. The best match was found for sites located on the tops of mountains whose slopes faced the cement plant. Some of the sites with highest influence of the cement plant were the ones with the highest concentrations, whereas others were not. Thus, our newly developed lichen-based method provides a tool for tracking the spatial fate of industrially emitted PCDD/Fs regardless of their concentrations. The results showed that the method can be used to validate deposition models for PCDD/F industrial emissions in sites with several sources and characterized by complex orography.

Concentrations and Origins of Atmospheric Lead and Other Trace Species at a Rural Site in Northern China

NASA Technical Reports Server (NTRS)

Li, Can; Wen, Tianxue; Li, Zhanqing; Dickerson, Russell R.; Yang, Yongjie; Zhao, Yanan; Wang, Yuesi; Tsay, Si-Chee

2010-01-01

In this study we analyze the ambient levels of lead and other trace species in the bulk aerosol samples from a rural site approx.70 km ESE of Beijing in spring 2005. Lead (0.28+/-0.24 micro-g/cu m, average +/- standard deviation), along with several pollution \\related trace elements, was enriched by over 100 fold relative to the Earth's crust. The ambient lead levels showing large synoptic variations were well-correlated with other anthropogenic pollutants (e.g., CO and SO2). The Unmix receptor model resolved four factors in the aerosol composition data: a biomass burning source, an industrial and coal combustion source, a secondary aerosol source, and a dust source. The first three sources were strongest in weak southerly winds ahead of cold fronts, while the dust source peaked in strong northerly winds behind cold fronts. The second source, primarily representing emissions from industrial processes and relatively small \\scale coal burning such as in home and institutional heating, was identified as the main source of ambient lead in this study. Mobile sources might also contribute to this factor, but there was no distinct evidence of emissions due to combustion of leaded gasoline, despite a correlation between lead and CO. Potential source contribution function, calculated from backward trajectories and aerosol composition, further reveals that lead observed in this study was predominantly from the populated and industrialized areas to the south and SW of Xianghe, rather than Beijing to the west. Our results and several recent studies show that the lead levels in suburban areas near big cities in China, although generally lower than those in industrial districts and urban areas, are substantial (near or above 0.15 micro-g/cu m). More extensive studies on airborne lead and its emission sources in China are called for.

A review of studies on atmospheric mercury in China.

PubMed

Fu, Xuewu; Feng, Xinbin; Sommar, Jonas; Wang, Shaofeng

2012-04-01

Due to the fast developing economy, mercury (Hg) emissions to the atmosphere from Chinese mainland have increased rapidly in recent years. Consequently, this issue has received a considerable attention internationally. This paper reviews the current understanding of and knowledge on atmospheric Hg emissions, distribution and transport in China. The magnitude of Hg emissions to the atmosphere from Chinese anthropogenic sources has been estimated to be in the range of 500-700 tons per year, whereby comprising a significant proportion of the globe total anthropogenic emissions. Emissions of Hg from natural surfaces including bare soil, water, and vegetation covered soil tend in a comparison to be higher in China than in Europe and North America, indicating the importance of this source category. Atmospheric Hg exhibits a significant concentration variability among urban, semi-remote, and remote areas. Total Gaseous Mercury (TGM) concentrations in urban areas of China were often 1.5 - 5 folds higher compared to the corresponding settings in North America and Europe. In turn, particulate mercury (PHg) concentrations in urban areas of China were up to two orders of magnitude higher compared to North America and Europe. Atmospheric observations made at strictly remote sites in China also include the presence of occasional high concentrations of TGM, and the more short-lived fractions PHg and Reactive Gaseous Mercury (RGM). Accordingly, Hg deposition fluxes tended to be higher in China, with remote areas and urban areas being 1-2 times and 1-2 magnitude higher than those in North America and Europe, respectively. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Impact of Marcellus Shale natural gas development in southwest Pennsylvania on volatile organic compound emissions and regional air quality.

PubMed

Swarthout, Robert F; Russo, Rachel S; Zhou, Yong; Miller, Brandon M; Mitchell, Brittney; Horsman, Emily; Lipsky, Eric; McCabe, David C; Baum, Ellen; Sive, Barkley C

2015-03-03

The Marcellus Shale is the largest natural gas deposit in the U.S. and rapid development of this resource has raised concerns about regional air pollution. A field campaign was conducted in the southwestern Pennsylvania region of the Marcellus Shale to investigate the impact of unconventional natural gas (UNG) production operations on regional air quality. Whole air samples were collected throughout an 8050 km(2) grid surrounding Pittsburgh and analyzed for methane, carbon dioxide, and C1-C10 volatile organic compounds (VOCs). Elevated mixing ratios of methane and C2-C8 alkanes were observed in areas with the highest density of UNG wells. Source apportionment was used to identify characteristic emission ratios for UNG sources, and results indicated that UNG emissions were responsible for the majority of mixing ratios of C2-C8 alkanes, but accounted for a small proportion of alkene and aromatic compounds. The VOC emissions from UNG operations accounted for 17 ± 19% of the regional kinetic hydroxyl radical reactivity of nonbiogenic VOCs suggesting that natural gas emissions may affect compliance with federal ozone standards. A first approximation of methane emissions from the study area of 10.0 ± 5.2 kg s(-1) provides a baseline for determining the efficacy of regulatory emission control efforts.

Modeling urban air pollution in Budapest using WRF-Chem model

NASA Astrophysics Data System (ADS)

Kovács, Attila; Leelőssy, Ádám; Lagzi, István; Mészáros, Róbert

2017-04-01

Air pollution is a major problem for urban areas since the industrial revolution, including Budapest, the capital and largest city of Hungary. The main anthropogenic sources of air pollutants are industry, traffic and residential heating. In this study, we investigated the contribution of major industrial point sources to the urban air pollution in Budapest. We used the WRF (Weather Research and Forecasting) nonhydrostatic mesoscale numerical weather prediction system online coupled with chemistry (WRF-Chem, version 3.6).The model was configured with three nested domains with grid spacings of 15, 5 and 1 km, representing Central Europe, the Carpathian Basin and Budapest with its surrounding area. Emission data was obtained from the National Environmental Information System. The point source emissions were summed in their respective cells in the second nested domain according to latitude-longitude coordinates. The main examined air pollutants were carbon monoxide (CO) and nitrogen oxides (NOx), from which the secondary compound, ozone (O3) forms through chemical reactions. Simulations were performed under different weather conditions and compared to observations from the automatic monitoring site of the Hungarian Air Quality Network. Our results show that the industrial emissions have a relatively weak role in the urban background air pollution, confirming the effect of industrial developments and regulations in the recent decades. However, a few significant industrial sources and their impact area has been demonstrated.

Emission Sectoral Contributions of Foreign Emissions to Particulate Matter Concentrations over South Korea

NASA Astrophysics Data System (ADS)

Kim, E.; Kim, S.; Kim, H. C.; Kim, B. U.; Cho, J. H.; Woo, J. H.

2017-12-01

In this study, we investigated the contributions of major emission source categories located upwind of South Korea to Particulate Matter (PM) in South Korea. In general, air quality in South Korea is affected by anthropogenic air pollutants emitted from foreign countries including China. Some studies reported that foreign emissions contributed 50 % of annual surface PM total mass concentrations in the Seoul Metropolitan Area, South Korea in 2014. Previous studies examined PM contributions of foreign emissions from all sectors considering meteorological variations. However, little studies conducted to assess contributions of specific foreign source categories. Therefore, we attempted to estimate sectoral contributions of foreign emissions from China to South Korea PM using our air quality forecasting system. We used Model Inter-Comparison Study in Asia 2010 for foreign emissions and Clean Air Policy Support System 2010 emission inventories for domestic emissions. To quantify contributions of major emission sectors to South Korea PM, we applied the Community Multi-scale Air Quality system with brute force method by perturbing emissions from industrial, residential, fossil-fuel power plants, transportation, and agriculture sectors in China. We noted that industrial sector was pre-dominant over the region except during cold season for primary PMs when residential emissions drastically increase due to heating demand. This study will benefit ensemble air quality forecasting and refined control strategy design by providing quantitative assessment on seasonal contributions of foreign emissions from major source categories.

Trends and Patterns in a New Time Series of Natural and Anthropogenic Methane Emissions, 1980-2000

NASA Astrophysics Data System (ADS)

Matthews, E.; Bruhwiler, L.; Themelis, N. J.

2007-12-01

We report on a new time series of methane (CH4) emissions from anthropogenic and natural sources developed for a multi-decadal methane modeling study (see following presentation by Bruhwiler et al.). The emission series extends from 1980 through the early 2000s with annual emissions for all countries has several features distinct from the source histories based on IPCC methods typically employed in modeling the global methane cycle. Fossil fuel emissions rely on 7 fuel-process emission combinations and minimize reliance on highly-uncertain emission factors. Emissions from ruminant animals employ regional profiles of bovine populations that account for the influence of variable age- and size-demographics on emissions and are ~15% lower than other estimates. Waste-related emissions are developed using an approach that avoids using of data-poor emission factors and accounts for impacts of recycling and thermal treatment of waste on diverting material from landfills and CH4 capture at landfill facilities. Emissions from irrigated rice use rice-harvest areas under 3 water-management systems and a new historical data set that analyzes multiple sources for trends in water management since 1980. A time series of emissions from natural wetlands was developed by applying a multiple-regression model derived from full process-based model of Walter with analyzed meteorology from the ERA-40 reanalysis.

Concentration, ozone formation potential and source analysis of volatile organic compounds (VOCs) in a thermal power station centralized area: A study in Shuozhou, China.

PubMed

Yan, Yulong; Peng, Lin; Li, Rumei; Li, Yinghui; Li, Lijuan; Bai, Huiling

2017-04-01

Volatile organic compounds (VOCs) from two sampling sites (HB and XB) in a power station centralized area, in Shuozhou city, China, were sampled by stainless steel canisters and measured by gas chromatography-mass selective detection/flame ionization detection (GC-MSD/FID) in the spring and autumn of 2014. The concentration of VOCs was higher in the autumn (HB, 96.87 μg/m 3 ; XB, 58.94 μg/m 3 ) than in the spring (HB, 41.49 μg/m 3 ; XB, 43.46 μg/m 3 ), as lower wind speed in the autumn could lead to pollutant accumulation, especially at HB, which is a new urban area surrounded by residential areas and a transportation hub. Alkanes were the dominant group at both HB and XB in both sampling periods, but the contribution of aromatic pollutants at HB in the autumn was much higher than that of the other alkanes (11.16-19.55%). Compared to other cities, BTEX pollution in Shuozhou was among the lowest levels in the world. Because of the high levels of aromatic pollutants, the ozone formation potential increased significantly at HB in the autumn. Using the ratio analyses to identify the age of the air masses and analyze the sources, the results showed that the atmospheric VOCs at XB were strongly influenced by the remote sources of coal combustion, while at HB in the spring and autumn were affected by the remote sources of coal combustion and local sources of vehicle emission, respectively. Source analysis conducted using the Positive Matrix Factorization (PMF) model at Shuozhou showed that coal combustion and vehicle emissions made the two largest contributions (29.98% and 21.25%, respectively) to atmospheric VOCs. With further economic restructuring, the influence of vehicle emissions on the air quality should become more significant, indicating that controlling vehicle emissions is key to reducing the air pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 63.1340 - Applicability and designation of affected sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CATEGORIES National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing... portland cement plant which is a major source or an area source as defined in § 63.2. (b) The affected... portland cement plant which is a major source; (3) Each raw mill at any portland cement plant which is a...

40 CFR 63.11561 - What are my standards and management practices?

Code of Federal Regulations, 2013 CFR

2013-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Standards and Compliance Requirements § 63.11561 What are my standards and management practices? (a) For asphalt processing operations, you must meet the emission limits...

40 CFR 63.11561 - What are my standards and management practices?

Code of Federal Regulations, 2012 CFR

2012-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Standards and Compliance Requirements § 63.11561 What are my standards and management practices? (a) For asphalt processing operations, you must meet the emission limits...

40 CFR 63.11561 - What are my standards and management practices?

Code of Federal Regulations, 2014 CFR

2014-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Standards and Compliance Requirements § 63.11561 What are my standards and management practices? (a) For asphalt processing operations, you must meet the emission limits...

40 CFR 63.11561 - What are my standards and management practices?

Code of Federal Regulations, 2011 CFR

2011-07-01

... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Area Sources: Asphalt Processing and Asphalt Roofing Manufacturing Standards and Compliance Requirements § 63.11561 What are my standards and management practices? (a) For asphalt processing operations, you must meet the emission limits...

TRANSIT BUS LOAD-BASED MODAL EMISSION RATE MODEL DEVELOPMENT

EPA Science Inventory

Heavy-duty diesel vehicles (HDDVs) operations are a major source of oxides of nitrogen (NOx) and particulate matter (PM) emissions in metropolitan area nationwide. Although HD¬DVs constitute a small portion of the on-road fleet, they typically contribute more than 45% of NOx and ...

