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Non-methane volatile organic compounds (NMVOCs) generate ozone (O 3) when they are oxidised in the presence of oxides of nitrogen, modulate the oxidative capacity of the atmosphere and can lead to the formation of aerosol. Here, we assess the capability of a chemical transport model (GEOS-Chem) to simulate NMVOC concentrations by comparing ethane, propane and higher-alkane observations in remote regions from the NOAA flask Network and the World Meteorological Organization's Global Atmosphere Watch (GAW) network. Using the Community Emissions Data System (CEDS) inventory, we find a significant underestimate in the simulated concentration of both ethane (35 %) and propane (64 %), consistent with previous studies. We run a new simulation in which the total mass of anthropogenic NMVOC emitted in a grid box is the same as that used in CEDS but with the NMVOC speciation derived from regional inventories. For US emissions, we use the National Emissions Inventory (NEI); for Europe, we use the UK National Atmospheric Emissions Inventory (NAEI); and for China, we use the Multi-resolution Emission Inventory model for Climate and air pollution research (MEIC). These changes lead to a large increase in the modelled concentrations of ethane, improving the mean model bias from - 35 % to - 4 %. Simulated propane also improves (from - 64 % to - 48 % mean model bias), but there remains a substantial model underestimate. There were relatively minor changes to other NMVOCs. The low bias in simulated global ethane concentration is essentially removed, resolving one long-term issue in global simulations. Propane concentrations are improved but remain significantly underestimated, suggesting the potential for a missing global propane source. The change in the NMVOC emission speciation results in only minor changes in tropospheric O 3 and OH concentrations. [ABSTRACT FROM AUTHOR]

Anthropogenic non-methane volatile organic compounds (VOCs) in the United Kingdom have been substantially reduced since 1990, which is, in part, attributed to controls on evaporative and vehicle tailpipe emissions. Over time, other sources with a different speciation (for example, alcohols from solvent use and industry processes) have grown in both relative importance and, in some cases, in absolute terms. The impact of this change in speciation and the resulting photochemical reactivities of VOCs are evaluated using a photochemical box model constrained by observational data during a summertime ozone event (Birmingham, UK) and apportionment of sources based on the UK National Atmospheric Emission Inventory (NAEI) data over the period 1990–2019. Despite road transport sources representing only 3.3 % of UK VOC emissions in 2019, road transport continued being the sector with the largest influence on the local O 3 production rate (P(O 3)). Under case study conditions, the 96 % reduction in road transport VOC emissions that has been achieved between 1990 and 2019 has likely reduced daytime P(O 3) by ∼ 1.67 ppbv h -1. Further abatement of fuel fugitive emissions was modeled to have had less impact on P(O 3) reduction than abatement of VOCs from industrial processes and solvent use. The long-term trend of increased emissions of ethanol and methanol has somewhat weakened the benefits of reducing road transport emissions, increasing P(O 3) by ∼ 0.19 ppbv h -1 in the case study. Abatement of VOC emissions from multiple sources has been a notable technical and policy success in the UK, but some future benefits (from an ozone perspective) of the phase-out of internal combustion engine passenger cars may be offset if domestic and commercial solvent use of VOCs continue to increase. [ABSTRACT FROM AUTHOR]

The partnership between Tohono O'odham Community College (TOCC) and the Southwest Environmental Health Sciences Center (SWEHSC) at the University of Arizona (UA) has relied on principles that have produced a long-term relationship and full participation among the partners. Active listening, travelling to the community, longevity, understanding ways of life within the partner's community, the intent to serve the community, and agreeing not to publish without the tribe's permission are critical to the success of the partnership (London, Haapanen, Backus, Mack, Lindsey, & Andrade, 2020). Relying on these principles and shared leadership, the partners created the program "A Student's Journey (ASJ)" to reduce barriers in transitioning from a community college to a four-year university and to create career pathways for Native American students. Both partnering organizations seek to address the problem of low bachelor's degree attainment among tribal students (NCES, 2017; PNPI, 2018). Additional shared concerns include barriers to Native student persistence and resilience, two concepts at the forefront of low bachelor's degree attainment. Organized through an environmental health and social justice lens, ASJ allows students to investigate environmental impacts on human health and serves as a vehicle for social justice discussions while establishing a foundation for Native nation-building. More specifically, ASJ operates in an asset-based model that recognizes cultural knowledge and Native ways of knowing as a strength of the ASJ participants rather than as a deficit. ASJ utilizes this asset-based model to promote a successful transfer pathway to four-year colleges and universities for TOCC students.

Non-Methane Volatile Organic Compounds (NMVOCs) generate ozone (O3) when they are oxidized in the presence of oxides of nitrogen, modulate the oxidative capacity of the atmosphere and can lead to the formation of aerosol. Here, we assess the capability of a chemical transport model (GEOS-Chem) to simulate NMVOC concentrations by comparing ethane, propane and higher alkane observations in remote regions from the NOAA Flask Network and the World Meteorological Organization's Global Atmosphere Watch (GAW) network. Using the Community Emissions Data System (CEDS) inventory we find a significant underestimate in the simulated concentration of both ethane (35 %) and propane (64 %), consistent with previous studies. We run a new simulation where the total mass of anthropogenic NMVOC emitted in a grid box is the same as that used in CEDS, but with the NMVOC speciation derived from regional inventories. For US emissions we use the National Emissions Inventory (NEI), for Europe we use the UK National Atmospheric Emissions Inventory (NAEI), and for China, the Multi-resolution Emission Inventory for China (MEIC). These changes lead to a large increase in the modelled concentrations of ethane, improving the mean model bias from -35 % to -3.8 %. Simulated propane also improves (from -64 % to -48.0 % mean model bias), but there remains a substantial model underestimate. There were relatively minor changes to other NMVOCs. The low bias in simulated global ethane concentration is essentially removed, resolving one long-term issue in global simulations. Propane concentrations are improved but remain significantly underestimated, suggesting the potential for a missing global propane source. The change in the NMVOC emission speciation results in only minor changes in tropospheric O3 and OH concentrations. [ABSTRACT FROM AUTHOR]

