TY - JOUR
T1 - Spatiotemporal variation of ozone precursors and ozone formation in Hong Kong
T2 - Grid field measurement and modelling study
AU - Lyu, X. P.
AU - Liu, M.
AU - Guo, H.
AU - Ling, Z. H.
AU - Wang, Y.
AU - Louie, P. K. K.
AU - Luk, C. W. Y.
N1 - Funding Information:
We thank HKEPD for providing us the data. This study was supported by the Research Grants Council of the Hong Kong Special Administrative Region via grants ( PolyU5154/13E , PolyU152052/14E , CRF/C5022-14G and CRF/C5004-15E ), the HKPolyU PhD scholarship (project #RTUP) , and the HKPolyU internal grants (1-ZVCX and G-YBHT). This study is partly supported by the National Natural Science Foundation of China ( 41275122 ).
Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/11
Y1 - 2016/11
N2 - Grid field measurements of volatile organic compounds (VOCs) covering the entire territory of Hong Kong were simultaneously carried out twice daily on 27 September 2013 and 24 September 2014, respectively, to advance our understanding on the spatiotemporal variations of VOCs and ozone (O3) formation, the factors controlling O3 formation and the efficacy of a control measure in Hong Kong. From before to after the control measure on liquefied petroleum gas (LPG) fueled vehicles, the VOCs originated from LPG vehicle exhaust deceased from 41.3 ± 1.2 μg/m3 (49.7 ± 1.5%) to 32.8 ± 1.4 μg/m3 (38.8 ± 1.7%) (p < 0.05). In contrast, the contribution to VOCs made by gasoline and diesel vehicle exhaust and solvent usage increased (p < 0.05). VOCs and nitric oxide (NO) in LPG source experienced the highest reductions at the roadside sites, while the variations were not significant at the urban and new town sites (p > 0.05). For O3 production, LPG vehicle exhaust generally made a negative contribution (− 0.17 ± 0.06 ppbv) at the roadside sites, however it turned to a slightly positive contribution (0.004 ± 0.038 ppbv) after the control measure. At the urban sites, although the reductions of VOCs and NO were minor (p > 0.05), O3 produced by LPG vehicle significantly reduced from 4.19 ± 1.92 ppbv to 0.95 ± 0.38 ppbv (p < 0.05). Meanwhile, O3 produced by LPG at the new town sites remained stable. The analysis of O3-precursor relationships revealed that alkenes and aromatics were the main species limiting roadside O3 formation, while aromatics were the most predominant controlling factor at urban and new town sites. In contrast, isoprene and sometimes NOx limited the O3 formation in rural environment.
AB - Grid field measurements of volatile organic compounds (VOCs) covering the entire territory of Hong Kong were simultaneously carried out twice daily on 27 September 2013 and 24 September 2014, respectively, to advance our understanding on the spatiotemporal variations of VOCs and ozone (O3) formation, the factors controlling O3 formation and the efficacy of a control measure in Hong Kong. From before to after the control measure on liquefied petroleum gas (LPG) fueled vehicles, the VOCs originated from LPG vehicle exhaust deceased from 41.3 ± 1.2 μg/m3 (49.7 ± 1.5%) to 32.8 ± 1.4 μg/m3 (38.8 ± 1.7%) (p < 0.05). In contrast, the contribution to VOCs made by gasoline and diesel vehicle exhaust and solvent usage increased (p < 0.05). VOCs and nitric oxide (NO) in LPG source experienced the highest reductions at the roadside sites, while the variations were not significant at the urban and new town sites (p > 0.05). For O3 production, LPG vehicle exhaust generally made a negative contribution (− 0.17 ± 0.06 ppbv) at the roadside sites, however it turned to a slightly positive contribution (0.004 ± 0.038 ppbv) after the control measure. At the urban sites, although the reductions of VOCs and NO were minor (p > 0.05), O3 produced by LPG vehicle significantly reduced from 4.19 ± 1.92 ppbv to 0.95 ± 0.38 ppbv (p < 0.05). Meanwhile, O3 produced by LPG at the new town sites remained stable. The analysis of O3-precursor relationships revealed that alkenes and aromatics were the main species limiting roadside O3 formation, while aromatics were the most predominant controlling factor at urban and new town sites. In contrast, isoprene and sometimes NOx limited the O3 formation in rural environment.
KW - VOCs
KW - Source apportionment
KW - Photochemical O3
KW - Eulerian box model
KW - MCM
UR - http://www.scopus.com/inward/record.url?scp=84989898358&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2016.06.214
DO - 10.1016/j.scitotenv.2016.06.214
M3 - Journal article
C2 - 27387808
AN - SCOPUS:84989898358
SN - 0048-9697
VL - 569-570
SP - 1341
EP - 1349
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -
