The impacts of biogenic isoprene emission on ozone (O3) air quality during an episode under weak synoptic forcing in the Seoul metropolitan area (SMA), Republic of Korea, are investigated using the Community Multiscale Air Quality (CMAQ) modeling system coupled with the Weather Research and Forecasting (WRF) model. Simulations with different biogenic isoprene emission scenarios show that the impact of biogenic isoprene emission on the daily maximum O3 concentration is as high as 37ppb in the Seoul region. The O3 concentration in the Seoul region is significantly increased by the biogenic isoprene emission from the surrounding region compared to that from within the Seoul region. In addition, the gas-phase chemistry is found to be the most important process for O3 concentration in the Seoul region in the presence of the biogenic isoprene emission from the surrounding region. While isoprene is not enough to influence O3 concentration directly due to its short lifetime, the transport of isoprene oxidation products plays a crucial role in increasing O3 concentration in the Seoul region. Through the process analysis, peroxy methacryloyl nitrate (MPAN) as well as formaldehyde (HCHO) and acetaldehyde (CCHO) is also identified as the important precursor that links biogenic isoprene emission from the surrounding region to O3 concentration in the Seoul region. After transported by daytime local circulations, the chemistry of isoprene oxidation products contributes to O3 formation in the Seoul region.
|Number of pages||11|
|Publication status||Published - 2014 Oct|
Bibliographical noteFunding Information:
The authors are grateful to two anonymous reviewers for providing valuable comments that led to the improvements of the original manuscript. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Ministry of Science, ICT and Future Planning (MSIP) (No. 2011–0017041 ).
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Atmospheric Science