The Potential of Solar as Alternative Energy Source for Socio-Economic Wellbeing in Rural Areas, Malaysia

NASA Astrophysics Data System (ADS)

Alam, Rashidah Zainal; Siwar, Chamhuri; Ludin, Norasikin Ahmad

Malaysia's energy sector is highly dependent on fossil fuels as a primary energy source. Economic growth and socio-economic wellbeing also rely on the utilization of energy in daily life routine. Nevertheless, the increasing cost for electricity and declining fossil fuels resources causes various negative impacts to the people and environment especially in rural areas. This prompted Malaysia to shift towards alternative energy sources such as solar energy to ensure social, economic and environmental benefits. The solar energy is one of the potential renewable energy sources in tropical countries particularly in Malaysia. The paper attempts to analyze the benefits and advantages related to energy efficiency of solar for sustainable energy use and socio economic wellbeing in rural areas, Malaysia. The paper uses secondary sources of data such as policies, regulations and research reports from relevant ministries and agencies to attain the objectives. As a signatory country to the UN Convention on Climate Change and the Kyoto Protocol, Malaysia has taken initiatives for decreasing energy dependence on oil to reduce greenhouse gas emissions (GHG) for sustainable development. The paper shows solar energy becomes one of the promising alternative energy sources to alleviate energy poverty in Malaysia for rural areas. Finally, solar energy has increased socio-economic wellbeing and develops green potential and toward achieving energy efficiency in energy sector of Malaysia by preserving environment as well as reducing carbon emission.

Locally Resolved Electron Emission Area and Unified View of Field Emission from Ultrananocrystalline Diamond Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubenko, Oksana; Baturin, Stanislav S.; Kovi, Kiran K.

One of the common problems in case of field emission from polycrystalline diamond films, which typically have uniform surface morphology, is uncertainty in determining exact location of electron emission sites across the surface. Although several studies have suggested that grain boundaries are the main electron emission source, it is not particularly clear what makes some sites emit more than the others. It is also practically unclear how one could quantify the actual electron emission area and therefore field emission current per unit area. In this paper we study the effect of actual, locally resolved, field emission (FE) area on electronmore » emission characteristics of uniform planar highly conductive nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) field emitters. It was routinely found that field emission from as-grown planar (N)UNCD films is always confined to a counted number of discrete emitting centers across the surface which varied in size and electron emissivity. It was established that the actual FE area critically depends on the applied electric field, as well as that the actual FE area and the overall electron emissivity improve with sp2 fraction present in the film irrespectively of the original substrate roughness and morphology. To quantify the actual FE area and its dependence on the applied electric field, imaging experiments were carried out in a vacuum system in a parallel-plate configuration with a specialty anode phosphor screen. Electron emission micrographs were taken concurrently with I-V characteristics measurements. In addition, a novel automated image processing algorithm was developed to process extensive imaging datasets and calculate emission area per image. By doing so, it was determined that the emitting area was always significantly smaller than the FE cathode surface area. Namely, the actual FE area would change from 5×10-3 % to 1.5 % of the total cathode area with the applied electric field increased. Finally and most importantly, it was shown that when I-E curves as measured in the experiment were normalized by the field-dependent emission area, the resulting j-E curves demonstrated a strong kink and significant deviation from Fowler-Nordheim (FN) law, and eventually saturated at a current density of ~100 mA/cm2 . This value was nearly identical for all (N)UNCD films measured in this study, regardless of the substrate.« less

Vista-LA: Mapping methane-emitting infrastructure in the Los Angeles megacity

NASA Astrophysics Data System (ADS)

Carranza, Valerie; Rafiq, Talha; Frausto-Vicencio, Isis; Hopkins, Francesca M.; Verhulst, Kristal R.; Rao, Preeti; Duren, Riley M.; Miller, Charles E.

2018-03-01

Methane (CH4) is a potent greenhouse gas (GHG) and a critical target of climate mitigation efforts. However, actionable emission reduction efforts are complicated by large uncertainties in the methane budget on relevant scales. Here, we present Vista, a Geographic Information System (GIS)-based approach to map potential methane emissions sources in the South Coast Air Basin (SoCAB) that encompasses Los Angeles, an area with a dense, complex mixture of methane sources. The goal of this work is to provide a database that, together with atmospheric observations, improves methane emissions estimates in urban areas with complex infrastructure. We aggregated methane source location information into three sectors (energy, agriculture, and waste) following the frameworks used by the State of California GHG Inventory and the Intergovernmental Panel on Climate Change (IPCC) Guidelines for GHG Reporting. Geospatial modeling was applied to publicly available datasets to precisely geolocate facilities and infrastructure comprising major anthropogenic methane source sectors. The final database, Vista-Los Angeles (Vista-LA), is presented as maps of infrastructure known or expected to emit CH4. Vista-LA contains over 33 000 features concentrated on < 1 % of land area in the region. Currently, Vista-LA is used as a planning and analysis tool for atmospheric measurement surveys of methane sources, particularly for airborne remote sensing, and methane hotspot detection using regional observations. This study represents a first step towards developing an accurate, spatially resolved methane flux estimate for point sources in SoCAB, with the potential to address discrepancies between bottom-up and top-down methane emissions accounting in this region. The Vista-LA datasets and associated metadata are available from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (ORNL DAAC; https://doi.org/10.3334/ORNLDAAC/1525).

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005-2014

DOE PAGES

Lu, Z.; Streets, D. G.; de Foy, B.; ...

2015-05-28

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially-modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate three-year moving-average emissions of summertime NO x from 35 US urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following the conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applying the EMGmore » method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s -1) are qualitatively better correlated with the surface NO x source strength in comparison to all-wind OMI maps; and therefore we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous, EMG-obtained, effective NO 2 lifetimes (~3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in three-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49%, consistent with reductions of 43, 47, 49, and 44% in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3% yr -1) before 2010 and slower (i.e., -3.4 to -4.9% yr -1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements; and high correlations are found for all urban areas (median R = 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005–2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Z.; Streets, D. G.; de Foy, B.

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate 3-year moving-average emissions of summertime NO x from 35 US (United States) urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applyingmore » the EMG method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s −1) are qualitatively better correlated to the surface NO x source strength in comparison to all-wind OMI maps; therefore, we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as with bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous EMG-obtained effective NO 2 lifetimes (~ 3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in 3-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49 %, consistent with reductions of 43, 47, 49, and 44 % in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3 % yr −1) before 2010 and slower (i.e., -3.4 to -4.9 % yr −1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements, and high correlations are found for all urban areas (median R= 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Emissions of nitrogen oxides from US urban areas: estimation from Ozone Monitoring Instrument retrievals for 2005-2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Z.; Streets, D. G.; de Foy, B.

Satellite remote sensing of tropospheric nitrogen dioxide (NO 2) can provide valuable information for estimating surface nitrogen oxides (NO x) emissions. Using an exponentially-modified Gaussian (EMG) method and taking into account the effect of wind on observed NO 2 distributions, we estimate three-year moving-average emissions of summertime NO x from 35 US urban areas directly from NO 2 retrievals of the Ozone Monitoring Instrument (OMI) during 2005–2014. Following the conclusions of previous studies that the EMG method provides robust and accurate emission estimates under strong-wind conditions, we derive top-down NO x emissions from each urban area by applying the EMGmore » method to OMI data with wind speeds greater than 3–5 m s -1. Meanwhile, we find that OMI NO 2 observations under weak-wind conditions (i.e., < 3 m s -1) are qualitatively better correlated with the surface NO x source strength in comparison to all-wind OMI maps; and therefore we use them to calculate the satellite-observed NO 2 burdens of urban areas and compare with NO x emission estimates. The EMG results show that OMI-derived NO x emissions are highly correlated ( R > 0.93) with weak-wind OMI NO 2 burdens as well as bottom-up NO x emission estimates over 35 urban areas, implying a linear response of the OMI observations to surface emissions under weak-wind conditions. The simultaneous, EMG-obtained, effective NO 2 lifetimes (~3.5 ± 1.3 h), however, are biased low in comparison to the summertime NO 2 chemical lifetimes. In general, isolated urban areas with NO x emission intensities greater than ~ 2 Mg h -1 produce statistically significant weak-wind signals in three-year average OMI data. From 2005 to 2014, we estimate that total OMI-derived NO x emissions over all selected US urban areas decreased by 49%, consistent with reductions of 43, 47, 49, and 44% in the total bottom-up NO x emissions, the sum of weak-wind OMI NO 2 columns, the total weak-wind OMI NO 2 burdens, and the averaged NO 2 concentrations, respectively, reflecting the success of NO x control programs for both mobile sources and power plants. The decrease rates of these NO x-related quantities are found to be faster (i.e., -6.8 to -9.3% yr -1) before 2010 and slower (i.e., -3.4 to -4.9% yr -1) after 2010. For individual urban areas, we calculate the R values of pair-wise trends among the OMI-derived and bottom-up NO x emissions, the weak-wind OMI NO 2 burdens, and ground-based NO 2 measurements; and high correlations are found for all urban areas (median R = 0.8), particularly large ones ( R up to 0.97). The results of the current work indicate that using the EMG method and considering the wind effect, the OMI data allow for the estimation of NO x emissions from urban areas and the direct constraint of emission trends with reasonable accuracy.« less

Local sources of pollution and their impacts in Alaska (Invited)

NASA Astrophysics Data System (ADS)

Molders, N.

2013-12-01

The movie 'Into the Wilde' evoke the impression of the last frontier in a great wide and pristine land. With over half a million people living in Alaska an area as larger as the distance from the US West to the East Coast, this idea comes naturally. The three major cities are the main emission source in an otherwise relative clean atmosphere. On the North Slope oil drilling and production is the main anthropogenic emission sources. Along Alaska's coasts ship traffic including cruises is another anthropogenic emission source that is expected to increase as sea-ice recedes. In summer, wildfires in Alaska, Canada and/or Siberia may cause poor air quality. In winter inversions may lead poor air quality and in spring. In spring, aged polluted air is often advected into Alaska. These different emission sources yield quite different atmospheric composition and air quality impacts. While this may make understanding Alaska's atmospheric composition at-large a challenging task, it also provides great opportunities to examine impacts without co-founders. The talk will give a review of the performed research, and insight into the challenges.

Neotropical peatland methane emissions along a vegetation and biogeochemical gradient.

PubMed

Winton, R Scott; Flanagan, Neal; Richardson, Curtis J

2017-01-01

Tropical wetlands are thought to be the most important source of interannual variability in atmospheric methane (CH4) concentrations, yet sparse data prevents them from being incorporated into Earth system models. This problem is particularly pronounced in the neotropics where bottom-up models based on water table depth are incongruent with top-down inversion models suggesting unaccounted sinks or sources of CH4. The newly documented vast areas of peatlands in the Amazon basin may account for an important unrecognized CH4 source, but the hydrologic and biogeochemical controls of CH4 dynamics from these systems remain poorly understood. We studied three zones of a peatland in Madre de Dios, Peru, to test whether CH4 emissions and pore water concentrations varied with vegetation community, soil chemistry and proximity to groundwater sources. We found that the open-canopy herbaceous zone emitted roughly one-third as much CH4 as the Mauritia flexuosa palm-dominated areas (4.7 ± 0.9 and 14.0 ± 2.4 mg CH4 m-2 h-1, respectively). Emissions decreased with distance from groundwater discharge across the three sampling sites, and tracked changes in soil carbon chemistry, especially increased soil phenolics. Based on all available data, we calculate that neotropical peatlands contribute emissions of 43 ± 11.9 Tg CH4 y-1, however this estimate is subject to geographic bias and will need revision once additional studies are published.

77 FR 75739 - National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-21

...On January 30, 2012, the EPA proposed revisions to several provisions of the final National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources. The proposed revisions were made, in part, in response to a petition for reconsideration received by the Administrator following the promulgation of the October 29, 2009, final rule (``2009 final rule''). In this action, the EPA is finalizing those amendments, lifting the stay of the title V permit requirement issued on March 14, 2011, and lifting the stay of the final rule issued on October 25, 2012. In addition, this final action includes revisions to the EPA's approach for addressing malfunctions and standards applicable during startup and shutdown periods. This final action also includes amendments and technical corrections to the final rule to clarify applicability and compliance issues raised by stakeholders subject to the 2009 final rule. The revisions to the final rule do not reduce the level of environmental protection or emissions control on sources regulated by this rule but provide flexibility and clarity to improve implementation. This action also extends the compliance date for existing sources and the EPA's final response to all issues raised in the petition for reconsideration.

Aircraft Observations of Nitrous Oxide (N2O) in the San Joaquin Valley of California

NASA Astrophysics Data System (ADS)

Muto, S.; Herrera, S.; Pusede, S.

2017-12-01

Agriculture is the largest source of anthropogenic nitrous oxide (N2O) in the U.S. While it is generally known which processes produce N2O, there is considerable uncertainty in controls over N2O emissions. Factors that determine N2O fluxes, such as soil properties and manure management, are highly variable in space and time, and, as a result, it has proven difficult to upscale chamber-derived soil flux measurements to regional spatial scales. Aircraft observations provide a regional picture of the N2O spatial distribution, but, because N2O is very long-lived, it is challenging to attribute measured concentrations of N2O to distinct local sources, especially over areas with complex and integrated land use. This study takes advantage of a novel aircraft N2O dataset collected onboard the low-flying, slow-moving NASA C-23 Sherpa in the San Joaquin Valley (SJV) of California, a region with a variety of N2O sources, including dairies, feedlots, fertilized cropland, and industrial facilities. With these measurements, we link observed N2O enhancements to specific sources at sub-inventory spatial scales. We compare our results with area-weighted emission profiles obtained by integrating detailed emission inventory data, agricultural statistics, and GIS source mapping.

Factors influencing mobile source particulate matter emissions-to-exposure relationships in the Boston urban area.

