scholarly journals Long-term atmospheric emissions for the Coal Oil Point natural marine hydrocarbon seep field, offshore California

2021 ◽  
Vol 21 (23) ◽  
pp. 17607-17629
Author(s):  
Ira Leifer ◽  
Christopher Melton ◽  
Donald R. Blake
Keyword(s):  
Air Quality ◽  
Grid Cell ◽  
Total Carbon ◽  
Atmospheric Emissions ◽  
Model Inversion ◽  
Inversion Model ◽  
In Situ Data ◽  
Novel Approach ◽  
Gaussian Plume ◽  
Plume Composition

Abstract. In this study, we present a novel approach for assessing nearshore seepage atmospheric emissions through modeling of air quality station data, specifically a Gaussian plume inversion model. A total of 3 decades of air quality station meteorology and total hydrocarbon concentration, THC, data were analyzed to study emissions from the Coal Oil Point marine seep field offshore California. THC in the seep field directions was significantly elevated and Gaussian with respect to wind direction, θ. An inversion model of the seep field, θ-resolved anomaly, THC′(θ)-derived atmospheric emissions is given. The model inversion is for the far field, which was satisfied by gridding the sonar seepage and treating each grid cell as a separate Gaussian plume. This assumption was validated by offshore in situ data that showed major seep area plumes were Gaussian. Plume total carbon, TC (TC = THC + carbon dioxide, CO2, + carbon monoxide), 18 % was CO2 and 82 % was THC; 85 % of THC was CH4. These compositions were similar to the seabed composition, demonstrating efficient vertical plume transport of dissolved seep gases. Air samples also measured atmospheric alkane plume composition. The inversion model used observed winds and derived the 3-decade-average (1990–2021) field-wide atmospheric emissions of 83 400 ± 12 000 m3 THC d−1 (27 Gg THC yr−1 based on 19.6 g mol−1 for THC). Based on a 50 : 50 air-to-seawater partitioning, this implies seabed emissions of 167 000 m3 THC d−1. Based on atmospheric plume composition, C1–C6 alkane emissions were 19, 1.3, 2.5, 2.2, 1.1, and 0.15 Gg yr−1, respectively. The spatially averaged CH4 emissions over the ∼ 6.3 km2 of 25 × 25 m2 bins with sonar values above noise were 5.7 µM m−2 s−1. The approach can be extended to derive emissions from other dispersed sources such as landfills, industrial sites, or terrestrial seepage if source locations are constrained spatially.

scholarly journals Long-Term Atmospheric Emissions for the Coal Oil Point Natural Marine Hydrocarbon Seep Field, Offshore California

2021 ◽  
Author(s):  
Ira Leifer ◽  
Christopher Melton ◽  
Donald R. Blake
Keyword(s):  
Air Quality ◽  
Grid Cell ◽  
Atmospheric Emissions ◽  
Model Inversion ◽  
Inversion Model ◽  
Industrial Sites ◽  
Novel Approach ◽  
Gaussian Plume ◽  
Carbon Dioxide Co2 ◽  
Plume Composition

Abstract. In this study, we present a novel approach for assessing nearshore seepage atmospheric emissions through modeling of air quality station data, specifically, a Gaussian plume inversion model. Three decades of air quality station meteorology and total hydrocarbon concentration, THC, data were analysed to study emissions from the Coal Oil Point marine seep field offshore California. THC in the seep field directions was significantly elevated and Gaussian with respect to wind direction, θ. An inversion model of the seep field anomaly, THC’(θ), derived atmospheric emissions. The model inversion is for the far field, which was satisfied by gridding the sonar seepage and treating each grid cell as a separate Gaussian plume. This assumption was validated by offshore in situ offshore data that showed major seep area plumes were Gaussian. Plume air sample THC was 85 % methane, CH4, and 20 % carbon dioxide, CO2, similar to seabed composition, demonstrating efficient vertical plume transport of dissolved seep gases. Air samples also measured atmospheric alkane plume composition. The inversion model used observed winds and derived the three-decade-average (1990–2021) field-wide atmospheric emissions of 83,500 ± 12,000 m3 THC day−1. Based on a 50:50 air to seawater partitioning, this implies seabed emissions of 167,000 m3 THC dy−1. Based on atmospheric plume composition, C1-C6 alkane emissions were 19, 1.3, 2.5, 2.2, 1.1, and 0.15 Gg yr−1, respectively. The approach can be extended to derive emissions from other dispersed sources such as landfills, industrial sites, or terrestrial seepage if source locations are constrained spatially.

