Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong
Mass-concentration-based particle size distributions measured by a high-resolution aerosol mass spectrometer were systematically analyzed to assess long and short-term temporal characteristics of ambient particle size distributions sampled at a typical urban environment close to emission sources...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/13605/2017/acp-17-13605-2017.pdf |
| _version_ | 1818573628534423552 |
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| author | B. P. Lee H. Wang C. K. Chan C. K. Chan |
| author_facet | B. P. Lee H. Wang C. K. Chan C. K. Chan |
| author_sort | B. P. Lee |
| collection | DOAJ |
| description | Mass-concentration-based particle size distributions measured by a
high-resolution aerosol mass spectrometer were systematically analyzed to
assess long and short-term temporal characteristics of ambient particle size
distributions sampled at a typical urban environment close to emission
sources and a suburban coastal site representing a regional and local
pollution receptor location in Hong Kong. Measured distributions were
bimodal and deconvoluted into submodes, which were analyzed for day-to-day
variations and diurnal variations.<br><br>
Traffic and cooking emissions at the urban site contributed substantially to
particle mass in both modes, while notable decreases in mass median diameters
were limited to the morning rush hour. Inorganic particle components
displayed varying diurnal behavior, including nocturnal nitrate formation and
daytime photochemical formation evident in both modes. Suburban particle size
distributions exhibited notable seasonal disparities with differing influence
of local formation, particularly in spring and summer, and transport which
dominated in the fall season leading to notably higher sulfate and organic
accumulation-mode particle concentrations. Variations in particle mixing
state were evaluated by comparison of interspecies mass median diameter
trends at both measurement sites. Internal mixing was prevalent in the
accumulation mode in spring at the urban site, while greater frequency of
time periods with external mixing of particle populations comprising
different fractions of organic constituents was observed in summer. At the
suburban site, sulfate and nitrate in the accumulation mode more frequently
exhibited differing particle size distributions in all seasons, signifying a
greater extent of external mixing.<br><br>
At the urban site, periods of greater submicron inorganic mass concentrations
were more likely to be caused by increases in both Aitken- and accumulation-mode particle mass in summer, while at the suburban receptor location, organic
and nitrate Aitken-mode particle mass contributed more regularly to higher
total submicron species mass concentrations in most seasons (spring, summer,
and winter). |
| first_indexed | 2024-12-15T00:13:53Z |
| format | Article |
| id | doaj.art-fd4b225f37be4545b68289125a7c031c |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-15T00:13:53Z |
| publishDate | 2017-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-fd4b225f37be4545b68289125a7c031c2022-12-21T22:42:29ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-11-0117136051362410.5194/acp-17-13605-2017Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong KongB. P. Lee0H. Wang1C. K. Chan2C. K. Chan3School of Energy and Environment, City University of Hong Kong, Hong Kong, ChinaDivision of Environment, Hong Kong University of Science and Technology, Hong Kong, ChinaSchool of Energy and Environment, City University of Hong Kong, Hong Kong, ChinaDivision of Environment, Hong Kong University of Science and Technology, Hong Kong, ChinaMass-concentration-based particle size distributions measured by a high-resolution aerosol mass spectrometer were systematically analyzed to assess long and short-term temporal characteristics of ambient particle size distributions sampled at a typical urban environment close to emission sources and a suburban coastal site representing a regional and local pollution receptor location in Hong Kong. Measured distributions were bimodal and deconvoluted into submodes, which were analyzed for day-to-day variations and diurnal variations.<br><br> Traffic and cooking emissions at the urban site contributed substantially to particle mass in both modes, while notable decreases in mass median diameters were limited to the morning rush hour. Inorganic particle components displayed varying diurnal behavior, including nocturnal nitrate formation and daytime photochemical formation evident in both modes. Suburban particle size distributions exhibited notable seasonal disparities with differing influence of local formation, particularly in spring and summer, and transport which dominated in the fall season leading to notably higher sulfate and organic accumulation-mode particle concentrations. Variations in particle mixing state were evaluated by comparison of interspecies mass median diameter trends at both measurement sites. Internal mixing was prevalent in the accumulation mode in spring at the urban site, while greater frequency of time periods with external mixing of particle populations comprising different fractions of organic constituents was observed in summer. At the suburban site, sulfate and nitrate in the accumulation mode more frequently exhibited differing particle size distributions in all seasons, signifying a greater extent of external mixing.<br><br> At the urban site, periods of greater submicron inorganic mass concentrations were more likely to be caused by increases in both Aitken- and accumulation-mode particle mass in summer, while at the suburban receptor location, organic and nitrate Aitken-mode particle mass contributed more regularly to higher total submicron species mass concentrations in most seasons (spring, summer, and winter).https://www.atmos-chem-phys.net/17/13605/2017/acp-17-13605-2017.pdf |
| spellingShingle | B. P. Lee H. Wang C. K. Chan C. K. Chan Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong Atmospheric Chemistry and Physics |
| title | Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong |
| title_full | Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong |
| title_fullStr | Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong |
| title_full_unstemmed | Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong |
| title_short | Diurnal and day-to-day characteristics of ambient particle mass size distributions from HR-ToF-AMS measurements at an urban site and a suburban site in Hong Kong |
| title_sort | diurnal and day to day characteristics of ambient particle mass size distributions from hr tof ams measurements at an urban site and a suburban site in hong kong |
| url | https://www.atmos-chem-phys.net/17/13605/2017/acp-17-13605-2017.pdf |
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