PubMed

Greco, Susan L; Wilson, Andrew M; Hanna, Steven R; Levy, Jonathan I

2007-11-15

Benefit-cost and regulatory impact analyses often use atmospheric dispersion models with coarse resolution to estimate the benefits of proposed mobile source emission control regulations. This approach may bias health estimates or miss important intra-urban variability for primary air pollutants. In this study, we estimate primary fine particulate matter (PM2.5) intake fractions (iF; the fraction of a pollutant emitted from a source that is inhaled by the population) for each of 23 398 road segments in the Boston Metro Core area to evaluate the potential for intra-urban variability in the emissions-to-exposure relationship. We estimate iFs using the CAL3QHCR line source model combined with residential populations within 5000 m of each road segment. The annual average values for the road segments range from 0.8 to 53 per million, with a mean of 12 per million. On average, 46% of the total exposure is realized within 200 m of the road segment, though this varies from 0 to 93% largely due to variable population patterns. Our findings indicate the likelihood of substantial intra-urban variability in mobile source primary PM2.5 iF that accounting for population movement with time, localized meteorological conditions, and street-canyon configurations would likely increase.

Removal of sulfur dioxide and formation of sulfate aerosol in Tokyo

NASA Astrophysics Data System (ADS)

Miyakawa, T.; Takegawa, N.; Kondo, Y.

2007-07-01

Ground-based in situ measurements of sulfur dioxide (SO2) and submicron sulfate aerosol (SO42-) together with carbon monoxide (CO) were conducted at an urban site in Tokyo, Japan from spring 2003 to winter 2004. The observed concentrations of SO2 were affected dominantly by anthropogenic emissions (for example, manufacturing industries) in source areas, while small fraction of the data (<30%) was affected by large point sources of SO2 (power plant and volcano). Although emission sources of CO in Tokyo are different from those of SO2, the major emission sources of CO and SO2 are colocated, indicating that CO can be used as a tracer of anthropogenic SO2 emissions in Tokyo. The ratio of SO42- to total sulfur compounds (SOx = SO2 + SO42-) and the remaining fraction of SOx, which is derived as the ratio of the linear regression slope of the SOx-CO correlation, is used as measures for the formation of SO42- and removal of SOx, respectively. Using these parameters, the average formation efficiency of SO42- (i.e., amount of SO42- produced per SO2 emitted from emission sources) are estimated to be 0.18 and 0.03 in the summer and winter periods, respectively. A simple box model was developed to estimate the lifetime of SOx. The lifetime of SOx for the summer period (26 h) is estimated to be about two times longer than that for the winter period (14 h). The seasonal variations of the remaining fraction of SOx, estimated formation efficiency of SO42-, and lifetime of SOx are likely due to those of the boundary layer height and photochemical activity (i.e., hydroxyl radical). These results provide useful insights into the formation and removal processes of sulfur compounds exported from an urban area.

Photochemical Grid Modelling Study to Assess Potential Air Quality Impacts Associated with Energy Development in Colorado and Northern New Mexico.

NASA Astrophysics Data System (ADS)

Parker, L. K.; Morris, R. E.; Zapert, J.; Cook, F.; Koo, B.; Rasmussen, D.; Jung, J.; Grant, J.; Johnson, J.; Shah, T.; Pavlovic, T.

2015-12-01

The Colorado Air Resource Management Modeling Study (CARMMS) was funded by the Bureau of Land Management (BLM) to predict the impacts from future federal and non-federal energy development in Colorado and Northern New Mexico. The study used the Comprehensive Air Quality Model with extensions (CAMx) photochemical grid model (PGM) to quantify potential impacts from energy development from BLM field office planning areas. CAMx source apportionment technology was used to track the impacts from multiple (14) different emissions source regions (i.e. field office areas) within one simulation, as well as to assess the cumulative impact of emissions from all source regions combined. The energy development emissions estimates were for the year 2021 for three different development scenarios: (1) low; (2) high; (3) high with emissions mitigation. Impacts on air quality (AQ) including ozone, PM2.5, PM10, NO2, SO2, and air quality related values (AQRVs) such as atmospheric deposition, regional haze and changes in Acid Neutralizing Capacity (ANC) of lakes were quantified, and compared to establish threshold levels. In this presentation, we present a brief summary of the how the emission scenarios were developed, we compare the emission totals for each scenario, and then focus on the ozone impacts for each scenario to assess: (1). the difference in potential ozone impacts under the different development scenarios and (2). to establish the sensitivity of the ozone impacts to different emissions levels. Region-wide ozone impacts will be presented as well as impacts at specific locations with ozone monitors.

A novel method for the activity measurement of large-area beta reference sources.

PubMed

Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ioan, M R

2016-03-01

A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ((60)Co and (137)Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Greenland records of aerosol source and atmospheric lifetime changes from the Eemian to the Holocene.

PubMed

Schüpbach, S; Fischer, H; Bigler, M; Erhardt, T; Gfeller, G; Leuenberger, D; Mini, O; Mulvaney, R; Abram, N J; Fleet, L; Frey, M M; Thomas, E; Svensson, A; Dahl-Jensen, D; Kettner, E; Kjaer, H; Seierstad, I; Steffensen, J P; Rasmussen, S O; Vallelonga, P; Winstrup, M; Wegner, A; Twarloh, B; Wolff, K; Schmidt, K; Goto-Azuma, K; Kuramoto, T; Hirabayashi, M; Uetake, J; Zheng, J; Bourgeois, J; Fisher, D; Zhiheng, D; Xiao, C; Legrand, M; Spolaor, A; Gabrieli, J; Barbante, C; Kang, J-H; Hur, S D; Hong, S B; Hwang, H J; Hong, S; Hansson, M; Iizuka, Y; Oyabu, I; Muscheler, R; Adolphi, F; Maselli, O; McConnell, J; Wolff, E W

2018-04-16

The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little.

Mobile source CO2 mitigation through smart growth development and vehicle fleet hybridization.

PubMed

Stone, Brian; Mednick, Adam C; Holloway, Tracey; Spak, Scott N

2009-03-15

This paper presents the results of a study on the effectiveness of smart growth development patterns and vehicle fleet hybridization in reducing mobile source emissions of carbon dioxide (CO2) across 11 major metropolitan regions of the Midwestern U.S. over a 50-year period. Through the integration of a vehicle travel activity modeling framework developed by researchers atthe Oak Ridge National Laboratory with small area population projections, we model mobile source emissions of CO2 associated with alternative land development and technology change scenarios between 2000 and 2050. Our findings suggest that under an aggressive smart growth scenario, growth in emissions expected to occur under a business as usual scenario is reduced by 34%, while the full dissemination of hybrid-electric vehicles throughout the light vehicle fleet is found to offset the expected growth in emissions by 97%. Our results further suggest that high levels of urban densification could achieve reductions in 2050 CO2 emissions equivalent to those attainable through the full dissemination of hybrid-electric vehicle technologies.

Hot emission model for mobile sources: application to the metropolitan region of the city of Santiago, Chile.

PubMed

Corvalán, Roberto M; Osses, Mauricio; Urrutia, Cristian M

2002-02-01

Depending on the final application, several methodologies for traffic emission estimation have been developed. Emission estimation based on total miles traveled or other average factors is a sufficient approach only for extended areas such as national or worldwide areas. For road emission control and strategies design, microscale analysis based on real-world emission estimations is often required. This involves actual driving behavior and emission factors of the local vehicle fleet under study. This paper reports on a microscale model for hot road emissions and its application to the metropolitan region of the city of Santiago, Chile. The methodology considers the street-by-street hot emission estimation with its temporal and spatial distribution. The input data come from experimental emission factors based on local driving patterns and traffic surveys of traffic flows for different vehicle categories. The methodology developed is able to estimate hourly hot road CO, total unburned hydrocarbons (THCs), particulate matter (PM), and NO(x) emissions for predefined day types and vehicle categories.

The Fermi Large Area Telescope Thrid Gamma-ray Source Catalog

NASA Astrophysics Data System (ADS)

Stephens, Thomas E.; Ballet, Jean; Burnett, Toby; Cavazzuti, Elisabetta; Digel, Seth William; Fermi LAT Collaboration

2015-01-01

We present an overview of the third Fermi Large Area Telescope source catalog (3FGL) of sources in the 100 MeV - 300 GeV range. Based on the first four years of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the 2FGL catalog (Nolan et al. 2012, ApJS 199, 31), the 3FGL catalog incorporates twice as much data as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources, with source location regions, spectral properties, and monthly light curves for each. For approximately one-third of the sources we have not found counterparts at other wavelengths. More than 1100 of the identified or associated sources are active galaxies of the blazar class; several other classes of non-blazar active galaxies are also represented in the 3FGL. Pulsars represent the largest Galactic source class. From source counts of Galactic sources we estimate the contribution of unresolved sources to the Galactic diffuse emission.

The California Baseline Methane Survey

NASA Astrophysics Data System (ADS)

Duren, R. M.; Thorpe, A. K.; Hopkins, F. M.; Rafiq, T.; Bue, B. D.; Prasad, K.; Mccubbin, I.; Miller, C. E.

2017-12-01

The California Baseline Methane Survey is the first systematic, statewide assessment of methane point source emissions. The objectives are to reduce uncertainty in the state's methane budget and to identify emission mitigation priorities for state and local agencies, utilities and facility owners. The project combines remote sensing of large areas with airborne imaging spectroscopy and spatially resolved bottom-up data sets to detect, quantify and attribute emissions from diverse sectors including agriculture, waste management, oil and gas production and the natural gas supply chain. Phase 1 of the project surveyed nearly 180,000 individual facilities and infrastructure components across California in 2016 - achieving completeness rates ranging from 20% to 100% per emission sector at < 5 meters spatial resolution. Additionally, intensive studies of key areas and sectors were performed to assess source persistence and variability at times scales ranging from minutes to months. Phase 2 of the project continues with additional data collection in Spring and Fall 2017. We describe the survey design and measurement, modeling and analysis methods. We present initial findings regarding the spatial, temporal and sectoral distribution of methane point source emissions in California and their estimated contribution to the state's total methane budget. We provide case-studies and lessons learned about key sectors including examples where super-emitters were identified and mitigated. We summarize challenges and recommendations for future methane research, inventories and mitigation guidance within and beyond California.

Health risk assessment of emissions of dioxins and furans from a municipal waste incinerator: comparison with other emission sources.

PubMed

Meneses, Montse; Schuhmacher, Marta; Domingo, José L

2004-06-01

The aim of this study was to calculate the incremental lifetime-risk to dioxins and furans (PCDD/Fs) for the population living in the surroundings of a municipal solid waste incinerator (MSWI), as well as to establish the potential reduction on human health risks as a consequence of the adaptation to the EU legislation on pollutant emissions from the MSWI stack. Analytical and modelled results were obtained. PCDD/F concentrations in environmental media were determined by means of a simple-compartment-multimedia model (air-soil-vegetation model). Predicted and measured PCDD/F concentrations in soils and vegetation were compared, and the effects of MSWI emissions in the environmental media were determined. Human health risks due to PCDD/F emissions from the MSWI were also estimated based on I-TEQ measured and modelled in various environmental media. Cancer risks due to PCDD/F emissions of the plant were 1.07E-07 and 3.08E-09, before and after installation of the clean air system, respectively. On the other hand, cancer risks due to other PCDD/F emission sources in the area were 5.54E-06 and 1.86E-06. Total PCDD/F cancer risks (including those from diet) for the population living in the vicinity of the MSWI were 1.3E-04 and 4.25E-05, respectively (67.6% of reduction). Hazard ratio for total PCDD/F exposure (including diet) decreased during the last 5 years from 1.16 to 0.38. The above data show that other emission sources of PCDD/Fs also have a notable environmental impact on the area under direct influence of the MSWI.

Estimating mercury emissions resulting from wildfire in forests of the Western United States.

PubMed

Webster, Jackson P; Kane, Tyler J; Obrist, Daniel; Ryan, Joseph N; Aiken, George R

2016-10-15

Understanding the emissions of mercury (Hg) from wildfires is important for quantifying the global atmospheric Hg sources. Emissions of Hg from soils resulting from wildfires in the Western United States was estimated for the 2000 to 2013 period, and the potential emission of Hg from forest soils was assessed as a function of forest type and soil-heating. Wildfire released an annual average of 3100±1900kg-Hgy(-1) for the years spanning 2000-2013 in the 11 states within the study area. This estimate is nearly 5-fold lower than previous estimates for the study region. Lower emission estimates are attributed to an inclusion of fire severity within burn perimeters. Within reported wildfire perimeters, the average distribution of low, moderate, and high severity burns was 52, 29, and 19% of the total area, respectively. Review of literature data suggests that that low severity burning does not result in soil heating, moderate severity fire results in shallow soil heating, and high severity fire results in relatively deep soil heating (<5cm). Using this approach, emission factors for high severity burns ranged from 58 to 640μg-Hgkg-fuel(-1). In contrast, low severity burns have emission factors that are estimated to be only 18-34μg-Hgkg-fuel(-1). In this estimate, wildfire is predicted to release 1-30gHgha(-1) from Western United States forest soils while above ground fuels are projected to contribute an additional 0.9 to 7.8gHgha(-1). Land cover types with low biomass (desert scrub) are projected to release less than 1gHgha(-1). Following soil sources, fuel source contributions to total Hg emissions generally followed the order of duff>wood>foliage>litter>branches. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface emission determination of volatile organic compounds (VOC) from a closed industrial waste landfill using a self-designed static flux chamber.

