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  1. Article ; Online: Taehwa Research Forest

    J. T. Sullivan / T. J. McGee / R. M. Stauffer / A. M. Thompson / A. Weinheimer / C. Knote / S. Janz / A. Wisthaler / R. Long / J. Szykman / J. Park / Y. Lee / S. Kim / D. Jeong / D. Sanchez / L. Twigg / G. Sumnicht / T. Knepp / J. R. Schroeder

    Atmospheric Chemistry and Physics, Vol 19, Pp 5051-

    a receptor site for severe domestic pollution events in Korea during 2016

    2019  Volume 5067

    Abstract: During the May–June 2016 International Cooperative Air Quality Field Study in Korea (KORUS-AQ), light synoptic meteorological forcing facilitated Seoul metropolitan pollution outflow to reach the remote Taehwa Research Forest (TRF) site and cause ... ...

    Abstract During the May–June 2016 International Cooperative Air Quality Field Study in Korea (KORUS-AQ), light synoptic meteorological forcing facilitated Seoul metropolitan pollution outflow to reach the remote Taehwa Research Forest (TRF) site and cause regulatory exceedances of ozone on 24 days. Two of these severe pollution events are thoroughly examined. The first, occurring on 17 May 2016, tracks transboundary pollution transport exiting eastern China and the Yellow Sea, traversing the Seoul Metropolitan Area (SMA), and then reaching TRF in the afternoon hours with severely polluted conditions. This case study indicates that although outflow from China and the Yellow Sea were elevated with respect to chemically unperturbed conditions, the regulatory exceedance at TRF was directly linked in time, space, and altitude to urban Seoul emissions. The second case studied, which occurred on 9 June 2016, reveals that increased levels of biogenic emissions, in combination with amplified urban emissions, were associated with severe levels of pollution and a regulatory exceedance at TRF. In summary, domestic emissions may be causing more pollution than by transboundary pathways, which have been historically believed to be the major source of air pollution in South Korea. The case studies are assessed with multiple aircraft, model (photochemical and meteorological) simulations, in situ chemical sampling, and extensive ground-based profiling at TRF. These observations clearly identify TRF and the surrounding rural communities as receptor sites for severe pollution events associated with Seoul outflow, which will result in long-term negative effects to both human health and agriculture in the affected areas.
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 333
    Language English
    Publishing date 2019-04-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Sources and characteristics of summertime organic aerosol in the Colorado Front Range

    R. Bahreini / R. Ahmadov / S. A. McKeen / K. T. Vu / J. H. Dingle / E. C. Apel / D. R. Blake / N. Blake / T. L. Campos / C. Cantrell / F. Flocke / A. Fried / J. B. Gilman / A. J. Hills / R. S. Hornbrook / G. Huey / L. Kaser / B. M. Lerner / R. L. Mauldin /
    S. Meinardi / D. D. Montzka / D. Richter / J. R. Schroeder / M. Stell / D. Tanner / J. Walega / P. Weibring / A. Weinheimer

    Atmospheric Chemistry and Physics, Vol 18, Pp 8293-

    perspective from measurements and WRF-Chem modeling

    2018  Volume 8312

    Abstract: The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and ... ...

    Abstract The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA), with enhancement ratio of OA with respect to carbon monoxide (CO) reaching 0.085±0.003 µg m −3 ppbv −1 . At background mixing ratios of CO, up to ∼ 1.8 µg m −3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G) emissions was ∼ 40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF) confirmed a dominant contribution of secondary, oxygenated OA (OOA) in the boundary layer instead of fresh, hydrocarbon-like OA (HOA). Combinations of primary OA (POA) volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to < 5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA) in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA) production. Despite a lower production of bSOA in this scenario, contribution of bSOA to total SOA remained high at 40–54 %. ...
    Keywords Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 333
    Language English
    Publishing date 2018-06-01T00:00:00Z
    Publisher Copernicus Publications
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

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