TY - JOUR
T1 - Surface O3 photochemistry over the South China Sea
T2 - Application of a near-explicit chemical mechanism box model
AU - Wang, Yu
AU - Guo, Hai
AU - Zou, Shichun
AU - Lyu, Xiaopu
AU - Ling, Zhenhao
AU - Cheng, Hairong
AU - Zeren, Yangzong
PY - 2018/3
Y1 - 2018/3
N2 - A systematic field measurement was conducted at an island site (Wanshan Island, WSI) over the South China Sea (SCS) in autumn 2013. It was observed that mixing ratios of O3 and its precursors (such as volatile organic compounds (VOCs), nitrogen oxides (NOx = NO + NO2) and carbon monoxide (CO)) showed significant differences on non-episode days and episode days. Additional knowledge was gained when a photochemical box model incorporating the Master Chemical Mechanism (PBM-MCM) was applied to further investigate the differences/similarities of O3 photochemistry between non-episode and episode days, in terms of O3-precursor relationship, atmospheric photochemical reactivity and O3 production. The simulation results revealed that, from non-O3 episode days to episode days, 1) O3 production changed from both VOC and NOx-limited (transition regime) to VOC-limited; 2) OH radicals increased and photochemical reaction cycling processes accelerated; and 3) both O3 production and destruction rates increased significantly, resulting in an elevated net O3 production over the SCS. The findings indicate the complexity of O3 pollution over the SCS. Elevation of maritime O3 and its precursors was attributable to the transport of polluted continental air, implying impact of human activities on atmospheric composition above the SCS.
AB - A systematic field measurement was conducted at an island site (Wanshan Island, WSI) over the South China Sea (SCS) in autumn 2013. It was observed that mixing ratios of O3 and its precursors (such as volatile organic compounds (VOCs), nitrogen oxides (NOx = NO + NO2) and carbon monoxide (CO)) showed significant differences on non-episode days and episode days. Additional knowledge was gained when a photochemical box model incorporating the Master Chemical Mechanism (PBM-MCM) was applied to further investigate the differences/similarities of O3 photochemistry between non-episode and episode days, in terms of O3-precursor relationship, atmospheric photochemical reactivity and O3 production. The simulation results revealed that, from non-O3 episode days to episode days, 1) O3 production changed from both VOC and NOx-limited (transition regime) to VOC-limited; 2) OH radicals increased and photochemical reaction cycling processes accelerated; and 3) both O3 production and destruction rates increased significantly, resulting in an elevated net O3 production over the SCS. The findings indicate the complexity of O3 pollution over the SCS. Elevation of maritime O3 and its precursors was attributable to the transport of polluted continental air, implying impact of human activities on atmospheric composition above the SCS.
KW - Ozone
KW - Photochemical box model
KW - Photochemistry
KW - South China Sea
KW - VOCs
UR - http://www.scopus.com/inward/record.url?scp=85034735559&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2017.11.001
DO - 10.1016/j.envpol.2017.11.001
M3 - Journal article
C2 - 29175477
AN - SCOPUS:85034735559
SN - 0269-7491
VL - 234
SP - 155
EP - 166
JO - Environmental Pollution
JF - Environmental Pollution
ER -