Impacts of biogenic isoprene emission on ozone air quality in the Seoul metropolitan area

Biogenic isoprene emission;Ozone air quality;Urban area;Urban breeze circulation;WRF model;CMAQ model;550

자연과학대학 지구환경과학부 ;

University:서울대학교 대학원

关键词: Biogenic isoprene emission;    Ozone air quality;    Urban area;    Urban breeze circulation;    WRF model;    CMAQ model;    550;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/131371/1/000000013386.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

The impacts of biogenic isoprene emission on ozone air quality and the effect of interaction between biogenic isoprene emission and urban breeze circulation on ozone air quality during an episode of weak synoptic forcing in the Seoul metropolitan area, South Korea, are investigated using WRF model coupled with Seoul National University Urban Canopy Model and CMAQ model. The biogenic isoprene emission increases daily maximum ozone concentration by 37 ppb in the urban area. The biogenic isoprene emitted from the surrounding region of Seoul has larger impacts on the ozone concentration in the urban area than the biogenic isoprene emitted from the Seoul region. The gas-phase chemistry is the most important process to the ozone concentration in the daytime when the urban breezecirculation is well developed in the presence of the biogenic isoprene emission. The lifetime of isoprene is not long enough (around 30 minutes) to directly affect ozone concentration in the urban area. Rather thanisoprene, MA_PAN which is produced from isoprene by gas-phase chemistry links the biogenic isoprene emitted from the surrounding region and ozone in the urban area. MA_PAN produced in the surrounding area is transported into the urban area and dissociate into other species which produce ozone in the urban area. Urban breeze circulation is an important atmospheric phenomenon that affects ozone concentration in the urban area. When the urban and industrial surfaces are artificially replaced with the cropland surface, urban breeze circulation is not well developed. In this case, theozone concentration generally decreases by about 10% and the contribution of gas-phase chemistry to the ozone concentration is decreased in the urban area. It is caused by the decrement of transport of the ozone precursor from the surrounding area to the urban area. The results from this study can be give some insight about how biogenic isoprene affect the ozone concentration in the urban area.