A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system
Aerosol hygroscopicity is crucial for understanding roles of aerosol particles in atmospheric chemistry and aerosol climate effects. Light-scattering enhancement factor <i>f</i>(RH, <i>λ</i>) is one of the parameters describing aerosol hygroscopicity, which is defined as...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2017-06-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/17/6651/2017/acp-17-6651-2017.pdf |
| _version_ | 1818836887792517120 |
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| author | Y. Kuang C. Zhao J. Tao Y. Bian N. Ma G. Zhao |
| author_facet | Y. Kuang C. Zhao J. Tao Y. Bian N. Ma G. Zhao |
| author_sort | Y. Kuang |
| collection | DOAJ |
| description | Aerosol hygroscopicity is crucial for understanding roles
of aerosol particles in atmospheric chemistry and aerosol climate effects.
Light-scattering enhancement factor <i>f</i>(RH, <i>λ</i>) is one of the
parameters describing aerosol hygroscopicity, which is defined as
<i>f</i>(RH, <i>λ</i>) = <i>σ</i><sub>sp</sub>(RH, <i>λ</i>)∕<i>σ</i><sub>sp</sub>(dry, <i>λ</i>), where
<i>σ</i><sub>sp</sub>(RH, <i>λ</i>) or <i>σ</i><sub>sp</sub>(dry, <i>λ</i>) represents <i>σ</i><sub>sp</sub> at
wavelength <i>λ</i> under certain relative humidity (RH) or dry conditions.
Traditionally, an overall hygroscopicity parameter <i>κ</i> can be
retrieved from measured <i>f</i>(RH, <i>λ</i>), hereinafter referred to as
<i>κ</i><sub><i>f</i>(RH)</sub>, by combining concurrently measured particle number
size distribution (PNSD) and mass concentration of black carbon. In this
paper, a new method is proposed to directly derive <i>κ</i><sub><i>f</i>(RH)</sub>
based only on measurements from a three-wavelength humidified nephelometer
system. The advantage of this newly proposed approach is that
<i>κ</i><sub><i>f</i>(RH)</sub> can be estimated without any additional information
about PNSD and black carbon. This method is verified with measurements from
two different field campaigns. Values of <i>κ</i><sub><i>f</i>(RH)</sub> estimated
from this new method agree very well with those retrieved by using the
traditional method: all points lie near the 1 : 1 line and the square of
correlation coefficient between them is 0.99. The verification results
demonstrate that this newly proposed method of deriving
<i>κ</i><sub><i>f</i>(RH)</sub> is applicable at different sites and in seasons of
the North China Plain and might also be applicable in other regions around
the world. |
| first_indexed | 2024-12-19T03:13:45Z |
| format | Article |
| id | doaj.art-b8819dc504f94e9d85b83cb83b1d3df0 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-19T03:13:45Z |
| publishDate | 2017-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-b8819dc504f94e9d85b83cb83b1d3df02022-12-21T20:37:57ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-06-01176651666210.5194/acp-17-6651-2017A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer systemY. Kuang0C. Zhao1J. Tao2Y. Bian3N. Ma4G. Zhao5Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, ChinaDepartment of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, ChinaDepartment of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, ChinaState Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, ChinaLeibniz Institute for Tropospheric Research, Leipzig, GermanyDepartment of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, ChinaAerosol hygroscopicity is crucial for understanding roles of aerosol particles in atmospheric chemistry and aerosol climate effects. Light-scattering enhancement factor <i>f</i>(RH, <i>λ</i>) is one of the parameters describing aerosol hygroscopicity, which is defined as <i>f</i>(RH, <i>λ</i>) = <i>σ</i><sub>sp</sub>(RH, <i>λ</i>)∕<i>σ</i><sub>sp</sub>(dry, <i>λ</i>), where <i>σ</i><sub>sp</sub>(RH, <i>λ</i>) or <i>σ</i><sub>sp</sub>(dry, <i>λ</i>) represents <i>σ</i><sub>sp</sub> at wavelength <i>λ</i> under certain relative humidity (RH) or dry conditions. Traditionally, an overall hygroscopicity parameter <i>κ</i> can be retrieved from measured <i>f</i>(RH, <i>λ</i>), hereinafter referred to as <i>κ</i><sub><i>f</i>(RH)</sub>, by combining concurrently measured particle number size distribution (PNSD) and mass concentration of black carbon. In this paper, a new method is proposed to directly derive <i>κ</i><sub><i>f</i>(RH)</sub> based only on measurements from a three-wavelength humidified nephelometer system. The advantage of this newly proposed approach is that <i>κ</i><sub><i>f</i>(RH)</sub> can be estimated without any additional information about PNSD and black carbon. This method is verified with measurements from two different field campaigns. Values of <i>κ</i><sub><i>f</i>(RH)</sub> estimated from this new method agree very well with those retrieved by using the traditional method: all points lie near the 1 : 1 line and the square of correlation coefficient between them is 0.99. The verification results demonstrate that this newly proposed method of deriving <i>κ</i><sub><i>f</i>(RH)</sub> is applicable at different sites and in seasons of the North China Plain and might also be applicable in other regions around the world.http://www.atmos-chem-phys.net/17/6651/2017/acp-17-6651-2017.pdf |
| spellingShingle | Y. Kuang C. Zhao J. Tao Y. Bian N. Ma G. Zhao A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system Atmospheric Chemistry and Physics |
| title | A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| title_full | A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| title_fullStr | A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| title_full_unstemmed | A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| title_short | A novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| title_sort | novel method for deriving the aerosol hygroscopicity parameter based only on measurements from a humidified nephelometer system |
| url | http://www.atmos-chem-phys.net/17/6651/2017/acp-17-6651-2017.pdf |
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