New insight into the spatiotemporal variability and source apportionments of C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates (RONO<sub>2</sub>) were measured concurrently at a mountain site, Tai Mo Shan (TMS), and an urban site, Tsuen Wan (TW), at the base of the same mountain in Hong Kong from September to November 2010. Although the levels...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/16/8141/2016/acp-16-8141-2016.pdf |
| _version_ | 1828161228907741184 |
|---|---|
| author | Z. Ling Z. Ling H. Guo I. J. Simpson S. M. Saunders S. H. M. Lam S. H. M. Lam X. Lyu D. R. Blake |
| author_facet | Z. Ling Z. Ling H. Guo I. J. Simpson S. M. Saunders S. H. M. Lam S. H. M. Lam X. Lyu D. R. Blake |
| author_sort | Z. Ling |
| collection | DOAJ |
| description | C<sub>1</sub>–C<sub>4</sub> alkyl nitrates (RONO<sub>2</sub>) were measured concurrently at a
mountain site, Tai Mo Shan (TMS), and an urban site, Tsuen Wan (TW), at
the base of the same mountain in Hong Kong from September to November 2010.
Although the levels of parent hydrocarbons were much lower at TMS
(<i>p</i> < 0.05), similar alkyl nitrate levels were found at both sites
regardless of the elevation difference, suggesting various source
contributions of alkyl nitrates at the two sites. Prior to using a positive
matrix factorization (PMF) model, the data at TW were divided into "meso"
and "non-meso" scenarios for the investigation of source apportionments
with the influence of mesoscale circulation and regional transport,
respectively. Secondary formation was the prominent contributor of alkyl
nitrates in the meso scenario (60 ± 2 %,
60.2 ± 1.2 pptv), followed by biomass burning and oceanic emissions,
while biomass burning and secondary formation made comparable contributions
to alkyl nitrates in the non-meso scenario, highlighting the strong
emissions of biomass burning in the inland Pearl River delta (PRD) region. In
contrast to TW, the alkyl nitrate levels measured at TMS mainly resulted from
the photooxidation of the parent hydrocarbons at TW during mesoscale
circulation, i.e., valley breezes, corresponding to 52–86 % of the alkyl
nitrate levels at TMS. Furthermore, regional transport from the inland PRD
region made significant contributions to the levels of alkyl nitrates
(∼ 58–82 %) at TMS in the non-meso scenario, resulting in
similar levels of alkyl nitrates observed at the two sites. The simulation of
secondary formation pathways using a photochemical box model found that the
reaction of alkyl peroxy radicals (RO<sub>2</sub>) with nitric oxide (NO) dominated
the formation of RONO<sub>2</sub> at both sites, and the formation of alkyl
nitrates contributed negatively to O<sub>3</sub> production, with average reduction
rates of 4.1 and 4.7 pptv pptv<sup>−1</sup> at TMS and TW, respectively. |
| first_indexed | 2024-04-12T00:33:59Z |
| format | Article |
| id | doaj.art-56a8ecb2911643aebd668aee8d8d21a3 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-12T00:33:59Z |
| publishDate | 2016-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-56a8ecb2911643aebd668aee8d8d21a32022-12-22T03:55:12ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242016-07-01168141815610.5194/acp-16-8141-2016New insight into the spatiotemporal variability and source apportionments of C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong KongZ. Ling0Z. Ling1H. Guo2I. J. Simpson3S. M. Saunders4S. H. M. Lam5S. H. M. Lam6X. Lyu7D. R. Blake8School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, ChinaAir Quality Studies, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong KongAir Quality Studies, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong KongDepartment of Chemistry, University of California at Irvine, California, USASchool of Chemistry and Biochemistry, University of Western Australia, Perth, Western Australia, AustraliaSchool of Chemistry and Biochemistry, University of Western Australia, Perth, Western Australia, AustraliaPacific Environment Limited, Perth, Western Australia, AustraliaAir Quality Studies, Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, Hong KongDepartment of Chemistry, University of California at Irvine, California, USAC<sub>1</sub>–C<sub>4</sub> alkyl nitrates (RONO<sub>2</sub>) were measured concurrently at a mountain site, Tai Mo Shan (TMS), and an urban site, Tsuen Wan (TW), at the base of the same mountain in Hong Kong from September to November 2010. Although the levels of parent hydrocarbons were much lower at TMS (<i>p</i> < 0.05), similar alkyl nitrate levels were found at both sites regardless of the elevation difference, suggesting various source contributions of alkyl nitrates at the two sites. Prior to using a positive matrix factorization (PMF) model, the data at TW were divided into "meso" and "non-meso" scenarios for the investigation of source apportionments with the influence of mesoscale circulation and regional transport, respectively. Secondary formation was the prominent contributor of alkyl nitrates in the meso scenario (60 ± 2 %, 60.2 ± 1.2 pptv), followed by biomass burning and oceanic emissions, while biomass burning and secondary formation made comparable contributions to alkyl nitrates in the non-meso scenario, highlighting the strong emissions of biomass burning in the inland Pearl River delta (PRD) region. In contrast to TW, the alkyl nitrate levels measured at TMS mainly resulted from the photooxidation of the parent hydrocarbons at TW during mesoscale circulation, i.e., valley breezes, corresponding to 52–86 % of the alkyl nitrate levels at TMS. Furthermore, regional transport from the inland PRD region made significant contributions to the levels of alkyl nitrates (∼ 58–82 %) at TMS in the non-meso scenario, resulting in similar levels of alkyl nitrates observed at the two sites. The simulation of secondary formation pathways using a photochemical box model found that the reaction of alkyl peroxy radicals (RO<sub>2</sub>) with nitric oxide (NO) dominated the formation of RONO<sub>2</sub> at both sites, and the formation of alkyl nitrates contributed negatively to O<sub>3</sub> production, with average reduction rates of 4.1 and 4.7 pptv pptv<sup>−1</sup> at TMS and TW, respectively.https://www.atmos-chem-phys.net/16/8141/2016/acp-16-8141-2016.pdf |
| spellingShingle | Z. Ling Z. Ling H. Guo I. J. Simpson S. M. Saunders S. H. M. Lam S. H. M. Lam X. Lyu D. R. Blake New insight into the spatiotemporal variability and source apportionments of C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong Atmospheric Chemistry and Physics |
| title | New insight into the spatiotemporal variability and source apportionments of
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong |
| title_full | New insight into the spatiotemporal variability and source apportionments of
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong |
| title_fullStr | New insight into the spatiotemporal variability and source apportionments of
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong |
| title_full_unstemmed | New insight into the spatiotemporal variability and source apportionments of
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong |
| title_short | New insight into the spatiotemporal variability and source apportionments of
C<sub>1</sub>–C<sub>4</sub> alkyl nitrates in Hong Kong |
| title_sort | new insight into the spatiotemporal variability and source apportionments of c sub 1 sub c sub 4 sub alkyl nitrates in hong kong |
| url | https://www.atmos-chem-phys.net/16/8141/2016/acp-16-8141-2016.pdf |
| work_keys_str_mv | AT zling newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT zling newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT hguo newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT ijsimpson newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT smsaunders newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT shmlam newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT shmlam newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT xlyu newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong AT drblake newinsightintothespatiotemporalvariabilityandsourceapportionmentsofcsub1subcsub4subalkylnitratesinhongkong |