the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 23 Apr 2024
Hygroscopic Growth and Activation Changed Submicron Aerosol Composition and Properties in North China Plain
Abstract. Aerosol hygroscopic growth and activation under high relative humidity (RH) conditions significantly influence the physicochemical properties of submicron aerosols (PM1). However, this process remains poorly characterized due to limited measurements. To address this gap, we deployed an advanced aerosol-fog sampling system that automatically switched between PM1, PM2.5, and TSP inlets at a rural site in the North China Plain in cold season. The results revealed that aerosol swelling due to water vapor uptake influenced aerosol sampling under high RH conditions by shifting the cut-off size of impactors. Under subsaturated high RH (> 90 %), over 25 % of aerosol mass with dry diameters below 1 μm resided in supermicron ranges, while in supersaturated foggy conditions, more than 70 % submicron aerosol migrated to supermicron ranges. Hygroscopic growth and activation particularly affected highly hydrophilic inorganic salts shifting a significant mass submicron sulfate and nitrate particles to supermicron ranges, with 27 – 33 % under 95 % ≤ RH ≤ 99 %, and 65.5 % in supersaturated foggy conditions. Moreover, more than 10 % of submicron biomass burning organic aerosols grew beyond 2.5 μm during fog events, while fossil fuel-related OA (FFOA) remained dominantly in submicron ranges, suggesting inefficient aqueous conversion of FFOA. The two SOA factors (OOA1 and OOA2) behaved differently under supersaturated conditions, with OOA2 exhibiting a higher activated fraction despite a lower oxygen-to-carbon ratio. A substantial increase in organic nitrate and organosulfur mass concentrations in activated droplets during fog events suggested aqueous conversions and formations of brown carbon with potential radiative impacts. Overall, our study highlights remarkably different aqueous processing of primary and secondary PM1 aerosol components under distinct ambient RH conditions.
-
Notice on discussion status
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
-
Preprint
(1072 KB)
-
Supplement
(969 KB)
-
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(1072 KB) - Metadata XML
-
Supplement
(969 KB) - BibTeX
- EndNote
- Final revised paper
Journal article(s) based on this preprint
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2024-998', Anonymous Referee #1, 09 May 2024
General comments:
This study used an advanced aerosol-fog sampling system to directly investigate the impacts of aerosol hygroscopic growth and activation processes on physical and chemical properties of submicron aerosols which is rarely done before. Presented results revealed significant shifts in aerosol size distributions and composition under both subsaturated and supersaturated high RH conditions, with more than 70% submicron aerosol migrated to supermicron ranges in foggy conditions, and over 25% of aerosol mass with dry diameters below 1 μm resided in supermicron ranges under subsaturated high RH (> 90%), shedding new insights into aerosol sampling and aerosol physical properties in foggy/cloudy and high RH conditions. Moreover, simultaneous measurements of aerosol chemical compositions shedding new insights into hygroscopic and activation properties of different aerosols types, which is important implications in both aerosol/cloud aqueous chemistry and cloud microphysics. In general, I think this manuscript is well organized and presented direct measurements of aerosol hygroscopic and activation processes with the view of aerosol size and chemistry which is very useful for aerosol and fog/cloud community，therefore suggest acceptance after minor revisions.
Minor comments:
- Emphasize the broader implications of the research findings for aerosol/cloud science and atmospheric chemistry in the abstract
- Explicitly state the research objectives or questions towards the end of the introduction to guide readers on what to expect from the study. This helps to focus the reader's attention and provides a roadmap for the rest of the manuscript. Current version discussed too much on aerosol chemical compositions, however, discussions about current understandings of how aerosol hygroscopic growth and activation impacts on aerosol submicron aerosol compositions is relatively few.
Citation: https://doi.org/10.5194/egusphere-2024-998-RC1 -
AC1: 'Reply on RC1', Ye Kuang, 11 Jul 2024
Response to Reviewer #1
General comments:
This study used an advanced aerosol-fog sampling system to directly investigate the impacts of aerosol hygroscopic growth and activation processes on physical and chemical properties of submicron aerosols which is rarely done before. Presented results revealed significant shifts in aerosol size distributions and composition under both subsaturated and supersaturated high RH conditions, with more than 70% submicron aerosol migrated to supermicron ranges in foggy conditions, and over 25% of aerosol mass with dry diameters below 1 μm resided in supermicron ranges under subsaturated high RH (> 90%), shedding new insights into aerosol sampling and aerosol physical properties in foggy/cloudy and high RH conditions. Moreover, simultaneous measurements of aerosol chemical compositions shedding new insights into hygroscopic and activation properties of different aerosols types, which is important implications in both aerosol/cloud aqueous chemistry and cloud microphysics. In general, I think this manuscript is well organized and presented direct measurements of aerosol hygroscopic and activation processes with the view of aerosol size and chemistry which is very useful for aerosol and fog/cloud community，therefore suggest acceptance after minor revisions.
We thank the reviewer’s positive comments.
Minor comments:
Emphasize the broader implications of the research findings for aerosol/cloud science and atmospheric chemistry in the abstract
Corrected.
Following the reviewer’s comments, we added
“Overall, our study highlights remarkably different cloud and fog processing behaviors between primary and secondary aerosols, which would benefit a better understanding of aerosol-cloud interactions under distinct atmospheric conditions.”
Explicitly state the research objectives or questions towards the end of the introduction to guide readers on what to expect from the study. This helps to focus the reader's attention and provides a roadmap for the rest of the manuscript. Current version discussed too much on aerosol chemical compositions, however, discussions about current understandings of how aerosol hygroscopic growth and activation impacts on aerosol submicron aerosol compositions is relatively few.
We thank the reviewer’s comments. Indeed, we have expanded our discussion in the introduction to further explore how RH impacts aerosol chemical compositions, as only a limited number of studies have directly investigated the effects of aerosol hygroscopic growth and activation on aerosol size or chemical compositions.
To better clarify this point, the following sentences are added in the first paragraph:
“Most current studies primarily focus on the impact of RH on aerosol chemical compositions, with only a limited number of studies directly quantifying how aerosol hygroscopic growth and activation affect size and/or chemical compositions of aerosol”
-
RC2: 'Comment on egusphere-2024-998', Anonymous Referee #2, 21 May 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-998/egusphere-2024-998-RC2-supplement.pdf
- AC2: 'Reply on RC2', Ye Kuang, 11 Jul 2024
Interactive discussion
Status: closed
-
RC1: 'Comment on egusphere-2024-998', Anonymous Referee #1, 09 May 2024
General comments:
This study used an advanced aerosol-fog sampling system to directly investigate the impacts of aerosol hygroscopic growth and activation processes on physical and chemical properties of submicron aerosols which is rarely done before. Presented results revealed significant shifts in aerosol size distributions and composition under both subsaturated and supersaturated high RH conditions, with more than 70% submicron aerosol migrated to supermicron ranges in foggy conditions, and over 25% of aerosol mass with dry diameters below 1 μm resided in supermicron ranges under subsaturated high RH (> 90%), shedding new insights into aerosol sampling and aerosol physical properties in foggy/cloudy and high RH conditions. Moreover, simultaneous measurements of aerosol chemical compositions shedding new insights into hygroscopic and activation properties of different aerosols types, which is important implications in both aerosol/cloud aqueous chemistry and cloud microphysics. In general, I think this manuscript is well organized and presented direct measurements of aerosol hygroscopic and activation processes with the view of aerosol size and chemistry which is very useful for aerosol and fog/cloud community，therefore suggest acceptance after minor revisions.
