scholarly journals Observations of Acyl Peroxy Nitrates During the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ)

2017 ◽  
Vol 122 (22) ◽  
pp. 12,416-12,432 ◽  
Author(s):  
Jake Zaragoza ◽  
Sara Callahan ◽  
Erin E. McDuffie ◽  
Jeffrey Kirkland ◽  
Patrick Brophy ◽  
...  
Keyword(s):  
Air Pollution ◽  
Front Range ◽  
Peroxy Nitrates

scholarly journals Evolution of NO<sub><i>x</i></sub> in the Denver Urban Plume during the Front Range Air Pollution and Photochemistry Experiment

2017 ◽  
Author(s):  
Carlena J. Ebben ◽  
Tamara L. Sparks ◽  
Paul J. Wooldridge ◽  
Teresa L. Campos ◽  
Christopher A. Cantrell ◽  
...  
Keyword(s):  
Air Pollution ◽  
Numerical Models ◽  
Near Field ◽  
Photochemical Oxidation ◽  
Front Range ◽  
City Center ◽  
Alkyl Nitrates ◽  
Effective Lifetime ◽  
Urban Plume ◽  
The City

Abstract. As NOx (NOx ≡ NO + NO2) is transported away from cities, it undergoes photochemical oxidation to peroxynitrates (RO2NO2, ΣPNs), alkyl nitrates (RONO2, ΣANs), and nitric acid (HNO3). These higher oxide species each have different lifetimes to permanent removal or conversion back to NOx, resulting in nitrogen oxide chemistry that evolves as plumes are transported away from cities. Here, observations from the Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) are used to describe the evolution of NOx and NOy (NOy ≡ NOx + ΣPNs + ΣANs + HNO3 + …) as the Denver urban plume flows outward from the city center. We evaluate the chemistry, dilution, and deposition rates in the plume to provide numerical constraints on the NOx and NOy,i lifetimes. We find that plume dilution with background air occurs with a lifetime of 3.5 hours. NOx concentrations decrease more rapidly with a lifetime to chemical loss and dilution of 2 hours in the near field of the city center. NOy has an effective lifetime of 3 hours and due to a combination of HNO3 deposition and dilution. The results provide a useful test of conceptual and numerical models of chemistry during the evolution of urban plumes.

scholarly journals Aerosol Optical Extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) 2014 Summertime Field Campaign, Colorado U.S.A.

2016 ◽  
Author(s):  
Justin H. Dingle ◽  
Kennedy Vu ◽  
Roya Bahreini ◽  
Eric C. Apel ◽  
Teresa L. Campos ◽  
...  
Keyword(s):  
Air Pollution ◽  
Light Extinction ◽  
Organic Nitrate ◽  
Front Range ◽  
Aerosol Composition ◽  
Optical Extinction ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Optical Extinction ◽  
Air Mass Types

Abstract. Summertime aerosol optical extinction (βext) was measured in the Colorado Front Range and Denver Metropolitan Area as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPÉ) campaign during July–August 2014. An Aerodyne Cavity Attenuated Phase Shift particle light extinction monitor (CAPS-PMex) was deployed to measure dry, βext of submicron aerosols at λ = 632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret βext behavior under various categories of air masses and sources. Extinction enhancement ratios relative to CO (Δβext/ΔCO) were significantly increased in highly aged air masses compared to fresh air masses by 50–60 %. The resulting increase in Δβext/ΔCO under highly aged air masses was accompanied by formation of secondary organic aerosols (SOA). In addition, the impacts of aerosol composition on βext in air masses under the influence of urban, natural oil and gas operations (O&amp;G), and agriculture and livestock operations were evaluated. Estimated non-refractory mass extinction efficiency (MEE) values for different air mass types ranged from 1.83–3.30 m2 g−1, with the minimum and maximum values observed in agriculture and urban + O&amp;G influenced air masses, respectively. The mass distribution for organic, nitrate, and sulfate aerosols presented distinct profiles in different air mass types. During Aug. 11–12, regional influence of a biomass burning event was observed, increasing the background βext by 10–15 Mm−1 and the estimated MEE and Δβext/ΔCO values in the Front Range.

Acyl Peroxy Nitrates Link Oil and Natural Gas Emissions to High Ozone Abundances in the Colorado Front Range During Summer 2015

2019 ◽  
Vol 124 (4) ◽  
pp. 2336-2350 ◽  
Author(s):  
Jakob Lindaas ◽  
Delphine K. Farmer ◽  
Ilana B. Pollack ◽  
Andrew Abeleira ◽  
Frank Flocke ◽  
...  
Keyword(s):  
Natural Gas ◽  
Colorado Front Range ◽  
Front Range ◽  
Gas Emissions ◽  
Peroxy Nitrates ◽  
Oil And Natural Gas ◽  
Natural Gas Emissions

scholarly journals Air Quality in the Northern Colorado Front Range Metro Area: The Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ)

