Cloud condensation nuclei closure study on summer arctic aerosol
We present an aerosol – cloud condensation nuclei (CCN) closure study on summer high Arctic aerosol based on measurements that were carried out in 2008 during the Arctic Summer Cloud Ocean Study (ASCOS) on board the Swedish ice breaker Oden . The data presented here were collected during a three-wee...
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ftcopernicus:oai:publications.copernicus.org:acp10604 2023-05-15T14:55:21+02:00 Cloud condensation nuclei closure study on summer arctic aerosol Martin, M. Chang, R. Y.-W. Sierau, B. Sjogren, S. Swietlicki, E. Abbatt, J. P. D. Leck, C. Lohmann, U. 2018-01-15 application/pdf https://doi.org/10.5194/acp-11-11335-2011 https://www.atmos-chem-phys.net/11/11335/2011/ eng eng doi:10.5194/acp-11-11335-2011 https://www.atmos-chem-phys.net/11/11335/2011/ eISSN: 1680-7324 Text 2018 ftcopernicus https://doi.org/10.5194/acp-11-11335-2011 2019-12-24T09:56:34Z We present an aerosol – cloud condensation nuclei (CCN) closure study on summer high Arctic aerosol based on measurements that were carried out in 2008 during the Arctic Summer Cloud Ocean Study (ASCOS) on board the Swedish ice breaker Oden . The data presented here were collected during a three-week time period in the pack ice (>85° N) when the icebreaker Oden was moored to an ice floe and drifted passively during the most biological active period into autumn freeze up conditions. CCN number concentrations were obtained using two CCN counters measuring at different supersaturations. The directly measured CCN number concentration was then compared with a CCN number concentration calculated using both bulk aerosol mass composition data from an aerosol mass spectrometer (AMS) and aerosol number size distributions obtained from a differential mobility particle sizer, assuming κ-Köhler theory, surface tension of water and an internally mixed aerosol. The last assumption was supported by measurements made with a hygroscopic tandem differential mobility analyzer (HTDMA) for particles >70 nm. For the two highest measured supersaturations, 0.73 and 0.41%, closure could not be achieved with the investigated settings concerning hygroscopicity and density. The calculated CCN number concentration was always higher than the measured one for those two supersaturations. This might be caused by a relative larger insoluble organic mass fraction of the smaller particles that activate at these supersaturations, which are thus less good CCN than the larger particles. On average, 36% of the mass measured with the AMS was organic mass. At 0.20, 0.15 and 0.10% supersaturation, closure could be achieved with different combinations of hygroscopic parameters and densities within the uncertainty range of the fit. The best agreement of the calculated CCN number concentration with the observed one was achieved when the organic fraction of the aerosol was treated as nearly water insoluble (κ org =0.02), leading to a mean total κ, κ tot , of 0.33 ± 0.13. However, several settings led to closure and κ org =0.2 is found to be an upper limit at 0.1% supersaturation. κ org ≤0.2 leads to a κ tot range of 0.33 ± 013 to 0.50 ± 0.11. Thus, the organic material ranges from being sparingly soluble to effectively insoluble. These results suggest that an increase in organic mass fraction in particles of a certain size would lead to a suppression of the Arctic CCN activity. Text Arctic oden Copernicus Publications: E-Journals Arctic Breaker ENVELOPE(-67.257,-67.257,-67.874,-67.874) Atmospheric Chemistry and Physics 11 22 11335 11350 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
We present an aerosol – cloud condensation nuclei (CCN) closure study on summer high Arctic aerosol based on measurements that were carried out in 2008 during the Arctic Summer Cloud Ocean Study (ASCOS) on board the Swedish ice breaker Oden . The data presented here were collected during a three-week time period in the pack ice (>85° N) when the icebreaker Oden was moored to an ice floe and drifted passively during the most biological active period into autumn freeze up conditions. CCN number concentrations were obtained using two CCN counters measuring at different supersaturations. The directly measured CCN number concentration was then compared with a CCN number concentration calculated using both bulk aerosol mass composition data from an aerosol mass spectrometer (AMS) and aerosol number size distributions obtained from a differential mobility particle sizer, assuming κ-Köhler theory, surface tension of water and an internally mixed aerosol. The last assumption was supported by measurements made with a hygroscopic tandem differential mobility analyzer (HTDMA) for particles >70 nm. For the two highest measured supersaturations, 0.73 and 0.41%, closure could not be achieved with the investigated settings concerning hygroscopicity and density. The calculated CCN number concentration was always higher than the measured one for those two supersaturations. This might be caused by a relative larger insoluble organic mass fraction of the smaller particles that activate at these supersaturations, which are thus less good CCN than the larger particles. On average, 36% of the mass measured with the AMS was organic mass. At 0.20, 0.15 and 0.10% supersaturation, closure could be achieved with different combinations of hygroscopic parameters and densities within the uncertainty range of the fit. The best agreement of the calculated CCN number concentration with the observed one was achieved when the organic fraction of the aerosol was treated as nearly water insoluble (κ org =0.02), leading to a mean total κ, κ tot , of 0.33 ± 0.13. However, several settings led to closure and κ org =0.2 is found to be an upper limit at 0.1% supersaturation. κ org ≤0.2 leads to a κ tot range of 0.33 ± 013 to 0.50 ± 0.11. Thus, the organic material ranges from being sparingly soluble to effectively insoluble. These results suggest that an increase in organic mass fraction in particles of a certain size would lead to a suppression of the Arctic CCN activity. |
format |
Text |
author |
Martin, M. Chang, R. Y.-W. Sierau, B. Sjogren, S. Swietlicki, E. Abbatt, J. P. D. Leck, C. Lohmann, U. |
spellingShingle |
Martin, M. Chang, R. Y.-W. Sierau, B. Sjogren, S. Swietlicki, E. Abbatt, J. P. D. Leck, C. Lohmann, U. Cloud condensation nuclei closure study on summer arctic aerosol |
author_facet |
Martin, M. Chang, R. Y.-W. Sierau, B. Sjogren, S. Swietlicki, E. Abbatt, J. P. D. Leck, C. Lohmann, U. |
author_sort |
Martin, M. |
title |
Cloud condensation nuclei closure study on summer arctic aerosol |
title_short |
Cloud condensation nuclei closure study on summer arctic aerosol |
title_full |
Cloud condensation nuclei closure study on summer arctic aerosol |
title_fullStr |
Cloud condensation nuclei closure study on summer arctic aerosol |
title_full_unstemmed |
Cloud condensation nuclei closure study on summer arctic aerosol |
title_sort |
cloud condensation nuclei closure study on summer arctic aerosol |
publishDate |
2018 |
url |
https://doi.org/10.5194/acp-11-11335-2011 https://www.atmos-chem-phys.net/11/11335/2011/ |
long_lat |
ENVELOPE(-67.257,-67.257,-67.874,-67.874) |
geographic |
Arctic Breaker |
geographic_facet |
Arctic Breaker |
genre |
Arctic oden |
genre_facet |
Arctic oden |
op_source |
eISSN: 1680-7324 |
op_relation |
doi:10.5194/acp-11-11335-2011 https://www.atmos-chem-phys.net/11/11335/2011/ |
op_doi |
https://doi.org/10.5194/acp-11-11335-2011 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
11 |
container_issue |
22 |
container_start_page |
11335 |
op_container_end_page |
11350 |
_version_ |
1766327155127484416 |