Non-Methane Volatile Organic Compounds (NMVOCs) generate ozone (O3) when they are oxidized in the presence of oxides of nitrogen, modulate the oxidative capacity of the atmosphere and can lead to the formation of aerosol. Here, we assess the capability of a chemical transport model (GEOS-Chem) to simulate NMVOC concentrations by comparing ethane, propane and higher alkane observations in remote regions from the NOAA Flask Network and the World Meteorological Organization's 5 Global Atmosphere Watch (GAW) network. Using the Community Emissions Data System (CEDS) inventory we find a significant underestimate in the simulated concentration of both ethane (35%) and propane (64%), consistent with previous studies. We run a new simulation where the total mass of anthropogenic NMVOC emitted in a grid box is the same as that used in CEDS, but with the NMVOC speciation derived from regional inventories. For US emissions we use the National Emissions Inventory (NEI), for Europe we use the UK National Atmospheric Emissions Inventory (NAEI), and for China, the Multi-resolution Emission Inventory for China (MEIC). These changes lead to a large increase in the modelled concentrations of ethane, improving the mean model bias from -35% to -3.8%. Simulated propane also improves (from -64% to -48.0% mean model bias), but there remains a substantial model underestimate. There were relatively minor changes to other NMVOCs. The low bias in simulated global ethane concentration is essentially removed, resolving one long-term issue in global simulations. Propane concentrations are improved but remain significantly underestimated, suggesting the potential for a missing global propane source. The change in the NMVOC emission speciation results in only minor changes in tropospheric O3 and OH concentrations. [ABSTRACT FROM AUTHOR]

Anthropogenic non-methane volatile organic compounds (VOCs) in the United Kingdom have been substantial reduced since 1990, partly attributed to controls on evaporative and vehicle tailpipe emissions. Over time other sources with a different speciation, for example alcohols from solvent use and industry processes, have grown in both relative importance and in some cases in absolute terms. The impact of this change in speciation and the resulting photochemical reactivities of VOCs are evaluated using a photochemical box model constrained by observational data during a summertime ozone event (Birmingham, UK), and speciation and apportionment of sources based on the UK national atmospheric emission inventory (NAEI) data over the period 1990–2019. Despite road transport sources representing only 3.3 % of UK VOC emissions in 2019, it continued as the sector with the largest influence on local O3 production rate (P(O3)). Under case study conditions, the 96 % reduction in road transport VOC emissions that has been achieved between 1990–2019 has likely reduced daytime P(O3) by ~1.67 ppbv h-1. Further abatement of fuel fugitive emissions was modeled to have had less impact on P(O3) reduction than abatement of VOCs from industrial processes and solvent emissions. The long-term trend of increased emissions of ethanol and methanol have somewhat weakened the benefits of reducing road transport emissions, increasing P(O3) by ~0.19 ppbv h-1 in the case study. Abatement of VOC emissions from multiple sources has been a notable technical and policy success in the UK, but some future benefits (from an ozone perspective) of the phase out of internal combustion engine passenger cars may be offset if domestic and commercial solvent emissions of VOCs were to continue to increase. [ABSTRACT FROM AUTHOR]

Anthropogenic non-methane volatile organic compounds (VOCs) in the United Kingdom have been substantial reduced since 1990, partly attributed to controls on evaporative and vehicle tailpipe emissions. Over time other sources with a different speciation, for example alcohols from solvent use and industry processes, have grown in both relative importance and in some cases in absolute terms. The impact of this change in speciation and the resulting photochemical reactivities of VOCs are evaluated using a photochemical box model constrained by observational data during a summertime ozone event (Birmingham, UK), and speciation and apportionment of sources based on the UK national atmospheric emission inventory (NAEI) data over the period 1990-2019. Despite road transport sources representing only 3.3% of UK VOC emissions in 2019, it continued as the sector with the largest influence on local O3 production rate (P(O3)). Under case study conditions, the 96% reduction in road transport VOC emissions that has been achieved between 1990 - 2019 has likely reduced daytime P(O3) by ~1.67 ppbv h-1. Further abatement of fuel fugitive emissions was modeled to have had less impact on P(O3) reduction than abatement of VOCs from industrial processes and solvent emissions. The long-term trend of increased emissions of ethanol and methanol have somewhat weakened the benefits of reducing road transport emissions, increasing P(O3) by ~0.19 ppbv h-1 in the case study. Abatement of VOC emissions from multiple sources has been a notable technical and policy success in the UK, but some future benefits (from an ozone perspective) of the phase out of internal combustion engine passenger cars may be offset if domestic and commercial solvent emissions of VOCs were to continue to increase. [ABSTRACT FROM AUTHOR]