Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols
Cloud-radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations, and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial...
Published in: | Atmospheric Chemistry and Physics |
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Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
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European Geosciences Union
2020
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Online Access: | https://eprints.qut.edu.au/202180/ |
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Queensland University of Technology: QUT ePrints |
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Cloud-radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations, and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial stations or a limited set of instrumentation and often present findings as broad seasonal or latitudinal trends. Here, we present an extensive set of aerosol and meteorological observations obtained during an austral summer cruise across the full width of the Southern Ocean south of Australia. Three episodes of continental-influenced air masses were identified, including an apparent transition between the Ferrel atmospheric cell and the polar cell at approximately 64span classCombining double low line"inline-formula" S, and accompanied by the highest median cloud condensation nuclei (CCN) concentrations, at 252 cmspan classCombining double low line"inline-formula"-3. During the other two episodes, synoptic-scale weather patterns diverted air masses across distances greater than 1000 km from the Australian and Antarctic coastlines, respectively, indicating that a large proportion of the Southern Ocean may be periodically influenced by continental air masses. In all three cases, a highly cloud-active accumulation mode dominated the size distribution, with up to 93 % of the total number concentration activating as CCN. Frequent cyclonic weather conditions were observed at high latitudes and the associated strong wind speeds led to predictions of high concentrations of sea spray aerosol. However, these modelled concentrations were not achieved due to increased aerosol scavenging rates from precipitation and convective transport into the free troposphere, which decoupled the air mass from the sea spray flux at the ocean surface. CCN concentrations were more strongly impacted by high concentrations of large-diameter Aitken mode aerosol in air masses which passed over regions of elevated marine biological productivity, ... |
format |
Article in Journal/Newspaper |
author |
Alroe, Joel Cravigan, Luke Miljevic, Branka Johnson, Graham Selleck, Paul W. Humphries, Ruhi Keywood, Melita Doris Chambers, Scott D. Williams, Alastair Ristovski, Zoran |
spellingShingle |
Alroe, Joel Cravigan, Luke Miljevic, Branka Johnson, Graham Selleck, Paul W. Humphries, Ruhi Keywood, Melita Doris Chambers, Scott D. Williams, Alastair Ristovski, Zoran Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
author_facet |
Alroe, Joel Cravigan, Luke Miljevic, Branka Johnson, Graham Selleck, Paul W. Humphries, Ruhi Keywood, Melita Doris Chambers, Scott D. Williams, Alastair Ristovski, Zoran |
author_sort |
Alroe, Joel |
title |
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
title_short |
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
title_full |
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
title_fullStr |
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
title_full_unstemmed |
Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols |
title_sort |
marine productivity and synoptic meteorology drive summer-time variability in southern ocean aerosols |
publisher |
European Geosciences Union |
publishDate |
2020 |
url |
https://eprints.qut.edu.au/202180/ |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Atmospheric Chemistry and Physics |
op_relation |
https://eprints.qut.edu.au/202180/1/63566732.pdf doi:10.5194/acp-20-8047-2020 Alroe, Joel, Cravigan, Luke, Miljevic, Branka, Johnson, Graham, Selleck, Paul W., Humphries, Ruhi, Keywood, Melita Doris, Chambers, Scott D., Williams, Alastair, & Ristovski, Zoran (2020) Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols. Atmospheric Chemistry and Physics, 20(13), pp. 8047-8062. https://eprints.qut.edu.au/202180/ Centre for the Environment; Institute for Future Environments; Science & Engineering Faculty; Faculty of Science; School of Earth & Atmospheric Sciences; Centre for Tropical Crops and Biocommodities |
op_rights |
free_to_read http://creativecommons.org/licenses/by/4.0/ The Author(s) This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the document is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recognise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to qut.copyright@qut.edu.au |
op_doi |
https://doi.org/10.5194/acp-20-8047-2020 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
20 |
container_issue |
13 |
container_start_page |
8047 |
op_container_end_page |
8062 |
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1797572741844434944 |
spelling |
ftqueensland:oai:eprints.qut.edu.au:202180 2024-04-28T08:00:35+00:00 Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols Alroe, Joel Cravigan, Luke Miljevic, Branka Johnson, Graham Selleck, Paul W. Humphries, Ruhi Keywood, Melita Doris Chambers, Scott D. Williams, Alastair Ristovski, Zoran 2020-07-10 application/pdf https://eprints.qut.edu.au/202180/ unknown European Geosciences Union https://eprints.qut.edu.au/202180/1/63566732.pdf doi:10.5194/acp-20-8047-2020 Alroe, Joel, Cravigan, Luke, Miljevic, Branka, Johnson, Graham, Selleck, Paul W., Humphries, Ruhi, Keywood, Melita Doris, Chambers, Scott D., Williams, Alastair, & Ristovski, Zoran (2020) Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols. Atmospheric Chemistry and Physics, 20(13), pp. 8047-8062. https://eprints.qut.edu.au/202180/ Centre for the Environment; Institute for Future Environments; Science & Engineering Faculty; Faculty of Science; School of Earth & Atmospheric Sciences; Centre for Tropical Crops and Biocommodities free_to_read http://creativecommons.org/licenses/by/4.0/ The Author(s) This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the document is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recognise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to qut.copyright@qut.edu.au Atmospheric Chemistry and Physics Contribution to Journal 2020 ftqueensland https://doi.org/10.5194/acp-20-8047-2020 2024-04-10T00:05:58Z Cloud-radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations, and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial stations or a limited set of instrumentation and often present findings as broad seasonal or latitudinal trends. Here, we present an extensive set of aerosol and meteorological observations obtained during an austral summer cruise across the full width of the Southern Ocean south of Australia. Three episodes of continental-influenced air masses were identified, including an apparent transition between the Ferrel atmospheric cell and the polar cell at approximately 64span classCombining double low line"inline-formula" S, and accompanied by the highest median cloud condensation nuclei (CCN) concentrations, at 252 cmspan classCombining double low line"inline-formula"-3. During the other two episodes, synoptic-scale weather patterns diverted air masses across distances greater than 1000 km from the Australian and Antarctic coastlines, respectively, indicating that a large proportion of the Southern Ocean may be periodically influenced by continental air masses. In all three cases, a highly cloud-active accumulation mode dominated the size distribution, with up to 93 % of the total number concentration activating as CCN. Frequent cyclonic weather conditions were observed at high latitudes and the associated strong wind speeds led to predictions of high concentrations of sea spray aerosol. However, these modelled concentrations were not achieved due to increased aerosol scavenging rates from precipitation and convective transport into the free troposphere, which decoupled the air mass from the sea spray flux at the ocean surface. CCN concentrations were more strongly impacted by high concentrations of large-diameter Aitken mode aerosol in air masses which passed over regions of elevated marine biological productivity, ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Queensland University of Technology: QUT ePrints Atmospheric Chemistry and Physics 20 13 8047 8062 |