scholarly journals Reviewing the Crop Residual Burning and Aerosol Variations during the COVID-19 Pandemic Hit Year 2020 over North India

Pollutants ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 127-140
Author(s):  
Manoj Hari ◽  
Rajesh Kumar Sahu ◽  
Bhishma Tyagi ◽  
Ravikant Kaushik
Keyword(s):  
Air Quality ◽  
Agricultural Waste ◽  
North India ◽  
National Capital Region ◽  
Industrial Emissions ◽  
Indian States ◽  
Back Trajectories ◽  
In Situ Data ◽  
National Capital ◽  
Waste Burning

The north Indian states of Haryana and Punjab are believed to be the key sources of air pollution in the National Capital Region due to massive agricultural waste burning in crop harvesting seasons. However, with the pandemic COVID-19 hitting the country, the usual practices were disrupted. COVID-19 preventive lockdown led to restricted vehicular and industrial emissions and caused the labours to leave the agricultural business in Haryana and Punjab. With the changed scenario of 2020, the present study investigates the variations in air quality over the Haryana and Punjab, and their relative impact on the air quality of Delhi. The work attempts to understand the change in agricultural waste burning during 2020 and its implication on the local air quality over both the states and the transported pollution on the national capital Delhi. The study utilises in-situ data for the year 2019–2020 with satellite observations of MODIS aqua/terra for fire counts, aerosol optical depth (AOD) and back-trajectories run by the hybrid single-particle Lagrangian integrated trajectory model (HYSPLIT).

The Influence of Shale Rock Fracturing Equipment Operation on Atmospheric Air Quality

2014 ◽  
Vol 59 (4) ◽  
pp. 897-912 ◽  
Author(s):  
Marek Bogacki ◽  
Jan Macuda
Keyword(s):  
Air Quality ◽  
Nitrogen Oxides ◽  
Hydraulic Fracturing ◽  
High Power ◽  
Total Power ◽  
Atmospheric Emissions ◽  
Technological Systems ◽  
Rock Fracturing ◽  
Emission Standards ◽  
Benzene Toluene