PubMed

Gallego, E; Perales, J F; Roca, F J; Guardino, X

2014-02-01

Closed landfills can be a source of VOC and odorous nuisances to their atmospheric surroundings. A self-designed cylindrical air flux chamber was used to measure VOC surface emissions in a closed industrial landfill located in Cerdanyola del Vallès, Catalonia, Spain. The two main objectives of the study were the evaluation of the performance of the chamber setup in typical measurement conditions and the determination of the emission rates of 60 different VOC from that industrial landfill, generating a valuable database that can be useful in future studies related to industrial landfill management. Triplicate samples were taken in five selected sampling points. VOC were sampled dynamically using multi-sorbent bed tubes (Carbotrap, Carbopack X, Carboxen 569) connected to SKC AirCheck 2000 pumps. The analysis was performed by automatic thermal desorption coupled with a capillary gas chromatograph/mass spectrometry detector. The emission rates of sixty VOC were calculated for each sampling point in an effort to characterize surface emissions. To calculate average, minimum and maximum emission values for each VOC, the results were analyzed by three different methods: Global, Kriging and Tributary area. Global and Tributary area methodologies presented similar values, with total VOC emissions of 237 ± 48 and 222 ± 46 g day(-1), respectively; however, Kriging values were lower, 77 ± 17 gd ay(-1). The main contributors to the total emission rate were aldehydes (nonanal and decanal), acetic acid, ketones (acetone), aromatic hydrocarbons and alcohols. Most aromatic hydrocarbon (except benzene, naphthalene and methylnaphthalenes) and aldehyde emission rates exhibited strong correlations with the rest of VOC of their family, indicating a possible common source of these compounds. B:T ratio obtained from the emission rates of the studied landfill suggested that the factors that regulate aromatic hydrocarbon distributions in the landfill emissions are different from the ones from urban areas. Environmental conditions (atmospheric pressure, temperature and relative humidity) did not alter the pollutant emission fluxes. © 2013.

78 FR 52485 - Revisions to the Arizona State Implementation Plan, Maricopa County Area

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-23

...] Revisions to the Arizona State Implementation Plan, Maricopa County Area AGENCY: Environmental Protection... County Area portion of the Arizona State Implementation Plan (SIP). These revisions concern particulate matter (PM) emissions from fugitive dust sources. We are approving local statutes that regulate these...

California's Ozone-Reduction Strategy for Light Duty Vehicles - An Economic Assessment

DOT National Transportation Integrated Search

1996-01-01

California has adopted an aggressive plan to bring the state into compliance with national ambient air quality standards. California's strategy includes strict emission standards on mobile and stationary sourcs and on area sources such as solvents, p...

Low-cost, high-density sensor network for urban emission monitoring: BEACO2N

NASA Astrophysics Data System (ADS)

Kim, J.; Shusterman, A.; Lieschke, K.; Newman, C.; Cohen, R. C.

2017-12-01

In urban environments, air quality is spatially and temporally heterogeneous as diverse emission sources create a high degree of variability even at the neighborhood scale. Conventional air quality monitoring relies on continuous measurements with limited spatial resolution or passive sampling with high-density and low temporal resolution. Either approach averages the air quality information over space or time and hinders our attempts to understand emissions, chemistry, and human exposure in the near-field of emission sources. To better capture the true spatio-temporal heterogeneity of urban conditions, we have deployed a low-cost, high-density air quality monitoring network in San Francisco Bay Area distributed at 2km horizontal spacing. The BErkeley Atmospheric CO2 Observation Network (BEACO2N) consists of approximately 50 sensor nodes, measuring CO2, CO, NO, NO2, O­3, and aerosol. Here we describe field-based calibration approaches that are consistent with the low-cost strategy of the monitoring network. Observations that allow inference of emission factors and identification of specific local emission sources will also be presented.

Contribution of ship emissions to the concentration and deposition of air pollutants in Europe

NASA Astrophysics Data System (ADS)

Aksoyoglu, S.; Prévôt, A. S. H.; Baltensperger, U.

2015-11-01

Emissions from the marine transport sector are one of the least regulated anthropogenic emission sources and contribute significantly to air pollution. Although strict limits were introduced recently for the maximum sulfur content in marine fuels in the SECAs (sulfur emission control areas) and in the EU ports, sulfur emissions outside the SECAs and emissions of other components in all European maritime areas have continued to increase in the last two decades. We have used the air quality model CAMx with and without ship emissions for the year 2006 to determine the effects of international shipping on the annual as well as seasonal concentrations of ozone, primary and secondary components of PM2.5 and the dry and wet deposition of nitrogen and sulfur compounds in Europe. Our results suggest that emissions from international shipping affect the air quality in northern and southern Europe differently and their contributions to the air concentrations vary seasonally. The largest changes in pollutant concentrations due to ship emissions were predicted for summer. Increased concentrations of the primary particle mass were found only along the shipping routes whereas concentrations of the secondary pollutants were affected over a larger area. Concentrations of particulate sulfate increased due to ship emissions in the Mediterranean (up to 60 %), in the English Channel and the North Sea (30-35 %) while increases in particulate nitrate levels were found especially in the north, around the Benelux area (20 %) where there were high NH3 land-based emissions. Our model results showed that not only the atmospheric concentrations of pollutants are affected by ship emissions, but also depositions of nitrogen and sulfur compounds increase significantly along the shipping routes. NOx emissions from the ships especially in the English Channel and the North Sea, cause a decrease in the dry deposition of reduced nitrogen at source regions by moving it from the gas-phase to the particle phase which then contributes to an increase in the wet deposition at coastal areas with higher precipitation. In the western Mediterranean region on the other hand, model results show an increase in the deposition of oxidized nitrogen (mostly HNO3) due to the ship traffic. Dry deposition of SO2 seems to be significant along the shipping routes whereas sulfate wet deposition occurs mainly along the Scandinavian and Adriatic coasts. The results presented in this paper suggest that evolution of NOx emissions from ships and land-based NH3 emissions will play a significant role in the future European air quality.

Ambient ammonia and related amines in and around a mink production facility

USDA-ARS?s Scientific Manuscript database

In areas where ammonia is a significant air pollutant or nuisance concern, knowledge of all potential source locations and strengths is paramount. The USEPA’s 2014 National Emissions Inventory estimates that nearly 80% of the national ammonia emissions are attributable to the agricultural sector an...

Development of a wireless air pollution sensor package for aerial-sampling of emissions

EPA Science Inventory

A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

RESEARCH AREA -- MUNICIPAL WASTE COMBUSTION (AIR POLLUTION TECHNOLOGY BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

EPA Science Inventory

The municipal waste combustion (MWC) program supports the development of revised rules for air pollutant emissions from the MWC source category. Basic research is performed on MWC pollutant formation and control mechanisms for acid gas, trace organic, and trace metal emissions. T...

Major sources of benzene exposure.

PubMed Central

Wallace, L A

1989-01-01

Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population. These sources turn out to be quite different from what had previously been considered the important sources. The most important source of exposure for 50 million smokers is the mainstream smoke from their cigarettes, which accounts for about half of the total population burden of exposure to benzene. Another 20% of nationwide exposure is contributed by various personal activities, such as driving and using attached garages. (Emissions from consumer products, building materials, paints, and adhesives may also be important, although data are largely lacking.) The traditional sources of atmospheric emissions (auto exhaust and industrial emissions) account for only about 20% of total exposure. Environmental tobacco smoke is an important source, accounting for about 5% of total nationwide exposure. A number of sources sometimes considered important, such as petroleum refining operations, petrochemical manufacturing, oil storage tanks, urban-industrial areas, service stations, certain foods, groundwater contamination, and underground gasoline leaks, appear to be unimportant on a nationwide basis. PMID:2477239

Ethane: A Key to Evaluating Natural Gas Industrial Emissions

NASA Astrophysics Data System (ADS)

Yacovitch, T. I.; Herndon, S. C.; Agnese, M.; Roscioli, J. R.; Floerchinger, C. R.; Knighton, W. B.; Pusede, S. E.; Diskin, G. S.; DiGangi, J. P.; Sachse, G. W.; Eichler, P.; Mikoviny, T.; Müller, M.; Wisthaler, A.; Conley, S. A.; Petron, G.

2014-12-01

Airborne and mobile-surface measurements of ethane at 1Hz in the Denver-Julesberg oil and gas production basin in NE Colorado reveal a rich set of emission sources and magnitudes. Although ethane has only a mild influence on hemispheric ozone levels, it is often co-emitted with larger hydrocarbons including hazardous air pollutants (HAPs) and ozone precursors that impact local and regional air quality. Ethane/methane enhancement ratios provide a map of expected emission source types in different areas around greater Denver. Links are drawn between the ethane content of isolated methane emission plumes and the prevalence of concomitant HAP and ozone precursor species. The efficacy of using ethane as a dilution tracer specific to the oil & gas footprint will be demonstrated.

Spatial and temporal patterns of nitrogen isotopic composition of ammonia at U.S. ammonia monitoring network sites

NASA Astrophysics Data System (ADS)

Felix, J. David; Elliott, Emily M.; Gay, David A.

2017-02-01

Ammonia (NH3) emissions and ammonium (NH4+) deposition can have harmful effects on the environment and human health but remain generally unregulated in the U.S. PM2.5 regulations require that an area not exceed an annual average PM2.5 value of 12 μg/m3 (averaged over three years), and since NH3 is a significant precursor to PM2.5 formation these are the closest indirect regulations of NH3 emissions in the U.S. If the U.S. elects to adopt NH3 emission regulations similar to those applied by the European Union, it will be imperative to first adequately quantify NH3 emission sources and transport, and also understand the factors causing varying emissions from each source. To further investigate NH3 emission sources and transport at a regional scale, NH3 was sampled monthly at a subset of nine Ammonia Monitoring Network (AMoN) sites and analyzed for nitrogen isotopic composition of NH3 (δ15N-NH3). The observed δ15N-NH3 values ranged from -42.4 to +7.1‰ with an average of -15.1 ± 9.7. The observed δ15N-NH3 values reported here provide insight into the spatial and temporal trends of the NH3 sources that contribute to ambient [NH3] in the U.S. In regions where agriculture is prevalent (i.e., U.S. Midwest), low and seasonally variable δ15N-NH3 values are observed and are associated with varying agricultural sources. In comparison, rural nonagricultural areas have higher and more seasonally consistent δ15N-NH3 values associated with a constant "natural" (e.g. soil, vegetation, bi-directional flux, ocean) NH3 source. With regards to temporal variation, the peak in U.S. spring agricultural activity (e.g. fertilizer application, livestock waste volatilization) is accompanied by a decrease in δ15N-NH3 values at a majority of the sites, whereas higher δ15N-NH3 values in other seasons could be due to shifting sources (e.g. coal-fired power plants) and/or fractionation scenarios. Fractionation processes that may mask NH3 source signatures are discussed and require further investigation to optimize the utility of the nitrogen isotopic composition to determine NH3 sources and dynamics.

IDENTIFICATION AND CHARACTERIZATION OF FIVE NON- TRADITIONAL SOURCE CATEGORIES: CATASTROPHIC/ACCIDENTAL RELEASES, VEHICLE REPAIR FACILITIES, RECYCLING, PESTICIDE APPLICATION, AND AGRICULTURAL OPERATIONS

EPA Science Inventory

The report gives results of work that is part of EPA's program to identify and characterize emissions sources not currently accounted for by either the existing Aerometric Information Retrieval System (AIRS) or State Implementation Plan (SIP) area source methodologies and to deve...

Evaluation damage threshold of optical thin-film using an amplified spontaneous emission source

NASA Astrophysics Data System (ADS)

Zhou, Qiong; Sun, Mingying; Zhang, Zhixiang; Yao, Yudong; Peng, Yujie; Liu, Dean; Zhu, Jianqiang

2014-10-01

An accurate evaluation method with an amplified spontaneous emission (ASE) as the irradiation source has been developed for testing thin-film damage threshold. The partial coherence of the ASE source results in a very smooth beam profile in the near-field and a uniform intensity distribution of the focal spot in the far-field. ASE is generated by an Nd: glass rod amplifier in SG-II high power laser facility, with pulse duration of 9 ns and spectral width (FWHM) of 1 nm. The damage threshold of the TiO2 high reflection film is 14.4J/cm2 using ASE as the irradiation source, about twice of 7.4 J/cm2 that tested by a laser source with the same pulse duration and central wavelength. The damage area induced by ASE is small with small-scale desquamation and a few pits, corresponding to the defect distribution of samples. Large area desquamation is observed in the area damaged by laser, as the main reason that the non-uniformity of the laser light. The ASE damage threshold leads to more accurate evaluations of the samples damage probability by reducing the influence of hot spots in the irradiation beam. Furthermore, the ASE source has a great potential in the detection of the defect distribution of the optical elements.

Assessment and Optimization of the Accuracy of an Aircraft-Based Technique Used to Quantify Greenhouse Gas Emission Rates from Point Sources

NASA Astrophysics Data System (ADS)

Shepson, P. B.; Lavoie, T. N.; Kerlo, A. E.; Stirm, B. H.

2016-12-01

Understanding the contribution of anthropogenic activities to atmospheric greenhouse gas concentrations requires an accurate characterization of emission sources. Previously, we have reported the use of a novel aircraft-based mass balance measurement technique to quantify greenhouse gas emission rates from point and area sources, however, the accuracy of this approach has not been evaluated to date. Here, an assessment of method accuracy and precision was performed by conducting a series of six aircraft-based mass balance experiments at a power plant in southern Indiana and comparing the calculated CO2 emission rates to the reported hourly emission measurements made by continuous emissions monitoring systems (CEMS) installed directly in the exhaust stacks at the facility. For all flights, CO2 emissions were quantified before CEMS data were released online to ensure unbiased analysis. Additionally, we assess the uncertainties introduced to the final emission rate caused by our analysis method, which employs a statistical kriging model to interpolate and extrapolate the CO2 fluxes across the flight transects from the ground to the top of the boundary layer. Subsequently, using the results from these flights combined with the known emissions reported by the CEMS, we perform an inter-model comparison of alternative kriging methods to evaluate the performance of the kriging approach.

Quantifying the sources of ozone, fine particulate matter, and regional haze in the Southeastern United States.

PubMed

Odman, M Talat; Hu, Yongtao; Russell, Armistead G; Hanedar, Asude; Boylan, James W; Brewer, Patricia F

2009-07-01

A detailed sensitivity analysis was conducted to quantify the contributions of various emission sources to ozone (O3), fine particulate matter (PM2.5), and regional haze in the Southeastern United States. O3 and particulate matter (PM) levels were estimated using the Community Multiscale Air Quality (CMAQ) modeling system and light extinction values were calculated from modeled PM concentrations. First, the base case was established using the emission projections for the year 2009. Then, in each model run, SO2, primary carbon (PC), NH3, NO(x) or VOC emissions from a particular source category in a certain geographic area were reduced by 30% and the responses were determined by calculating the difference between the results of the reduced emission case and the base case. The sensitivity of summertime O3 to VOC emissions is small in the Southeast and ground-level NO(x) controls are generally more beneficial than elevated NO(x) controls (per unit mass of emissions reduced). SO2 emission reduction is the most beneficial control strategy in reducing summertime PM2.5 levels and improving visibility in the Southeast and electric generating utilities are the single largest source of SO2. Controlling PC emissions can be very effective locally, especially in winter. Reducing NH3 emissions is an effective strategy to reduce wintertime ammonium nitrate (NO3NH4) levels and improve visibility; NO(x) emissions reductions are not as effective. The results presented here will help the development of specific emission control strategies for future attainment of the National Ambient Air Quality Standards in the region.

On the methane paradox: Transport from shallow water zones rather than in situ methanogenesis is the major source of CH4 in the open surface water of lakes

NASA Astrophysics Data System (ADS)

Encinas Fernández, Jorge; Peeters, Frank; Hofmann, Hilmar

2016-10-01

Estimates of global methane (CH4) emissions from lakes and the contributions of different pathways are currently under debate. In situ methanogenesis linked to algae growth was recently suggested to be the major source of CH4 fluxes from aquatic systems. However, based on our very large data set on CH4 distributions within lakes, we demonstrate here that methane-enriched water from shallow water zones is the most likely source of the basin-wide mean CH4 concentrations in the surface water of lakes. Consistently, the mean surface CH4 concentrations are significantly correlated with the ratio between the surface area of the shallow water zone and the entire lake, fA,s/t, but not with the total surface area. The categorization of CH4 fluxes according to fA,s/t may therefore improve global estimates of CH4 emissions from lakes. Furthermore, CH4 concentrations increase substantially with water temperature, indicating that seasonally resolved data are required to accurately estimate annual CH4 emissions.

Quantifying the relative contribution of natural gas fugitive emissions to total methane emissions in Colorado, Utah, and Texas using mobile δ13CH4 analysis

NASA Astrophysics Data System (ADS)

Rella, C.; Crosson, E.; Petron, G.; Sweeney, C.; Karion, A.

2013-12-01

Fugitive emissions of methane into the atmosphere are a major concern facing the natural gas production industry. Because methane is more energy-rich than coal per kg of CO2 emitted into the atmosphere, it represents an attractive alternative to coal for electricity generation, provided that the fugitive emissions of methane are kept under control. A key step in assessing these emissions in a given region is partitioning the observed methane emissions between natural gas fugitive emissions and other sources of methane, such as from landfills or agricultural activities. One effective method for assessing the contribution of these different sources is stable isotope analysis, using the δ13CH4 signature to distinguish between natural gas and landfills or ruminants. We present measurements of mobile field δ13CH4 using a spectroscopic stable isotope analyzer based on cavity ringdown spectroscopy, in three intense natural gas producing regions of the United States: the Denver-Julesburg basin in Colorado, the Uintah basin in Utah, and the Barnett Shale in Texas. Mobile isotope measurements of individual sources and in the nocturnal boundary layer have been combined to establish the fraction of the observed methane emissions that can be attributed to natural gas activities. The fraction of total methane emissions in the Denver-Julesburg basin attributed to natural gas emissions is 78 +/- 13%. In the Uinta basin, which has no other significant sources of methane, the fraction is 96% +/- 15%. In addition, results from the Barnett shale are presented, which includes a major urban center (Dallas / Ft. Worth). Methane emissions in this region are spatially highly heterogeneous. Spatially-resolved isotope and concentration measurements are interpreted using a simple emissions model to arrive at an overall isotope ratio for the region. (left panel) Distribution of oil and gas well pads (yellow) and landfills (blue) in the Dallas / Ft. Worth area. Mobile nocturnal measurements of methane are shown in red, indicating a strong degree of source heterogeneity. (right panel) Histogram of individual isotopic source signatures, showing distinct signatures for landfills (red) and oil and gas sources (green).

Source apportionment of fine particulate matter measured in an industrialized coastal urban area of South Texas

NASA Astrophysics Data System (ADS)

Karnae, Saritha; John, Kuruvilla

2011-07-01

Corpus Christi is a growing industrialized urban airshed in South Texas impacted by local emissions and regional transport of fine particulate matter (PM 2.5). Positive matrix factorization (PMF2) technique was used to evaluate particulate matter pollution in the urban airshed by estimating the types of sources and its corresponding mass contributions affecting the measured ambient PM 2.5 levels. Fine particulate matter concentrations by species measured during July 2003 through December 2008 at a PM 2.5 speciation site were used in this study. PMF2 identified eight source categories, of which secondary sulfates were the dominant source category accounting for 30.4% of the apportioned mass. The other sources identified included aged sea salt (18.5%), biomass burns (12.7%), crustal dust (10.1%), traffic (9.7%), fresh sea salt (8.1%), industrial sources (6%), and a co-mingled source of oil combustion & diesel emissions (4.6%). The apportioned PM mass showed distinct seasonal variability between source categories. The PM levels in Corpus Christi were affected by biomass burns in Mexico and Central America during April and May, sub-Saharan dust storms from Africa during the summer months, and a continental haze episode during August and September with significant transport from the highly industrialized areas of Texas and the neighboring states. Potential source contribution function (PSCF) analysis was performed and it identified source regions and the influence of long-range transport of fine particulate matter affecting this urban area.

Atmospheric mercury emissions from mine wastes and surrounding geologically enriched terrains

USGS Publications Warehouse

Gustin, M.S.; Coolbaugh, M.F.; Engle, M.A.; Fitzgerald, B.C.; Keislar, R.E.; Lindberg, S.E.; Nacht, D.M.; Quashnick, J.; Rytuba, J.J.; Sladek, C.; Zhang, H.; Zehner, R.E.

2003-01-01

Waste rock and ore associated with Hg, precious and base metal mining, and their surrounding host rocks are typically enriched in mercury relative to natural background concentrations (<0.1 ??g Hg g-1). Mercury fluxes to the atmosphere from mineralized areas can range from background rates (0-15 ng m-2 h-1) to tens of thousands of ng m-2 h-1. Mercury enriched substrate constitutes a long-term source of mercury to the global atmospheric mercury pool. Mercury emissions from substrate are influenced by light, temperature, precipitation, and substrate mercury concentration, and occur during the day and night. Light-enhanced emissions are driven by two processes: desorption of elemental mercury accumulated at the soil:air interface, and photo reduction of mercury containing phases. To determine the need for and effectiveness of regulatory controls on short-lived anthropogenic point sources the contribution of mercury from geologic non-point sources to the atmospheric mercury pool needs to be quantified. The atmospheric mercury contribution from small areas of mining disturbance with relatively high mercury concentrations are, in general, less than that from surrounding large areas of low levels of mercury enrichment. In the arid to semi-arid west-ern United States volatilization is the primary means by which mercury is released from enriched sites.

A new conceptual model for quantifying transboundary contribution of atmospheric pollutants in the East Asian Pacific rim region.

PubMed

Lai, I-Chien; Lee, Chon-Lin; Huang, Hu-Ching

2016-03-01

Transboundary transport of air pollution is a serious environmental concern as pollutant affects both human health and the environment. Many numerical approaches have been utilized to quantify the amounts of pollutants transported to receptor regions, based on emission inventories from possible source regions. However, sparse temporal-spatial observational data and uncertainty in emission inventories might make the transboundary transport contribution difficult to estimate. This study presents a conceptual quantitative approach that uses transport pathway classification in combination with curve fitting models to simulate an air pollutant concentration baseline for pollution background concentrations. This approach is used to investigate the transboundary transport contribution of atmospheric pollutants to a metropolitan area in the East Asian Pacific rim region. Trajectory analysis categorized pollution sources for the study area into three regions: East Asia, Southeast Asia, and Taiwan cities. The occurrence frequency and transboundary contribution results suggest the predominant source region is the East Asian continent. This study also presents an application to evaluate heavy pollution cases for health concerns. This new baseline construction model provides a useful tool for the study of the contribution of transboundary pollution delivered to receptors, especially for areas deficient in emission inventories and regulatory monitoring data for harmful air pollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

Visualization of NO2 emission sources using temporal and spatial pattern analysis in Asia

NASA Astrophysics Data System (ADS)

Schütt, A. M. N.; Kuhlmann, G.; Zhu, Y.; Lipkowitsch, I.; Wenig, M.

2016-12-01

Nitrogen dioxide (NO2) is an indicator for population density and level of development, but the contributions of the different emission sources to the overall concentrations remains mostly unknown. In order to allocate fractions of OMI NO2 to emission types, we investigate several temporal cycles and regional patterns.Our analysis is based on daily maps of tropospheric NO2 vertical column densities (VCDs) from the Ozone Monitoring Instrument (OMI). The data set is mapped to a high resolution grid by a histopolation algorithm. This algorithm is based on a continuous parabolic spline, producing more realistic smooth distributions while reproducing the measured OMI values when integrating over ground pixel areas.In the resulting sequence of zoom in maps, we analyze weekly and annual cycles for cities, countryside and highways in China, Japan and Korea Republic and look for patterns and trends and compare the derived results to emission sources in Middle Europe and North America. Due to increased heating in winter compared to summer and more traffic during the week than on Sundays, we dissociate traffic, heating and power plants and visualized maps with different sources. We will also look into the influence of emission control measures during big events like the Olympic Games 2008 and the World Expo 2010 as a possibility to confirm our classification of NO2 emission sources.

Organic composition and source apportionment of fine aerosol at Monterrey, Mexico, based on organic markers

NASA Astrophysics Data System (ADS)

Mancilla, Y.; Mendoza, A.; Fraser, M. P.; Herckes, P.

2016-01-01

Primary emissions from anthropogenic and biogenic sources as well as secondary formation are responsible for the pollution levels of ambient air in major urban areas. These sources release fine particles into the air that negatively impact human health and the environment. Organic molecular markers, which are compounds that are unique to specific PM2.5 sources, can be utilized to identify the major emission sources in urban areas. In this study, 43 representative PM2.5 samples, for both daytime and nighttime periods, were built from individual samples collected in an urban site of the Monterrey metropolitan area (MMA) during the spring and fall of 2011 and 2012. The samples were analyzed for organic carbon, elemental carbon, and organic molecular markers. Several diagnostic tools were employed for the preliminary identification of emission sources. Organic compounds for eight compound classes were quantified. The n-alkanoic acids were the most abundant, followed by n-alkanes, wood smoke markers, and levoglucosan/alkenoic acids. Polycyclic aromatic hydrocarbons (PAHs) and hopanes were less abundant. The carbon preference index (0.7-2.6) for n-alkanes indicates a major contribution of anthropogenic and mixed sources during the fall and the spring, respectively. Hopanes levels confirmed the contribution from gasoline and diesel engines. In addition, the contribution of gasoline and diesel vehicle exhaust was confirmed and identified by the PAH concentrations in PM2.5. Diagnostic ratios of PAHs showed emissions from burning coal, wood, biomass, and other fossil fuels. The total PAHs and elemental carbon were correlated (r2 = 0.39-0.70) across the monitoring periods, reinforcing that motor vehicles are the major contributors of PAHs. Cholesterol levels remained constant during the spring and fall, showing evidence of the contribution of meat-cooking operations, while the isolated concentrations of levoglucosan suggested occasional biomass burning events. Finally, source attribution results obtained using the CMB (chemical mass balance) model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5, followed by meat-cooking operations with 31 % The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is only the second study to explore the organic composition and source apportionment of fine organic aerosol based on molecular markers in Mexico and the first for the MMA. Particularly molecular marker were quantified by solvent extraction with dichloromethane, derivatization, and gas chromatography with mass spectrometry (GC/MS).

Detailed investigation of the gamma-ray emission in the vicinity of SNR W28 with Fermi-LAT

DOE PAGES

Hanabata, Y.; Katagiri, H.; Hewitt, J. W.; ...

