Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 5.414
IF5.414
IF 5-year value: 5.958
IF 5-year
5.958
CiteScore value: 9.7
CiteScore
9.7
SNIP value: 1.517
SNIP1.517
IPP value: 5.61
IPP5.61
SJR value: 2.601
SJR2.601
Scimago H <br class='widget-line-break'>index value: 191
Scimago H
index
191
h5-index value: 89
h5-index89
Preprints
https://doi.org/10.5194/acp-2020-867
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2020-867
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  28 Aug 2020

28 Aug 2020

Review status
This preprint is currently under review for the journal ACP.

Measurement report: Aerosol hygroscopic properties extended to 600 nm in the urban environment

Chuanyang Shen1, Gang Zhao1,2, Weilun Zhao1, Ping Tian3, and Chunsheng Zhao1 Chuanyang Shen et al.
  • 1Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China
  • 2College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
  • 3Beijing Key Laboratory of Cloud, Precipitation and Atmospheric Water Resources, Beijing 100089, China

Abstract. Submicron particles larger than 300 nm dominate the aerosol light extinction and mass concentration in the atmosphere. The water uptake ability of this size range greatly influences the particle mass, visibility degradation and particle chemistry. However, most of previous field measurements on aerosol hygroscopicity are limited within 350 nm. In this study, the size-resolved aerosol hygroscopic properties over extended size range (50–600 nm) at 85 % relative humidity were investigated in Beijing winter from 27 November 2019 to 14 January 2020 using a Humidity Tandem Differential Mobility Analyser (HTDMA) instrument. The corresponding aerosol optical properties were also analyzed using the Mie scattering theory. Results show that the averaged probability distribution of GF (GF-PDF) is generally a constitute of a more-hygroscopic (MH) group and a less-hygroscopic (LH) group (including hydrophobic). For the particles larger than 300 nm, there exist a large fraction of LH group particles, resulting in an unexpected low hygroscopicity. During the development of pollution when particles are gradually aged and accumulated, the bulk hygroscopicity above 300 nm is enhanced significantly by the growth and expansion of MH group. This result is supported by previous chemical composition analysis and we give a more direct and detailed evidence from growth factor and mixing state aspects. Our calculations indicate that the optical contribution of particles larger than 300 nm constitutes about 2/3 of the total aerosol extinction. The large hygroscopic variation of aerosols above 300 nm will influence the light degradation comparably with the increase of aerosol loading in the low visibility haze events. Our studies highlight that the hygroscopic properties above 300 nm are complex and vary greatly with different pollution stages, therefore more field measurements and investigations need to be done in the future.

Chuanyang Shen et al.

Interactive discussion

Status: open (until 03 Nov 2020)
Status: open (until 03 Nov 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Chuanyang Shen et al.

Chuanyang Shen et al.

Viewed

Total article views: 143 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
95 46 2 143 0 0
  • HTML: 95
  • PDF: 46
  • XML: 2
  • Total: 143
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 28 Aug 2020)
Cumulative views and downloads (calculated since 28 Aug 2020)

Viewed (geographical distribution)

Total article views: 188 (including HTML, PDF, and XML) Thereof 187 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 29 Sep 2020
Publications Copernicus
Download
Short summary
Submicron particles larger than 300 nm dominate the aerosol light extinction and mass concentration in the urban environment. In this study, aerosol hygroscopic properties extended to 600 nm were investigated at an urban site. Our results find that there exists a large fraction of low hygroscopic group above 300 nm and the hygroscopicity in this size range is enhanced significantly with the development of pollution levels. The hygroscopicity variation contributes greatly to the low visibility.
Submicron particles larger than 300 nm dominate the aerosol light extinction and mass...
Citation
Altmetrics