A Comprehensive Integration and Synthesis of Methane Emissions from Canada's Oil and Gas Value Chain.

Methane emissions from the global oil and gas value chain are a major contributor to climate change, and their mitigation could avoid 0.1 °C of warming by 2050. Here, we synthesize nearly a decade of research encompassing thousands of multiscale methane measurements along the oil and gas value chain (production to end use) to better constrain estimates of methane emissions from Canada's energy sector and to identify research gaps contributing to uncertainty in current estimates.

Direct measurements of methane emissions from key facilities in Alberta's oil and gas supply chain.

The Canadian government aims to achieve a 40-45 % reduction of oil and gas (O&G) methane (CH) emissions by 2025, and 75 % by 2030, although recent studies consistently show that Canada's federal inventory underestimates emissions by a factor of 1.4 to 2.0.

Constraining natural gas pipeline emissions in San Juan Basin using mobile sampling.

Quantifying methane (CH) leaks of pipeline systems is critical to ensure accurate emission factors in regional and global atmospheric models. The previous emission factors in the United States Environmental Protection Agency (EPA) Greenhouse Gas Inventory (GHGI) are from 1996 and do not reflect the modern gathering pipeline system. Additional data from different basins across the United States are urgently needed to improve the emission factors.

Quantifying source contributions of volatile organic compounds under hydraulic fracking moratorium.

Volatile organic compounds (VOCs) are precursors for ozone (O) and secondary particulate matter, which contribute to asthma and cardiovascular diseases. With the technology development of hydraulic fracking, the United States experienced a shale gas boom in the last decade while the public raised concerns about the potential health impacts of co-emitted VOCs and other airborne pollutants. National Energy Technology Laboratory conducted stationary trailer-based ambient monitoring to study the sources of VOCs in Maryland, where the state enacted a moratorium on unconventional natural gas extraction.

Moving beyond Fine Particle Mass: High-Spatial Resolution Exposure to Source-Resolved Atmospheric Particle Number and Chemical Mixing State.

Background: Most epidemiological studies address health effects of atmospheric particulate matter (PM) using mass-based measurements as exposure surrogates. However, this approach ignores many critical physiochemical properties of individual atmospheric particles. These properties control the deposition of particles in the human lung and likely their toxicity; in addition, they likely have larger spatial variability than PM mass.

Land-Use Regression Modeling of Source-Resolved Fine Particulate Matter Components from Mobile Sampling.

This study presents land-use regression (LUR) models for submicron particulate matter (PM) components from an urban area. Models are presented for mass concentrations of inorganic species (SO, NO, NH), organic aerosol (OA) factors, and total PM. OA is source-apportioned using positive matrix factorization (PMF) of data collected from aerosol mass spectrometry deployed on a mobile laboratory.

Urban Ultrafine Particle Exposure Assessment with Land-Use Regression: Influence of Sampling Strategy.

Sampling strategies in the collection of ultrafine particle (UFP) data to develop land-use regression (LUR) models can strongly influence the resulting exposure estimates. Here, we systematically examine how much sampling is needed to develop robust and stable UFP LUR models. To address this question, we collected 3-6 weeks of continuous measurements of UFP concentrations at 32 sites in Pittsburgh, Pennsylvania covering a wide range of urban land-use attributes.

Quantifying Urban Spatial Variations of Anthropogenic VOC Concentrations and Source Contributions with a Mobile Sampling Platform.

Volatile organic compounds (VOCs) are important atmospheric constituents because they contribute to formation of ozone and secondary aerosols, and because some VOCs are toxic air pollutants. We measured concentrations of a suite of anthropogenic VOCs during summer and winter at 70 locations representing different microenvironments around Pittsburgh, PA. The sampling sites were classified both by land use (e.

Intracity Variability of Particulate Matter Exposure Is Driven by Carbonaceous Sources and Correlated with Land-Use Variables.

Localized primary emissions of carbonaceous aerosol are the major drivers of intracity variability of submicron particulate matter (PM) concentrations. We investigated spatial variations in PM composition with mobile sampling in Pittsburgh, Pennsylvania, United States and performed source-apportionment analysis to attribute primary organic aerosol (OA) to traffic (HOA) and cooking OA (COA). In high-source-impact locations, the PM concentration is, on average, 2 μg m (40%) higher than urban background locations.

Restaurant Impacts on Outdoor Air Quality: Elevated Organic Aerosol Mass from Restaurant Cooking with Neighborhood-Scale Plume Extents.

Organic aerosol (OA) is a major component of fine particulate matter (PM) in urban environments. We performed in-motion ambient sampling from a mobile platform with an aerosol mass spectrometer (AMS) to investigate the spatial variability and sources of OA concentrations in Pittsburgh, Pennsylvania, a midsize, largely postindustrial American city. To characterize the relative importance of cooking and traffic sources, we sampled in some of the most populated areas (∼18 km) in and around Pittsburgh during afternoon rush hour and evening mealtime, including congested highways, major local roads, areas with high densities of restaurants, and urban background locations.

Spatial Variability of Sources and Mixing State of Atmospheric Particles in a Metropolitan Area.

Characterizing intracity variations of atmospheric particulate matter has mostly relied on fixed-site monitoring and quantifying variability in terms of different bulk aerosol species. In this study, we performed ground-based mobile measurements using a single-particle mass spectrometer to study spatial patterns of source-specific particles and the evolution of particle mixing state in 21 areas in the metropolitan area of Pittsburgh, PA. We selected sampling areas based on traffic density and restaurant density with each area ranging from 0.

Urban Organic Aerosol Exposure: Spatial Variations in Composition and Source Impacts.

We conducted a mobile sampling campaign in a historically industrialized terrain (Pittsburgh, PA) targeting spatial heterogeneity of organic aerosol. Thirty-six sampling sites were chosen based on stratification of traffic, industrial source density, and elevation. We collected organic carbon (OC) on quartz filters, quantified different OC components with thermal-optical analysis, and grouped them based on volatility in decreasing order (OC1, OC2, OC3, OC4, and pyrolyzed carbon (PC)).