2014-04-25

Here, we present a detailed investigation of the γ-ray emission in the vicinity of the supernova remnant (SNR) W28 (G6.4–0.1) observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. We detected significant γ-ray emission spatially coincident with TeV sources HESS J1800–240A, B, and C, located outside the radio boundary of the SNR. Their spectra in the 2-100 GeV band are consistent with the extrapolation of the power-law spectra of the TeV sources. We also identified a new source of GeV emission, dubbed Source W, which lies outside the boundary of TeV sources and coincides withmore » radio emission from the western part of W28. All of the GeV γ-ray sources overlap with molecular clouds in the velocity range from 0 to 20 km s –1. Under the assumption that the γ-ray emission toward HESS J1800–240A, B, and C comes from π 0 decay due to the interaction between the molecular clouds and cosmic rays (CRs) escaping from W28, they can be naturally explained by a single model in which the CR diffusion coefficient is smaller than the theoretical expectation in the interstellar space. Furthermore, we constrain the total energy of the CRs escaping from W28 through the same modeling to be larger than ~2 × 10 49 erg. The emission from Source W can also be explained with the same CR escape scenario.« less

Nitrogen source and placement effects on soil nitrous oxide emissions from no-till corn.

PubMed

Halvorson, Ardell D; Del Grosso, Stephen J

2012-01-01

A nitrogen (N) source comparison study was conducted to further evaluate the effects of inorganic N source and placement on growing-season and non-crop period soil nitrous oxide (NO). Commercially available controlled-release N fertilizers were evaluated for their potential to reduce NO emissions from a clay loam soil compared with conventionally used granular urea and urea-ammonium nitrate (UAN) fertilizers in an irrigated no-till (NT) corn ( L.) production system. Controlled-release N fertilizers evaluated were: a polymer-coated urea (ESN), stabilized urea (SuperU), and UAN+AgrotainPlus (SuperU and AgrotainPlus contain nitrification and urease inhibitors). Each N source was surface band applied (202 kg N ha) near the corn row at emergence and watered into the soil the next day. Subsurface banded ESN (ESNssb) and check (no N applied) treatments were included. Nitrous oxide fluxes were measured during two growing seasons and after harvest using static, vented chambers. All N sources had significantly lower growing-season NO emissions than granular urea (0.7% of applied N), with UAN+AgrotainPlus (0.2% of applied N) and ESN (0.3% of applied N) having lower emissions than UAN (0.4% of applied N). Similar trends were observed when expressing NO emissions on a grain yield and N uptake basis. Corn grain yields were not different among N sources but were greater than the check. Selection of N fertilizer source can be a mitigation practice for reducing NO emissions in NT, irrigated corn in semiarid areas. In our study, UAN+AgrotainPlus consistently had the lowest level of NO emissions with no yield loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Localizing sources of acoustic emission during the martensitic transformation

NASA Astrophysics Data System (ADS)

Niemann, R.; Kopeček, J.; Heczko, O.; Romberg, J.; Schultz, L.; Fähler, S.; Vives, E.; Mañosa, L.; Planes, A.

2014-06-01

Acoustic avalanches are a general feature of solids under stress, e.g., evoked by external compression or arising from internal processes like martensitic phase transformations. From integral measurements, it is usually concluded that nucleation, phase boundary pinning, or interface incompatibilities during this first-order phase transition all may generate acoustic emission. This paper studies the local sources of acoustic emission to enlight the microscopic mechanisms. From two-dimensional spatially resolved acoustic emission measurement and simultaneous optical observation of the surface, we can identify microstructural events at the phase boundary that lead to acoustic emission. A resolution in the 100-μm range was reached for the location of acoustic emission sources on a coarse-grained Ni-Mn-Ga polycrystal. Both, the acoustic activity and the size distribution of the microstructural transformation events, exhibit power-law behavior. The origin of the acoustic emission are elastically incompatible areas, such as differently oriented martensitic plates that meet each other, lamellae growing up to grain boundaries, and grain boundaries in proximity to transforming grains. Using this result, we propose a model to explain the decrease of the critical exponent under a mechanical stress or magnetic field.

A small subset of protected areas are a highly significant source of carbon emissions

PubMed Central

Collins, Murray B.; Mitchard, Edward T. A.

2017-01-01

Protected areas (PAs) aim to protect multiple ecosystem services. However, not all are well protected. For the first time, using published carbon and forest loss maps, we estimate carbon emissions in large forest PAs in tropical countries (N = 2018). We found 36 ± 16 Pg C stored in PA trees, representing 14.5% of all tropical forest biomass carbon. However the PAs lost forest at a mean rate of 0.18% yr−1 from 2000–2012. Lower protection status areas experienced higher forest losses (e.g. 0.39% yr−1 in IUCN cat III), yet even highest status areas lost 0.13% yr−1 (IUCN Cat I). Emissions were not evenly distributed: 80% of emissions derived from 8.3% of PAs (112 ± 49.5 Tg CO2 yr−1; n = 171). Unsurprisingly the largest emissions derived from PAs that started with the greatest total forest area; accounting for starting forest area and relating that to carbon lost using a linear model (r2 = 0.41), we found 1.1% outlying PAs (residuals >2σ; N = 23), representing 1.3% of the total PA forest area, yet causing 27.3% of all PA emissions. These results suggest PAs have been a successful means of protecting biomass carbon, yet a subset causing a disproportionately high share of emissions should be an urgent priority for management interventions. PMID:28186155

Spatial and temporal disaggregation of transport-related carbon dioxide emissions in Bogota - Colombia

NASA Astrophysics Data System (ADS)

Hernandez-Gonzalez, L. A.; Jimenez Pizarro, R.; Néstor Y. Rojas, N. Y.

2011-12-01

As a result of rapid urbanization during the last 60 years, 75% of the Colombian population now lives in cities. Urban areas are net sources of greenhouse gases (GHG) and contribute significantly to national GHG emission inventories. The development of scientifically-sound GHG mitigation strategies require accurate GHG source and sink estimations. Disaggregated inventories are effective mitigation decision-making tools. The disaggregation process renders detailed information on the distribution of emissions by transport mode, and the resulting a priori emissions map allows for optimal definition of sites for GHG flux monitoring, either by eddy covariance or inverse modeling techniques. Fossil fuel use in transportation is a major source of carbon dioxide (CO2) in Bogota. We present estimates of CO2 emissions from road traffic in Bogota using the Intergovernmental Panel on Climate Change (IPCC) reference method, and a spatial and temporal disaggregation method. Aggregated CO2 emissions from mobile sources were estimated from monthly and annual fossil fuel (gasoline, diesel and compressed natural gas - CNG) consumption statistics, and estimations of bio-ethanol and bio-diesel use. Although bio-fuel CO2 emissions are considered balanced over annual (or multi-annual) agricultural cycles, we included them since CO2 generated by their combustion would be measurable by a net flux monitoring system. For the disaggregation methodology, we used information on Bogota's road network classification, mean travel speed and trip length for each vehicle category and road type. The CO2 emission factors were taken from recent in-road measurements for gasoline- and CNG-powered vehicles and also estimated from COPERT IV. We estimated emission factors for diesel from surveys on average trip length and fuel consumption. Using IPCC's reference method, we estimate Bogota's total transport-related CO2 emissions for 2008 (reference year) at 4.8 Tg CO2. The disaggregation method estimation is 16% lower, mainly due to uncertainty in activity factors. With only 4% of Bogota's fleet, diesel use accounts for 42% of the CO2 emissions. The emissions are almost evenly shared between public (9% of the fleet) and private transport. Peak emissions occur at 8 a.m. and 6 p.m. with maximum values over a densely industrialized area at the northwest of Bogota. This investigation allowed estimating the relative contribution of fuel and vehicle categories to spatially- and temporally-resolved CO2 emissions. Fuel consumption time series indicate a near-stabilization trend on energy consumption for transportation, which is unexpected taking into account the sustained economic and vehicle fleet growth in Bogota. The comparison of the disaggregation methodology with the IPCC methodology contributes to the analysis of possible error sources on activity factor estimations. This information is very useful for uncertainty estimation and adjustment of primary air pollutant emissions inventories.

EMISSIONS PROFILE CHARACTERIZATION OF LAKE MICHIGAN POLLUTANT SOURCES - PART II

EPA Science Inventory

The southern Lake Michigan area continues to experience poor air quality despite the implementation of many measures to control particulate matter, ozone and toxic pollutants. Fortunately, the ambient atmosphere holds clues to these sources and their contributions to urban pollut...

Mobile Air Quality Monitoring for Local High-Resolution Characterization of Vehicle-Sourced Criteria Pollutant

DOT National Transportation Integrated Search

2017-06-19

Transportation-related emissions are a major source of air pollution in many urban areas. Human exposure to this pollution is related to their proximity to major roadways, yet federal and state Environmental Protection Agencies (EPAs) conduct regulat...

Near-source air pollution and mitigation strategies

EPA Science Inventory

Abstract. Local-scale air pollution impact is of concern for populations located in close proximity to transit sources, including highway, port, rail, and other areas of concentrated diesel emissions. Previous near-road air monitoring research has prompted the U.S. EPA to implem...

Photochemical processing of diesel fuel emissions as a large secondary source of isocyanic acid (HNCO)

NASA Astrophysics Data System (ADS)

Link, M. F.; Friedman, B.; Fulgham, R.; Brophy, P.; Galang, A.; Jathar, S. H.; Veres, P.; Roberts, J. M.; Farmer, D. K.

2016-04-01

Isocyanic acid (HNCO) is a well-known air pollutant that affects human health. Biomass burning, smoking, and combustion engines are known HNCO sources, but recent studies suggest that secondary production in the atmosphere may also occur. We directly observed photochemical production of HNCO from the oxidative aging of diesel exhaust during the Diesel Exhaust Fuel and Control experiments at Colorado State University using acetate ionization time-of-flight mass spectrometry. Emission ratios of HNCO were enhanced, after 1.5 days of simulated atmospheric aging, from 50 to 230 mg HNCO/kg fuel at idle engine operating conditions. Engines operated at higher loads resulted in less primary and secondary HNCO formation, with emission ratios increasing from 20 to 40 mg HNCO/kg fuel under 50% load engine operating conditions. These results suggest that photochemical sources of HNCO could be more significant than primary sources in urban areas.

Contribution of ship emissions to the concentration and deposition of air pollutants in Europe

NASA Astrophysics Data System (ADS)

Aksoyoglu, Sebnem; Baltensperger, Urs; Prévôt, André S. H.

2016-02-01

Emissions from the marine transport sector are one of the least-regulated anthropogenic emission sources and contribute significantly to air pollution. Although strict limits were introduced recently for the maximum sulfur content in marine fuels in the SECAs (sulfur emission control areas) and in EU ports, sulfur emissions outside the SECAs and emissions of other components in all European maritime areas have continued to increase in the last two decades. We have used the air quality model CAMx (Comprehensive Air Quality Model with Extensions) with and without ship emissions for the year 2006 to determine the effects of international shipping on the annual as well as seasonal concentrations of ozone, primary and secondary components of PM2.5, and the dry and wet deposition of nitrogen and sulfur compounds in Europe. The largest changes in pollutant concentrations due to ship emissions were predicted for summer. Concentrations of particulate sulfate increased due to ship emissions in the Mediterranean (up to 60 %), the English Channel and the North Sea (30-35 %), while increases in particulate nitrate levels were found especially in the north, around the Benelux area (20 %), where there were high NH3 land-based emissions. Our model results showed that not only are the atmospheric concentrations of pollutants affected by ship emissions, but also depositions of nitrogen and sulfur compounds increase significantly along the shipping routes. NOx emissions from the ships, especially in the English Channel and the North Sea, cause a decrease in the dry deposition of reduced nitrogen at source regions by moving it from the gas phase to the particle phase which then contributes to an increase in the wet deposition at coastal areas with higher precipitation. In the western Mediterranean region, on the other hand, model results show an increase in the deposition of oxidized nitrogen (mostly HNO3) due to the ship traffic. Dry deposition of SO2 seems to be significant along the shipping routes, whereas sulfate wet deposition occurs mainly along the Scandinavian and Adriatic coasts. The results presented in this paper suggest that evolution of NOx emissions from ships and land-based NH3 emissions will play a significant role in future European air quality.

Mapping Atmospheric Ammonia Emissions Using a Mobile Quantum Cascade Laser-based Open-path Sensor

NASA Astrophysics Data System (ADS)

Sun, K.; Tao, L.; Miller, D. J.; Khan, M. A.; Zondlo, M. A.

2012-12-01

Ammonia (NH3) is a key precursor to atmospheric fine particulate matter, with strong implications for regional air quality and global climate change. Despite the importance of atmospheric ammonia, its spatial/temporal variation is poorly characterized, and the knowledge of its sources, sinks, and transport is severely limited. Existing measurements suggest that traffic exhaust may provide significant amounts of ammonia in urban areas, which cause greater impacts on particulate matter formation and urban air quality. To capture the spatial and temporal variation of ammonia emissions, a portable, low power sensor with high time resolution is necessary. We have developed a portable open-path ammonia sensor with a detection limit of 0.5 ppbv ammonia for 1 s measurements. The sensor has a power consumption of about 60 W and is capable of running on a car battery continuously for 24 hours. An additional laser has been coupled to the sensor to yield concurrent N2O and CO measurements as tracers for determining various sources. The overall sensor prototype fits on a 60 cm × 20 cm aluminum breadboard. Roadside measurements indicated NH3/CO emission ratios of 4.1±5.4 ppbv/ppmv from a fleet of 320 vehicles, which agree with existing on-ramp measurements. Urban measurements in the Baltimore and Washington, DC metropolitan areas have shown significant ammonia mixing ratios concurrent with carbon monoxide levels from the morning and evening rush hours. On-road measurements of our open-path sensor have also been performed continuously from the Midwest to Princeton, NJ including urban areas such as Pittsburgh, tunnels, and relatively clean conditions. The emission ratios of ammonia against CO and/or CO2 help identify the sources and amounts of both urban and agricultural ammonia emissions. Preliminary data from both spatial mapping, monitoring, and vehicle exhaust measurements suggest that urban ammonia emissions from fossil fuel combustion are significant and may provide an unrecognized source in the atmospheric ammonia budget. Ongoing efforts include spatial mapping of ammonia and other tracers in the New York City and Philadelphia metropolitan areas. Further comparison with TES satellite ammonia retrieval will help to put the measurements into a larger geographical and temporal context.