2020 ◽  
Vol 125 (2) ◽  
Author(s):  
Frank Flocke ◽  
Gabriele Pfister ◽  
James H. Crawford ◽  
Kenneth E. Pickering ◽  
Gordon Pierce ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Colorado Front Range ◽  
Front Range ◽  
Metro Area ◽  
Northern Colorado

scholarly journals Effect of Air Pollution on Precipitation along the Front Range of the Rocky Mountains

2006 ◽  
Vol 45 (1) ◽  
pp. 236-245 ◽  
Author(s):  
Israel L. Jirak ◽  
William R. Cotton
Keyword(s):  
Air Pollution ◽  
Rocky Mountains ◽  
Urban Areas ◽  
Cloud Droplet ◽  
Front Range ◽  
Past Half Century ◽  
Orographic Clouds ◽  
Pollution Emissions ◽  
Urban Sites ◽  
Precipitation Trends

Abstract Air pollution generated in industrial and urban areas can act to suppress precipitation by creating a narrow cloud droplet spectrum, which inhibits the collision and coalescence process. In fact, precipitation ratios of elevated sites to upwind coastal urban areas have decreased during the twentieth century for locations in California and Israel while pollution emissions have increased. Precipitation suppression by pollution should also be evident in other areas of the world where shallow, orographic clouds produce precipitation. This study investigates the precipitation trends for sites along the Front Range of the Rocky Mountains to determine the effect of air pollution on precipitation in this region. The examination of precipitation trends reveals that the ratio of upslope precipitation for elevated sites west of Denver and Colorado Springs, Colorado, to upwind urban sites has decreased by approximately 30% over the past half-century. Similar precipitation trends were not found for more pristine sites in the region, providing evidence of precipitation suppression by air pollution.

the inadvertent modification of the atmosphere by air pollution

1969 ◽  
Vol 50 (4) ◽  
pp. 199-207 ◽  
Author(s):  
Vincent J. Schaefer
Keyword(s):  
New York ◽  
Air Pollution ◽  
Los Angeles ◽  
San Francisco ◽  
Kansas City ◽  
The United States ◽  
Front Range ◽  
Noticeable Increase ◽  
The Past ◽  
Dense Concentration

There has been a very noticeable increase in air pollution during the past ten years over and downwind of the several large metropolitan areas of the United States such as the Northwest—Vancouver-Seattle-Tacoma-Portland; the West Coast from San Francisco-Sacramento-Fresno-Los Angeles; the Front Range of the Rockies from Boulder-Denver-Colorado Springs-Pueblo; the Midwest—Omaha-Kansas City-St. Louis-Memphis; the Great Lakes area of Chicago-Detroit-Cleveland-Buffalo; and the Northeast—Washington-Philadelphia-New York-Boston. The worst accumulation of particulate matter occurs at the top of the inversion which commonly intensifies at night at levels ranging from 1000 to 4000 ft or so above the ground. This dense concentration of air-suspended particles is most apparent to air travelers. Thus, it has not as yet disturbed the general public except during periods of stagnant weather systems when the concentration of heavily polluted air extends downward and engulfs them on the highways, at their homes and in their working areas.

scholarly journals Aerosol optical extinction during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) 2014 summertime field campaign, Colorado, USA

2016 ◽  
Vol 16 (17) ◽  
pp. 11207-11217 ◽  
Author(s):  
Justin H. Dingle ◽  
Kennedy Vu ◽  
Roya Bahreini ◽  
Eric C. Apel ◽  
Teresa L. Campos ◽  
...  
Keyword(s):  
Air Pollution ◽  
Light Extinction ◽  
Organic Nitrate ◽  
Front Range ◽  
Aerosol Composition ◽  
Optical Extinction ◽  
Air Mass ◽  
Air Masses ◽  
Aerosol Optical Extinction ◽  
Air Mass Types

Abstract. Summertime aerosol optical extinction (βext) was measured in the Colorado Front Range and Denver metropolitan area as part of the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) campaign during July–August 2014. An Aerodyne cavity attenuated phase shift particle light extinction monitor (CAPS-PMex) was deployed to measure βext (at average relative humidity of 20 ± 7 %) of submicron aerosols at λ = 632 nm at 1 Hz. Data from a suite of gas-phase instrumentation were used to interpret βext behavior in various categories of air masses and sources. Extinction enhancement ratios relative to CO (Δβext ∕ ΔCO) were higher in aged urban air masses compared to fresh air masses by  ∼  50 %. The resulting increase in Δβext ∕ ΔCO for highly aged air masses was accompanied by formation of secondary organic aerosols (SOAs). In addition, the impacts of aerosol composition on βext in air masses under the influence of urban, natural oil and gas operations (O&amp;G), and agriculture and livestock operations were evaluated. Estimated non-refractory mass extinction efficiency (MEE) values for different air mass types ranged from 1.51 to 2.27 m2 g−1, with the minimum and maximum values observed in urban and agriculture-influenced air masses, respectively. The mass distribution for organic, nitrate, and sulfate aerosols presented distinct profiles in different air mass types. During 11–12 August, regional influence of a biomass burning event was observed, increasing the background βext and estimated MEE values in the Front Range.

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