Abstract The hydraulic fracturing jobs performed on shale rocks are connected with atmospheric emissions of dusts and exhaust gases from high-power motors supplying pump aggregates used for fracturing operations and from other technological devices. The total power of motors driving technological systems depends on the specific character of deposit and well and may range between a dozen to tens of thousands kW. An exemplary set of technological systems used for frac jobs is presented in figure 1. The following substances are emitted to the atmosphere during engine operation, e.g. nitrogen oxides (NOx), sulfur dioxide (SO2), carbon oxide (CO), dust PM10, ammonia, benzo(a)pyrene (B(a)P), benzene, toluene, xylene, formaldehyde, acetaldehyde, acrolein. As a consequence admissible concentrations of these substances in air can be exceeded. The influence of dust and gaseous emissions accompanying shale rock fracturing jobs is addressed in this paper. Model analyses were performed. An exemplary model of a process used for simulating propagation of atmospheric emissions in a specified calculation area (1,150 m × 1,150 m) were based on the analysis of hydraulic fracturing jobs performed in wells in Poland and abroad. For making calculations more actual, the model was located in the Gdańsk area and was ascribed its typical meteorological and orographic parameters. In the center of this area a rig site 150 m x 150 m was distinguished. The emission field was generated by 12 high-power engines supplying pump aggregates, 1680 kW each. The time of work of particular engines was established for 52 hrs (13 frac jobs, each lasting 4 hrs). It was assumed that all engines will operate simultaneously and using 100% of their power. Attention was paid to the correct modelling of the real emission field. Technical parameters of motors and the applied fuels were characterized. Emission indices were worked out by, e.g. U.S. Environmental Protection Agency or European Environment Agency. The calculations of air pollutions from analyzed motors were performed with a mathematical modelling method using Gaussian plum. The results of calculations could be used for evaluating spatial distribution of maximum 1 hour concentrations (S1), incidence of exceeding admissible 1 hour concentration values (P(D1)), percentile 99.8 or 99.726 from 1 hour concentrations and average concentrations (Sa) for selected most important for the air quality contaminants, i.e. NOx (as NO2), SO2, CO, PM10, benzo(a)pyrene, benzene, toluene, xylene, formaldehyde, acetaldehyde and acrolein. The results of calculated air concentrations of selected substances on the rig border are listed in table 9, whereas spatial distributions of NOx and PM10 concentrations in figures 3 to 8. The analysis of the obtained results did not reveal cases of exceeding Polish emission standards. However, nitrogen oxide (NOx) or dust PM10 can be expected to exceed these values, e.g. in a situation when the total power installed in motors driving technological systems in the course of hydraulic fracking will be higher than assumed in the analyses. The results of calculations show to a significant impact of nitrogen oxides (NOx) and dust PM10 emissions on air quality. The risk that emission standards are exceeded beyond the rig area is conditioned both by technological factors (total power of operating motors, parameters of combusted fuel, reduced emission technologies applied to engines, duration of frac jobs, etc.) and a number of external factors, e.g. meteorological and orographic factors or high level of emitted substances in air within the rig area.

scholarly journals A plume-in-grid approach to characterize air quality impacts of aircraft emissions at the Hartsfield–Jackson Atlanta International Airport

2013 ◽  
Vol 13 (18) ◽  
pp. 9285-9302 ◽  
Author(s):  
J. Rissman ◽  
S. Arunachalam ◽  
M. Woody ◽  
J. J. West ◽  
T. BenDor ◽  
...  
Keyword(s):  
Air Quality ◽  
Grid Cell ◽  
Ground Level ◽  
Grid Cells ◽  
Aircraft Emissions ◽  
International Airport ◽  
Grid Approach ◽  
Subgrid Scales ◽  
Order Of Magnitude ◽  
The One