Methane source identification in Boston, Massachusetts using isotopic and ethane measurements

NASA Astrophysics Data System (ADS)

Down, A.; Jackson, R. B.; Plata, D.; McKain, K.; Wofsy, S. C.; Rella, C.; Crosson, E.; Phillips, N. G.

2012-12-01

Methane has substantial greenhouse warming potential and is the principle component of natural gas. Fugitive natural gas emissions could be a significant source of methane to the atmosphere. However, the cumulative magnitude of natural gas leaks is not yet well constrained. We used a combination of point source measurements and ambient monitoring to characterize the methane sources in the Boston urban area. We developed distinct fingerprints for natural gas and multiple biogenic methane sources based on hydrocarbon concentration and isotopic composition. We combine these data with periodic measurements of atmospheric methane and ethane concentration to estimate the fractional contribution of natural gas and biogenic methane sources to the cumulative urban methane flux in Boston. These results are used to inform an inverse model of urban methane concentration and emissions.

Propane and butane emission sources to ambient air of Mexico City metropolitan area.

PubMed

Jaimes, L; Sandoval, J

2002-04-22

Samples of volatile organic compounds (VOCs) were collected in a smog chamber in order to determine whether automotive exhausts or LP Gas emissions play a greater role in the source of propane and butane, which affect ozone formation and other pollutants in the ambient air of the Mexico City metropolitan area (MCMA). These samples were collected in April 1995 during mornings and evenings. The testing methodology used for measuring exhaust emission were FTP or EPA-74 tests, and SHED type tests were also conducted in order to evaluate evaporative emissions. The finding from analysis of the VOCs collected in the morning demonstrate that in the atmosphere, propane concentrations are higher than that of butane but the reverse in evaporative and exhaust emissions, with the concentration of propane lower than that of butane. Our conclusion is that most of C3 and C4 in the ambient air comes from LP gas and not vehicle exhaust or evaporative emission, due to the higher levels of propane than butane in its formulation. The analysis of VOCs also indicates that although the conversion (in the smog chamber) of alkanes is low during the day, due to the high initial concentration, their contribution in the reaction mechanism to produce ozone can be appreciable.

Source apportionment of fine particles and its chemical components over the Yangtze River Delta, China during a heavy haze pollution episode

NASA Astrophysics Data System (ADS)

Li, L.; An, J. Y.; Zhou, M.; Yan, R. S.; Huang, C.; Lu, Q.; Lin, L.; Wang, Y. J.; Tao, S. K.; Qiao, L. P.; Zhu, S. H.; Chen, C. H.

2015-12-01

An extremely high PM2.5 pollution episode occurred over the eastern China in January 2013. In this paper, the particulate matter source apportionment technology (PSAT) method coupled within the Comprehensive air quality model with extensions (CAMx) is applied to study the source contributions to PM2.5 and its major components at six receptors (Urban Shanghai, Chongming, Dianshan Lake, Urban Suzhou, Hangzhou and Zhoushan) in the Yangtze River Delta (YRD) region. Contributions from 4 source areas (including Shanghai, South Jiangsu, North Zhejiang and Super-region) and 9 emission sectors (including power plants, industrial boilers and kilns, industrial processing, mobile source, residential, volatile emissions, dust, agriculture and biogenic emissions) to PM2.5 and its major components (sulfate, nitrate, ammonia, organic carbon and elemental carbon) at the six receptors in the YRD region are quantified. Results show that accumulation of local pollution was the largest contributor during this air pollution episode in urban Shanghai (55%) and Suzhou (46%), followed by long-range transport (37% contribution to Shanghai and 44% to Suzhou). Super-regional emissions play an important role in PM2.5 formation at Hangzhou (48%) and Zhoushan site (68%). Among the emission sectors contributing to the high pollution episode, the major source categories include industrial processing (with contributions ranging between 12.7 and 38.7% at different receptors), combustion source (21.7-37.3%), mobile source (7.5-17.7%) and fugitive dust (8.4-27.3%). Agricultural contribution is also very significant at Zhoushan site (24.5%). In terms of the PM2.5 major components, it is found that industrial boilers and kilns are the major source contributor to sulfate and nitrate. Volatile emission source and agriculture are the major contributors to ammonia; transport is the largest contributor to elemental carbon. Industrial processing, volatile emissions and mobile source are the most significant contributors to organic carbon. Results show that the Yangtze River Delta region should focus on the joint pollution control of industrial processing, combustion emissions, mobile source emissions, and fugitive dust. Regional transport of air pollution among the cities are prominent, and the implementation of regional joint prevention and control of air pollution will help to alleviate fine particulate matter concentrations under heavy pollution case significantly.

Primary sources of PM2.5 organic aerosol in an industrial Mediterranean city, Marseille

NASA Astrophysics Data System (ADS)

El Haddad, I.; Marchand, N.; Wortham, H.; Piot, C.; Besombes, J.-L.; Cozic, J.; Chauvel, C.; Armengaud, A.; Robin, D.; Jaffrezo, J.-L.

2011-03-01

Marseille, the most important port of the Mediterranean Sea, represents a challenging case study for source apportionment exercises, combining an active photochemistry and multiple emission sources, including fugitive emissions from industrial sources and shipping. This paper presents a Chemical Mass Balance (CMB) approach based on organic markers and metals to apportion the primary sources of organic aerosol in Marseille, with a special focus on industrial emissions. Overall, the CMB model accounts for the major primary anthropogenic sources including motor vehicles, biomass burning and the aggregate emissions from three industrial processes (heavy fuel oil combustion/shipping, coke production and steel manufacturing) as well as some primary biogenic emissions. This source apportionment exercise is well corroborated by 14C measurements. Primary OC estimated by the CMB accounts on average for 22% of total OC and is dominated by the vehicular emissions that contribute on average for 17% of OC mass concentration (vehicular PM contributes for 17% of PM2.5). Even though industrial emissions contribute only 2.3% of the total OC (7% of PM2.5), they are associated with ultrafine particles (Dp<80 nm) and high concentrations of Polycyclic Aromatic Hydrocarbons (PAH) and heavy metals such as Pb, Ni and V. On one hand, given that industrial emissions governed key primary markers, their omission would lead to substantial uncertainties in the CMB analysis performed in areas heavily impacted by such sources, hindering accurate estimation of non-industrial primary sources and secondary sources. On the other hand, being associated with bursts of submicron particles and carcinogenic and mutagenic components such as PAH, these emissions are most likely related with acute ill-health outcomes and should be regulated despite their small contributions to OC. Another important result is the fact that 78% of OC mass cannot be attributed to the major primary sources and, thus, remains un-apportioned. We have consequently critically investigated the uncertainties underlying our CMB apportionments. While we have provided some evidence for photochemical decay of hopanes, this decay does not appear to significantly alter the CMB estimates of the total primary OC. Sampling artifacts and unaccounted primary sources also appear to marginally influence the amount of un-apportioned OC. Therefore, this significant amount of un-apportioned OC is mostly attributed to secondary organic carbon that appears to be the major component of OC during the whole period of study.

Modeling study of natural emissions, source apportionment, and emission control of atmospheric mercury

NASA Astrophysics Data System (ADS)

Shetty, Suraj K.

Mercury (Hg) is a toxic pollutant and is important to understand its cycling in the environment. In this dissertation, a number of modeling investigations were conducted to better understand the emission from natural surfaces, the source-receptor relationship of the emissions, and emission reduction of atmospheric mercury. The first part of this work estimates mercury emissions from vegetation, soil and water surfaces using a number of natural emission processors and detailed (LAI) Leaf Area Index data from GIS (Geographic Information System) satellite products. East Asian domain was chosen as it contributes nearly 50% of the global anthropogenic mercury emissions into the atmosphere. The estimated annual natural mercury emissions (gaseous elemental mercury) in the domain are 834 Mg yr-1 with 462 Mg yr-1 contributing from China. Compared to anthropogenic sources, natural sources show greater seasonal variability (highest in simmer). The emissions are significant, sometimes dominant, contributors to total mercury emission in the regions. The estimates provide possible explanation for the gaps between the anthropogenic emission estimates based on activity data and the emission inferred from field observations in the regions. To understand the contribution of domestic emissions to mercury deposition in the United States, the second part of the work applies the mercury model of Community Multi-scale Air Quality Modeling system (CMAQ-Hg v4.6) to apportion the various emission sources attributing to the mercury wet and dry deposition in the 6 United States receptor regions. Contributions to mercury deposition from electric generating units (EGU), iron and steel industry (IRST), industrial point sources excluding EGU and IRST (OIPM), the remaining anthropogenic sources (RA), natural processes (NAT), and out-of-boundary transport (BC) in domain was estimated. The model results for 2005 compared reasonably well to field observations made by MDN (Mercury Deposition Network) and CAMNet (Canadian Atmospheric Mercury Measurement Network). The model estimated a total deposition of 474 Mg yr-1 to the CONUS (Contiguous United States) domain, with two-thirds being dry deposited. Reactive gaseous mercury contributed the most to 60% of deposition. Emission speciation distribution is a key factor for local deposition as contribution from large point sources can be as high as 75% near (< 100 km) the emission sources, indicating that emission reduction may result in direct deposition decrease near the source locations. Among the sources, BC contributes to about 68% to 91% of total deposition. Excluding the BC's contribution, EGU contributes to nearly 50% of deposition caused by CONUS emissions in the Northeast, Southeast and East Central regions, while emissions from natural processes are more important in the Pacific and West Central regions (contributing up to 40% of deposition). The modeling results implies that implementation of the new emission standards proposed by USEPA (United States Environmental Protection Agency) would significantly benefit regions that have larger contributions from EGU sources. Control of mercury emissions from coal combustion processes has attracted great attention due to its toxicity and the emission-control regulations and has lead to advancement in state-of-the-art control technologies that alleviate the impact of mercury on ecosystem and human health. This part of the work applies a sorption model to simulate adsorption of mercury in flue gases, onto a confined-bed of activated carbon. The model's performances were studied at various flue gas flow rates, inlet mercury concentrations and adsorption bed temperatures. The process simulated a flue gas, with inlet mercury concentration of 300 ppb, entering at a velocity of 0.3 m s-1 from the bottom into a fixed bed (inside bed diameter of 1 m and 3 m bed height; bed temperature of 25 °C) of activated carbon (particle size of 0.004 m with density of 0.5 g cm-3 and surface area of 90.25 cm2 g -1). The model result demonstrated that a batch of activated carbon bed was capable of controlling mercury emission for approximately 275 days after which further mercury uptake starts to decrease till it reaches about 500 days when additional control ceases. An increase in bed temperature significantly reduces mercury sorption capacity of the activated carbon. Increase in flue gas flow rate may result in faster consumption of sorption capacity initially but at a later stage, the sorption rate decreases due to reduced sorption capacity. Thus, overall sorption rate remains unaffected. The activated carbon's effective life (time to reach saturation) is not affected by inlet mercury concentration, implying that the designing and operation of a mercury sorption process can be done independently. The results provide quantitative indication for designing efficient confined-bed process to remove mercury from flue gases.

Development of Standardized Mobile Tracer Correlation Approach for Large Area Emission Measurements (DRAFT UNDER EPA REVIEW)

NASA Astrophysics Data System (ADS)

Foster-wittig, T. A.; Thoma, E.; Green, R.; Hater, G.; Swan, N.; Chanton, J.

2013-12-01

Improved understanding of air emissions from large area sources such as landfills, waste water ponds, open-source processing, and agricultural operations is a topic of increasing environmental importance. In many cases, the size of the area source, coupled with spatial-heterogeneity, make direct (on-site) emission assessment difficult; methane emissions, from landfills for example, can be particularly complex [Thoma et al, 2009]. Recently, whole-facility (remote) measurement approaches based on tracer correlation have been utilized [Scheutz et al, 2011]. The approach uses a mobile platform to simultaneously measure a metered-release of a conservative gas (the tracer) along with the target compound (methane in the case of landfills). The known-rate tracer release provides a measure of atmospheric dispersion at the downwind observing location allowing the area source emission to be determined by a ratio calculation [Green et al, 2010]. Although powerful in concept, the approach has been somewhat limited to research applications due to the complexities and cost of the high-sensitivity measurement equipment required to quantify the part-per billion levels of tracer and target gas at kilometer-scale distances. The advent of compact, robust, and easy to use near-infrared optical measurement systems (such as cavity ring down spectroscopy) allow the tracer correlation approach to be investigated for wider use. Over the last several years, Waste Management Inc., the U.S. EPA, and collaborators have conducted method evaluation activities to determine the viability of a standardized approach through execution of a large number of field measurement trials at U.S. landfills. As opposed to previous studies [Scheutz et al, 2011] conducted at night (optimal plume transport conditions), the current work evaluated realistic use-scenarios; these scenarios include execution by non-scientist personnel, daylight operation, and full range of atmospheric condition (all plume transport conditions). The trials tested a novel tracer gas (acetylene), chosen for its performance and cost characteristics. This presentation will summarize method development activities for the field test trials (107 test days, with repeat measurements at 14 separate landfill sites). In addition to a brief description of the measurement technology, the method performance will be described, and primary data quality indicators and use conditions will be explored. Because measurements were taken under daylight and a variety of atmospheric conditions, the range of distance and wind conditions allows us to make conclusions about the strengths and limitations of the method. This enables us to show when and where it is possible to make a quality measurement using this technique and therefore develop a standardized method for large area emission measurements. Green, R. et al (2010). 'Methane Emission Measured at Two California Landfills by OTM-10 and an Acetylene Tracer Method.' Global Waste Management Symposium. San Antonio, Texas. Scheutz, C. et al. (2011). 'Quantification of multiple methane emission sources at landfills using a double tracer technique." Waste Management 31(5): 1009-1017. Thoma, E., et al (2009). 'Development of EPA OTM 10 for landfill applications." Journal of Environmental Engineering 136(8): 769-776.

