TY - JOUR
T1 - Meteorological and chemical factors controlling ozone formation in Seoul during MAPS-Seoul 2015
AU - Kim, Heejeong
AU - Choi, Woo Chul
AU - Rhee, Ho Jun
AU - Suh, Inseon
AU - Lee, Meehye
AU - Blake, Donald R.
AU - Kim, Saewung
AU - Jung, Jinsang
AU - Lee, Gangwoong
AU - Kim, Deug Soo
AU - Park, Seung Myung
AU - Ahn, Junyoung
AU - Lee, Sang Deok
N1 - Funding Information:
This study was supported by the National Institute of Environmental Research (NIER) and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science, Information, and Communications Technology & Future Planning (NRF-2017R1A2B4012143). Special thanks should be given to Dr. Blake’s group at UC Irvine for the VOC measurements. All authors would like to thank NIER people for their hard work in keeping the measurement facilities and KIST for providing the site for this study.
PY - 2018/9
Y1 - 2018/9
N2 - To understand the chemical mechanisms of controlling factors in ozone (O3) formation in early summer in Seoul, a comprehensive study encompassing measurement and modeling was conducted under the Megacity Air Pollution Study-Seoul (MAPS-Seoul) campaign. From May 18 to June 12, 2015, O3 and peroxyacetyl nitrate (PAN) were measured, along with their precursors, including NOx and volatile organic compounds (VOCs), at the Korea Institute of Science and Technology, located in northeast Seoul. VOCs were sampled in a canister twice a day (at 09:30 and 15:00) and analyzed via gas chromatography. The meteorological conditions and chemical regimes of the air masses were clearly distinguished during the study period. In May, NOx concentrations were higher with more pronounced diurnal cycles of precursors and O3 under constant westerly winds. By contrast, stagnant conditions developed in June, which reduced the inflow of primary emissions from the downtown area but increased the influence from the neighboring forest under high temperatures. As a result, the ratio of O3 to odd oxygen was higher in June, indicating a less efficient removal of O3 by NOx. In the same context, the air mass was chemically more aged with a higher NO2/NOx ratio and enhanced OH reactivity of oxygenated and biogenic VOCs in June. The overall measurement results suggest that O3 formation is slightly more sensitive to VOCs than to NOx in Seoul during this season, when O3 concentrations are the highest of the year.
AB - To understand the chemical mechanisms of controlling factors in ozone (O3) formation in early summer in Seoul, a comprehensive study encompassing measurement and modeling was conducted under the Megacity Air Pollution Study-Seoul (MAPS-Seoul) campaign. From May 18 to June 12, 2015, O3 and peroxyacetyl nitrate (PAN) were measured, along with their precursors, including NOx and volatile organic compounds (VOCs), at the Korea Institute of Science and Technology, located in northeast Seoul. VOCs were sampled in a canister twice a day (at 09:30 and 15:00) and analyzed via gas chromatography. The meteorological conditions and chemical regimes of the air masses were clearly distinguished during the study period. In May, NOx concentrations were higher with more pronounced diurnal cycles of precursors and O3 under constant westerly winds. By contrast, stagnant conditions developed in June, which reduced the inflow of primary emissions from the downtown area but increased the influence from the neighboring forest under high temperatures. As a result, the ratio of O3 to odd oxygen was higher in June, indicating a less efficient removal of O3 by NOx. In the same context, the air mass was chemically more aged with a higher NO2/NOx ratio and enhanced OH reactivity of oxygenated and biogenic VOCs in June. The overall measurement results suggest that O3 formation is slightly more sensitive to VOCs than to NOx in Seoul during this season, when O3 concentrations are the highest of the year.
KW - MAPS-Seoul
KW - Meteorological condition
KW - NO
KW - O formation
KW - VOCs
UR - http://www.scopus.com/inward/record.url?scp=85055481410&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055481410&partnerID=8YFLogxK
U2 - 10.4209/aaqr.2017.11.0445
DO - 10.4209/aaqr.2017.11.0445
M3 - Article
AN - SCOPUS:85055481410
VL - 18
SP - 2274
EP - 2286
JO - Aerosol and Air Quality Research
JF - Aerosol and Air Quality Research
SN - 1680-8584
IS - 9
ER -