Abstract. This study examined the impacts of aircraft emissions during the landing and takeoff cycle on PM2.5 concentrations during the months of June and July 2002 at the Hartsfield–Jackson Atlanta International Airport. Primary and secondary pollutants were modeled using the Advanced Modeling System for Transport, Emissions, Reactions, and Deposition of Atmospheric Matter (AMSTERDAM). AMSTERDAM is a modified version of the Community Multiscale Air Quality (CMAQ) model that incorporates a plume-in-grid process to simulate emissions sources of interest at a finer scale than can be achieved using CMAQ's model grid. Three fundamental issues were investigated: the effects of aircraft on PM2.5 concentrations throughout northern Georgia, the differences resulting from use of AMSTERDAM's plume-in-grid process rather than a traditional CMAQ simulation, and the concentrations observed in aircraft plumes at subgrid scales. Comparison of model results with an air quality monitor located in the vicinity of the airport found that normalized mean bias ranges from −77.5% to 6.2% and normalized mean error ranges from 40.4% to 77.5%, varying by species. Aircraft influence average PM2.5 concentrations by up to 0.232 μg m−3 near the airport and by 0.001–0.007 μg m−3 throughout the Atlanta metro area. The plume-in-grid process increases concentrations of secondary PM pollutants by 0.005–0.020 μg m−3 (compared to the traditional grid-based treatment) but reduces the concentration of non-reactive primary PM pollutants by up to 0.010 μg m−3, with changes concentrated near the airport. Examination of subgrid-scale results indicates that median aircraft contribution to grid cells is higher than median puff concentration in the airport's grid cell and outside of a 20 km × 20 km square area centered on the airport, while in a 12 km × 12 km square ring centered on the airport, puffs have median concentrations over an order of magnitude higher than aircraft contribution to the grid cells. Maximum puff impacts are seen within the 12 km × 12 km ring, not in the airport's own grid cell, while maximum grid cell impacts occur within the airport's grid cell. Twenty-one (21)% of all aircraft-related puffs from the Atlanta airport have at least 0.1 μg m−3 PM2.5 concentrations. Near the airport, median daily puff concentrations vary between 0.017 and 0.134 μg m−3 (0.05 and 0.35 μg m−3 at ground level), while maximum daily puff concentrations vary between 6.1 and 42.1 μg m−3 (7.5 and 42.1 μg m−3 at ground level) during the 2-month period. In contrast, median daily aircraft contribution to grid concentrations varies between 0.015 and 0.091 μg m−3 (0.09 and 0.40 μg m−3 at ground level), while the maximum varies between 0.75 and 2.55 μg m−3 (0.75 and 2.0 μg m−3 at ground level). Future researchers may consider using a plume-in-grid process, such as the one used here, to understand the impacts of aircraft emissions at other airports, for proposed future airports, for airport expansion projects under various future scenarios, and for other national-scale studies specifically when the maximum impacts at fine scales are of interest.

scholarly journals A Decadal Synthesis of Atmospheric Emissions, Ambient Air Quality, and Deposition in the Oil Sands Region

2021 ◽  
Author(s):  
Erin C. Horb ◽  
Gregory R. Wentworth ◽  
Paul A. Makar ◽  
John Liggio ◽  
Katherine Hayden ◽  
...  
Keyword(s):  
Air Quality ◽  
Oil Sands ◽  
Ambient Air ◽  
Atmospheric Emissions ◽  
Ambient Air Quality

scholarly journals An integrated approach for the evaluation of technological hazard impacts on air quality: the case of the Val d'Agri oil/gas plant

2014 ◽  
Vol 2 (4) ◽  
pp. 2345-2376
Author(s):  
M. Calvello ◽  
F. Esposito ◽  
S. Trippetta
Keyword(s):  
Air Quality ◽  
Treatment Plant ◽  
Monitoring Network ◽  
Integrated Approach ◽  
Preliminary Evaluation ◽  
Air Quality Measurements ◽  
Novel Approach ◽  
Starting Point ◽  
Pre Treatment ◽  
Oil Gas

Abstract. The Val d'Agri area (southern Italy) hosts the biggest on-shore European reservoir and the largest oil/gas pre-treatment plant, named Centro Olio Val d'Agri (COVA), located in a rural/anthropized context. Several hazards are associated to this plant. These are mainly represented by possible impacts of the COVA atmospheric emissions on the local air quality and human health. This work uses a novel approach based on the integration of air quality measurements from the regional monitoring network, additional experimental measurements (i.e., sub-micrometric particulate matter – PM1 and Black Carbon – BC) and advanced statistical analyses to provide a preliminary evaluation of the Val d'Agri air quality state and give some indications of specific areas potentially affected by COVA hazards. Results show that the COVA plant emissions exert an impact especially on the air quality of the area closest to it. In this area several pollutants specifically related to the COVA combustion processes (i.e., nitrogen oxides, benzene and toluene) show the highest concentration values and significant correlations. The proposed approach represents a first step in the assessment of the risks associated to oil/gas exploration and pre-treatment activities and a starting point for the development of effective and exportable air quality monitoring strategies.

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