Minor comments:
- Emphasize the broader implications of the research findings for aerosol/cloud science and atmospheric chemistry in the abstract
- Explicitly state the research objectives or questions towards the end of the introduction to guide readers on what to expect from the study. This helps to focus the reader's attention and provides a roadmap for the rest of the manuscript. Current version discussed too much on aerosol chemical compositions, however, discussions about current understandings of how aerosol hygroscopic growth and activation impacts on aerosol submicron aerosol compositions is relatively few.
Citation: https://doi.org/10.5194/egusphere-2024-998-RC1 -
AC1: 'Reply on RC1', Ye Kuang, 11 Jul 2024
Response to Reviewer #1
General comments:
This study used an advanced aerosol-fog sampling system to directly investigate the impacts of aerosol hygroscopic growth and activation processes on physical and chemical properties of submicron aerosols which is rarely done before. Presented results revealed significant shifts in aerosol size distributions and composition under both subsaturated and supersaturated high RH conditions, with more than 70% submicron aerosol migrated to supermicron ranges in foggy conditions, and over 25% of aerosol mass with dry diameters below 1 μm resided in supermicron ranges under subsaturated high RH (> 90%), shedding new insights into aerosol sampling and aerosol physical properties in foggy/cloudy and high RH conditions. Moreover, simultaneous measurements of aerosol chemical compositions shedding new insights into hygroscopic and activation properties of different aerosols types, which is important implications in both aerosol/cloud aqueous chemistry and cloud microphysics. In general, I think this manuscript is well organized and presented direct measurements of aerosol hygroscopic and activation processes with the view of aerosol size and chemistry which is very useful for aerosol and fog/cloud community，therefore suggest acceptance after minor revisions.
We thank the reviewer’s positive comments.
Minor comments:
Emphasize the broader implications of the research findings for aerosol/cloud science and atmospheric chemistry in the abstract
Corrected.
Following the reviewer’s comments, we added
“Overall, our study highlights remarkably different cloud and fog processing behaviors between primary and secondary aerosols, which would benefit a better understanding of aerosol-cloud interactions under distinct atmospheric conditions.”
Explicitly state the research objectives or questions towards the end of the introduction to guide readers on what to expect from the study. This helps to focus the reader's attention and provides a roadmap for the rest of the manuscript. Current version discussed too much on aerosol chemical compositions, however, discussions about current understandings of how aerosol hygroscopic growth and activation impacts on aerosol submicron aerosol compositions is relatively few.
We thank the reviewer’s comments. Indeed, we have expanded our discussion in the introduction to further explore how RH impacts aerosol chemical compositions, as only a limited number of studies have directly investigated the effects of aerosol hygroscopic growth and activation on aerosol size or chemical compositions.
To better clarify this point, the following sentences are added in the first paragraph:
“Most current studies primarily focus on the impact of RH on aerosol chemical compositions, with only a limited number of studies directly quantifying how aerosol hygroscopic growth and activation affect size and/or chemical compositions of aerosol”
-
RC2: 'Comment on egusphere-2024-998', Anonymous Referee #2, 21 May 2024
The comment was uploaded in the form of a supplement: https://egusphere.copernicus.org/preprints/2024/egusphere-2024-998/egusphere-2024-998-RC2-supplement.pdf
- AC2: 'Reply on RC2', Ye Kuang, 11 Jul 2024
Peer review completion
Journal article(s) based on this preprint
Viewed
| HTML | XML | Total | Supplement | BibTeX | EndNote | |
|---|---|---|---|---|---|---|
| 312 | 91 | 33 | 436 | 40 | 17 | 21 |
- HTML: 312
- PDF: 91
- XML: 33
- Total: 436
- Supplement: 40
- BibTeX: 17
- EndNote: 21
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1
Weiqi Xu
Wanyun Xu
Zhiqiang Zhang
Biao Luo
Xiaoyi Zhang
Jiangchuang Tao
Hongqin Qiao
Li Liu
The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.
- Preprint
(1072 KB) - Metadata XML
-
Supplement
(969 KB) - BibTeX
- EndNote
- Final revised paper