Underlying Ecosystem Methane Emissions Exceed Cattle-Derived Methane from Subtropical Lowland Pastures.

NASA Astrophysics Data System (ADS)

Chamberlain, S. D.; Sparks, J. P.

2014-12-01

Grazing cattle are a major methane (CH4) source from pasture ecosystems, however the underlying landscape is a potentially significant CH4 source that has received far less attention. Ecosystem surface emissions of CH4 are poorly quantified, vary widely across time and space, and are easily underestimated if emission hotspots or episodic fluxes are overlooked. We used static chambers, eddy covariance, and mobile cavity-ringdown spectrometry surveys to quantify spatially and temporally variable CH4 emissions from subtropical lowland pastures. We conclude emissions from soil and standing water are the dominant CH4 source, and cattle were responsible for only 13% of annual CH4emissions. The ecosystem emit 33.8 ± 2.2 g CH4 m-2 yr-1, however surface CH4 emissions were highly variable in both time and space. Seasonal flooding of pastures and low-lying landforms (canals, ditches, wetlands) drove high magnitude CH4 emissions. We observed large CH4 emissions from wetlands and, to a lesser extent, the entire landscape during the wet season. In contrast, during the dry season there was no appreciable CH4 accumulation in pastures when cattle were not present, and canals, which comprise 1.7% of the total land area, were responsible 97.7 % of dry season emissions. Ecosystem CH4 fluxes, measured by eddy covariance, varied seasonally and positively correlated to soil and air temperature, topsoil water content, and water table depth. Our work is the first to use mobile spectrometers to map biogenic CH4 emissions at the landscape scale, and demonstrates that soils and water are a strong pasture CH4 source that must be considered in addition to cattle emissions.

Source apportionment of VOCs in the Los Angeles area using positive matrix factorization

NASA Astrophysics Data System (ADS)

Brown, Steven G.; Frankel, Anna; Hafner, Hilary R.

Eight 3-h speciated hydrocarbon measurements were collected daily by the South Coast Air Quality Management District (SCAQMD) as part of the Photochemical Assessment Monitoring Stations (PAMS) program during the summers of 2001-03 at two sites in the Los Angeles air basin, Azusa and Hawthorne. Over 30 hydrocarbons from over 500 samples at Azusa and 600 samples at Hawthorne were subsequently analyzed using the multivariate receptor model positive matrix factorization (PMF). At Azusa and Hawthorne, five and six factors were identified, respectively, with a good comparison between predicted and measured mass. At Azusa, evaporative emissions (a median of 31% of the total mass), motor vehicle exhaust (22%), liquid/unburned gasoline (27%), coatings (17%), and biogenic emissions (3%) factors were identified. Factors identified at Hawthorne were evaporative emissions (a median of 34% of the total mass), motor vehicle exhaust (24%), industrial process losses (15%), natural gas (13%), liquid/unburned gasoline (13%), and biogenic emissions (1%). Together, the median contribution from mobile source-related factors (exhaust, evaporative emissions, and liquid/unburned gasoline) was 80% and 71% at Azusa and Hawthorne, respectively, similar to previous source apportionment results using the chemical mass balance (CMB) model. There is a difference in the distribution among mobile source factors compared to the CMB work, with an increase in the contribution from evaporative emissions, though the cause (changes in emissions or differences between models) is unknown.

On-line Field Measurements of Speciated PM1 Emission Factors from Common South Asian Combustion Sources

NASA Astrophysics Data System (ADS)

DeCarlo, P. F.; Goetz, J. D.; Giordano, M.; Stockwell, C.; Maharjan, R.; Adhikari, S.; Bhave, P.; Praveen, P. S.; Panday, A. K.; Jayarathne, T. S.; Stone, E. A.; Yokelson, R. J.

2017-12-01

Characterization of aerosol emissions from prevalent but under sampled combustion sources in South Asia was performed as part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) in April 2015. Targeted emission sources included cooking stoves with a variety of solid fuels, brick kilns, garbage burning, crop-residue burning, diesel irrigation pumps, and motorcycles. Real-time measurements of submicron non-refractory particulate mass concentration and composition were obtained using an Aerodyne mini Aerosol Mass Spectrometer (mAMS). Speciated PM1 mass emission factors were calculated for all particulate species (e.g. organics, sulfates, nitrates, chlorides, ammonium) and for each source type using the carbon mass balance approach. Size resolved emission factors were also acquired using a novel high duty cycle particle time-of-flight technique (ePTOF). Black carbon and brown carbon absorption emission factors and absorption Angström exponents were measured using filter loading and scattering corrected attenuation at 370 nm and 880 nm with a dual spot aethalometer (Magee Scientific AE-33). The results indicate that open garbage burning is a strong emitter of organic aerosol, black carbon, and internally mixed particle phase hydrogen chloride (HCl). Emissions of HCl were attributed to the presence chlorinated plastics. The primarily coal fired brick kilns were found to be large emitters of sulfate but large differences in the organic and light absorbing component of emissions were observed between the two kiln types investigated (technologically advanced vs. traditional). These results, among others, bring on-line and field-tested aerosol emission measurements to an area of atmoshperic research dominated by off-line or laboratory based measurements.

Effectiveness evaluation of temporary emission control action in 2016 in winter in Shijiazhuang, China

NASA Astrophysics Data System (ADS)

Liu, Baoshuang; Cheng, Yuan; Zhou, Ming; Liang, Danni; Dai, Qili; Wang, Lu; Jin, Wei; Zhang, Lingzhi; Ren, Yibin; Zhou, Jingbo; Dai, Chunling; Xu, Jiao; Wang, Jiao; Feng, Yinchang; Zhang, Yufen

2018-05-01

To evaluate the environmental effectiveness of the control measures for atmospheric pollution in Shijiazhuang, China, a large-scale controlling experiment for emission sources of atmospheric pollutants (i.e. a temporary emission control action, TECA) was designed and implemented during 1 November 2016 to 9 January 2017. Compared to the no-control action and heating period (NCAHP), under unfavourable meteorological conditions, the mean concentrations of PM2.5, PM10, SO2, NO2, and chemical species (Si, Al, Ca2+, Mg2+) in PM2.5 during the control action and heating period (CAHP) still decreased by 8, 8, 5, 19, 30.3, 4.5, 47.0, and 45.2 %, respectively, indicating that the control measures for atmospheric pollution were effective. The effects of control measures in suburbs were better than those in urban area, especially for the control effects of particulate matter sources. The control effects for emission sources of carbon monoxide (CO) were not apparent during the TECA period, especially in suburbs, likely due to the increasing usage of domestic coal in suburbs along with the temperature decreasing.The results of positive matrix factorization (PMF) analysis showed that crustal dust, secondary sources, vehicle emissions, coal combustion and industrial emissions were main PM2.5 sources. Compared to the whole year (WY) and the no-control action and no-heating period (NCANHP), the contribution concentrations and proportions of coal combustion to PM2.5 increased significantly during other stages of the TECA period. The contribution concentrations and proportions of crustal dust and vehicle emissions to PM2.5 decreased noticeably during the CAHP compared to other stages of the TECA period. The contribution concentrations and proportions of industrial emissions to PM2.5 during the CAHP decreased noticeably compared to the NCAHP. The pollutants' emission sources during the CAHP were in effective control, especially for crustal dust and vehicles. However, the necessary coal heating for the cold winter and the unfavourable meteorological conditions had an offset effect on the control measures for emission sources to some degree. The results also illustrated that the discharge of pollutants might still be enormous even under such strict control measures.The backward trajectory and potential source contribution function (PSCF) analysis in the light of atmospheric pollutants suggested that the potential source areas mainly involved the surrounding regions of Shijiazhuang, i.e. south of Hebei and north of Henan and Shanxi. The regional nature of the atmospheric pollution in the North China Plain revealed that there is an urgent need for making cross-boundary control policies in addition to local control measures given the high background level of pollutants.The TECA is an important practical exercise but it cannot be advocated for as the normalized control measures for atmospheric pollution in China. The direct cause of atmospheric pollution in China is the emission of pollutants exceeding the air environment's self-purification capacity, which is caused by an unreasonable and unhealthy pattern for economic development in China.

Recent high energy gamma-ray results from SAS-2

NASA Technical Reports Server (NTRS)

Thompson, D. J.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Bignami, G. F.; Ogelman, H. B.; Ozel, M. E.; Tumer, T.; Lamb, R. C.

1977-01-01

Recent developments in gamma-ray astronomy due to the results from SAS-2 have focused on two areas. First, the emission from the plane of the Galaxy is the dominant feature in the gamma-ray sky. The galactic latitude and longitude distributions are consistent with the concept that the high-energy radiation originates from cosmic rays interacting with interstellar matter, and the measurements support a galactic origin for cosmic rays. Second, searches of the SAS-2 data for emission from localized sources have shown three strong discrete gamma-ray sources: the Crab nebula and PSR 0531 + 21, the Vela supernova remnant and PSR 0833-45, and a source near galactic coordinates 193 deg longitude, +3 deg latitude, which does not appear to be associated with other known celestial objects. Evidence has also been found for pulsed gamma-ray emission from two other radio pulsars, PSR 1818-04 and PSR 1747-46. A localized source near longitudes 76-80 deg may be associated with the X-ray source Cyg X-3.

Comparing top-down and bottom-up estimates of methane emissions across multiple U.S. oil and gas basins provides insights into national O&G emissions, mitigation strategies, and research priorities

NASA Astrophysics Data System (ADS)

Lyon, D. R.; Alvarez, R.; Zavala Araiza, D.; Hamburg, S.

2017-12-01

We develop a county-level inventory of U.S. anthropogenic methane emissions by integrating multiple data sources including the Drillinginfo oil and gas (O&G) production database, Environmental Protection Agency (EPA) Greenhouse Gas Reporting Program, a previously published gridded EPA Greenhouse Gas Inventory (Maasakkers et al 2016), and recent measurements studies of O&G pneumatic devices, equipment leaks, abandoned wells, and midstream facilities. Our bottom-up estimates of total and O&G methane emissions are consistently lower than top-down, aerial mass balance estimates in ten O&G production areas. We evaluate several hypotheses for the top-down/bottom-up discrepancy including potential bias of the aerial mass balance method, temporal mismatch of top-down and bottom-up emission estimates, and source attribution errors. In most basins, the top-down/bottom-up gap cannot be explained fully without additional O&G emissions from sources not included in traditional inventories, such as super-emitters caused by malfunctions or abnormal process conditions. Top-down/bottom-up differences across multiple basins are analyzed to estimate the magnitude of these additional emissions and constrain total methane emissions from the U.S. O&G supply chain. We discuss the implications for mitigating O&G methane emissions and suggest research priorities for increasing the accuracy of future emission inventories.

40 CFR 63.6603 - What emission limitations and operating limitations must I meet if I own or operate an existing...

Code of Federal Regulations, 2011 CFR

2011-07-01

... operating limitations must I meet if I own or operate an existing stationary RICE located at an area source... operating limitations must I meet if I own or operate an existing stationary RICE located at an area source... procedures in § 63.6620 and Table 4 to this subpart. (a) If you own or operate an existing stationary RICE...

Accuracy of vertical radial plume mapping technique in measuring lagoon gas emission

USDA-ARS?s Scientific Manuscript database

Recently, the U.S. Environmental Protection Agency (USEPA) posted a ground-based optical remote sensing method on its website called OTM 10 for measuring fugitive gas emission flux from area sources such as closed landfills. The OTM 10 utilizes the vertical radial plume mapping (VRPM) technique to c...

Field determination of multipollutant, open area combustion source emission factors with a hexacopter unmanned aerial vehicle

EPA Science Inventory

An emission sensor/sampler system was coupled to a NASA hexacopter unmanned aerial system (UAS) to characterize gases and particles in the plume emitted from open burning of military ordnance. The UAS/sampler was tested at two field sites resulting in 33 flights at Radford, VA a...

76 FR 15308 - Completion of the Requirement To Promulgate Emission Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-21

... CONTACT: Mr. Nathan Topham, Sector Policies and Programs Division, Office of Air Quality Planning and... the aggregate area source emissions of each of the 30 urban hazardous air pollutants (HAP) are subject... list of the 30 urban HAP, please see National Air Toxics Program: The Integrate Urban Strategy, 64 FR...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...

40 CFR Table 2 of Subpart Bbbbbbb... - Initial Compliance Demonstration Methods With the Emission Reduction and PM Concentration...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Emission Standards for Hazardous Air Pollutants for Area Sources: Chemical Preparations Industry Other... less; or c. Provide engineering calculations, such as mass balance and flow rate calculations, that demonstrate that the control device is capable of reducing PM concentration from the chemical preparations...