One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate
Size distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here 1-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chlorid...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2014-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/14/9013/2014/acp-14-9013-2014.pdf |
| _version_ | 1828946317587513344 |
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| author | Q. Bian X. H. H. Huang J. Z. Yu |
| author_facet | Q. Bian X. H. H. Huang J. Z. Yu |
| author_sort | Q. Bian |
| collection | DOAJ |
| description | Size distribution data of major aerosol constituents are essential in source
apportioning of visibility degradation, testing and verification of air
quality models incorporating aerosols. We report here 1-year observations
of mass size distributions of major inorganic ions (sulfate, nitrate,
chloride, ammonium, sodium, potassium, magnesium and calcium) and oxalate at
a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of
size-segregated samples in the size range of 0.056–18 μm were
collected from March 2011 to February 2012. The size distributions of
sulfate, ammonium, potassium and oxalate were characterized by a dominant
droplet mode with a mass mean aerodynamic diameter (MMAD) in the range of
~ 0.7–0.9 μm. Oxalate had a slightly larger MMAD than
sulfate on days with temperatures above 22 °C as a result of the
process of volatilization and repartitioning. Nitrate was mostly dominated by
the coarse mode but enhanced presence in fine mode was detected on winter
days with lower temperature and lower concentrations of sea salt and soil
particles. This data set reveals an inversely proportional relationship
between the fraction of nitrate in the fine mode and product of the sum of
sodium and calcium in equivalent concentrations and the dissociation constant
of ammonium nitrate (i.e.,
(1/([Na<sup>+</sup>] + 2[Ca<sup>2+</sup>]) × (1/K<sub><i>e</i></sub>')) when
<i>P</i><sub>n_fine</sub> is significant (> 10%). The
seasonal variation observed for sea salt aerosol abundance, with lower values
in summer and winter, is possibly linked with the lower marine salinities in
these two seasons.
<br><br>
Positive matrix factorization was applied to estimate the relative
contributions of local formation and transport to the observed ambient
sulfate level through the use of the combined data sets of size-segregated
sulfate and select gaseous air pollutants. On average, the
regional/super-regional transport of air pollutants was the dominant source
at this receptor site, especially on high-sulfate days while local formation
processes contributed approximately 30% of the total sulfate. This work
provides field-measurement-based evidence important for understanding
both local photochemistry and regional/super-regional transport in order to
properly simulate sulfate aerosols in air quality models. |
| first_indexed | 2024-12-14T05:07:21Z |
| format | Article |
| id | doaj.art-7aff429248e54201a0c8683dc6a0c829 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-14T05:07:21Z |
| publishDate | 2014-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-7aff429248e54201a0c8683dc6a0c8292022-12-21T23:16:03ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242014-09-0114179013902710.5194/acp-14-9013-2014One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalateQ. Bian0X. H. H. Huang1J. Z. Yu2Department of Chemistry, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong KongInstitute of the Environment, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong KongDepartment of Chemistry, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong KongSize distribution data of major aerosol constituents are essential in source apportioning of visibility degradation, testing and verification of air quality models incorporating aerosols. We report here 1-year observations of mass size distributions of major inorganic ions (sulfate, nitrate, chloride, ammonium, sodium, potassium, magnesium and calcium) and oxalate at a coastal suburban receptor site in Hong Kong, China. A total of 43 sets of size-segregated samples in the size range of 0.056–18 μm were collected from March 2011 to February 2012. The size distributions of sulfate, ammonium, potassium and oxalate were characterized by a dominant droplet mode with a mass mean aerodynamic diameter (MMAD) in the range of ~ 0.7–0.9 μm. Oxalate had a slightly larger MMAD than sulfate on days with temperatures above 22 °C as a result of the process of volatilization and repartitioning. Nitrate was mostly dominated by the coarse mode but enhanced presence in fine mode was detected on winter days with lower temperature and lower concentrations of sea salt and soil particles. This data set reveals an inversely proportional relationship between the fraction of nitrate in the fine mode and product of the sum of sodium and calcium in equivalent concentrations and the dissociation constant of ammonium nitrate (i.e., (1/([Na<sup>+</sup>] + 2[Ca<sup>2+</sup>]) × (1/K<sub><i>e</i></sub>')) when <i>P</i><sub>n_fine</sub> is significant (> 10%). The seasonal variation observed for sea salt aerosol abundance, with lower values in summer and winter, is possibly linked with the lower marine salinities in these two seasons. <br><br> Positive matrix factorization was applied to estimate the relative contributions of local formation and transport to the observed ambient sulfate level through the use of the combined data sets of size-segregated sulfate and select gaseous air pollutants. On average, the regional/super-regional transport of air pollutants was the dominant source at this receptor site, especially on high-sulfate days while local formation processes contributed approximately 30% of the total sulfate. This work provides field-measurement-based evidence important for understanding both local photochemistry and regional/super-regional transport in order to properly simulate sulfate aerosols in air quality models.http://www.atmos-chem-phys.net/14/9013/2014/acp-14-9013-2014.pdf |
| spellingShingle | Q. Bian X. H. H. Huang J. Z. Yu One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate Atmospheric Chemistry and Physics |
| title | One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate |
| title_full | One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate |
| title_fullStr | One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate |
| title_full_unstemmed | One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate |
| title_short | One-year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in Hong Kong – Part 1: Inorganic ions and oxalate |
| title_sort | one year observations of size distribution characteristics of major aerosol constituents at a coastal receptor site in hong kong ndash part 1 inorganic ions and oxalate |
| url | http://www.atmos-chem-phys.net/14/9013/2014/acp-14-9013-2014.pdf |
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