Southern Ocean latitudinal gradients of cloud condensation nuclei
The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system mode...
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Online Access: | http://www.osti.gov/servlets/purl/1819681 https://www.osti.gov/biblio/1819681 https://doi.org/10.5194/acp-21-12757-2021 |
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ftosti:oai:osti.gov:1819681 2023-07-30T03:59:21+02:00 Southern Ocean latitudinal gradients of cloud condensation nuclei Humphries, Ruhi S. Keywood, Melita D. Gribben, Sean McRobert, Ian M. Ward, Jason P. Selleck, Paul Taylor, Sally Harnwell, James Flynn, Connor Kulkarni, Gourihar R. Mace, Gerald G. Protat, Alain Alexander, Simon P. McFarquhar, Greg 2021-09-16 application/pdf http://www.osti.gov/servlets/purl/1819681 https://www.osti.gov/biblio/1819681 https://doi.org/10.5194/acp-21-12757-2021 unknown http://www.osti.gov/servlets/purl/1819681 https://www.osti.gov/biblio/1819681 https://doi.org/10.5194/acp-21-12757-2021 doi:10.5194/acp-21-12757-2021 54 ENVIRONMENTAL SCIENCES 2021 ftosti https://doi.org/10.5194/acp-21-12757-2021 2023-07-11T10:06:53Z The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system models. While remoteness from anthropogenic and continental sources is responsible for its clean atmosphere, this also results in the dearth of atmospheric observations in the region. Here we present a statistical summary of the latitudinal gradient of aerosol (condensation nuclei larger than 10 nm, CN 10 ) and cloud condensation nuclei (CCN at various supersaturations) concentrations obtained from five voyages spanning the Southern Ocean between Australia and Antarctica from late spring to early autumn (October to March) of the 2017/18 austral seasons. Three main regions of influence were identified: the northern sector (40–45° S), where continental and anthropogenic sources coexisted with background marine aerosol populations; the mid-latitude sector (45–65° S), where the aerosol populations reflected a mixture of biogenic and sea-salt aerosol; and the southern sector (65–70° S), south of the atmospheric polar front, where sea-salt aerosol concentrations were greatly reduced and aerosol populations were primarily biologically derived sulfur species with a significant history in the Antarctic free troposphere. The northern sector showed the highest number concentrations with median (25th to 75th percentiles) CN 10 and CCN 0.5 concentrations of 681 (388–839) cm –3 and 322 (105–443) cm –3 , respectively. Concentrations in the mid-latitudes were typically around 350 cm –3 and 160 cm –3 for CN 10 and CCN 0.5 , respectively. In the southern sector, concentrations rose markedly, reaching 447 (298–446) cm –3 and 232 (186–271) cm –3 for CN 10 and CCN 0.5 , respectively. The aerosol composition in this sector was marked by a distinct drop in sea salt and increase in both sulfate fraction and absolute concentrations, resulting in ... Other/Unknown Material Antarc* Antarctic Antarctica Southern Ocean SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Antarctic Southern Ocean The Antarctic Austral Atmospheric Chemistry and Physics 21 16 12757 12782 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
spellingShingle |
54 ENVIRONMENTAL SCIENCES Humphries, Ruhi S. Keywood, Melita D. Gribben, Sean McRobert, Ian M. Ward, Jason P. Selleck, Paul Taylor, Sally Harnwell, James Flynn, Connor Kulkarni, Gourihar R. Mace, Gerald G. Protat, Alain Alexander, Simon P. McFarquhar, Greg Southern Ocean latitudinal gradients of cloud condensation nuclei |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
The Southern Ocean region is one of the most pristine in the world and serves as an important proxy for the pre-industrial atmosphere. Improving our understanding of the natural processes in this region is likely to result in the largest reductions in the uncertainty of climate and earth system models. While remoteness from anthropogenic and continental sources is responsible for its clean atmosphere, this also results in the dearth of atmospheric observations in the region. Here we present a statistical summary of the latitudinal gradient of aerosol (condensation nuclei larger than 10 nm, CN 10 ) and cloud condensation nuclei (CCN at various supersaturations) concentrations obtained from five voyages spanning the Southern Ocean between Australia and Antarctica from late spring to early autumn (October to March) of the 2017/18 austral seasons. Three main regions of influence were identified: the northern sector (40–45° S), where continental and anthropogenic sources coexisted with background marine aerosol populations; the mid-latitude sector (45–65° S), where the aerosol populations reflected a mixture of biogenic and sea-salt aerosol; and the southern sector (65–70° S), south of the atmospheric polar front, where sea-salt aerosol concentrations were greatly reduced and aerosol populations were primarily biologically derived sulfur species with a significant history in the Antarctic free troposphere. The northern sector showed the highest number concentrations with median (25th to 75th percentiles) CN 10 and CCN 0.5 concentrations of 681 (388–839) cm –3 and 322 (105–443) cm –3 , respectively. Concentrations in the mid-latitudes were typically around 350 cm –3 and 160 cm –3 for CN 10 and CCN 0.5 , respectively. In the southern sector, concentrations rose markedly, reaching 447 (298–446) cm –3 and 232 (186–271) cm –3 for CN 10 and CCN 0.5 , respectively. The aerosol composition in this sector was marked by a distinct drop in sea salt and increase in both sulfate fraction and absolute concentrations, resulting in ... |
author |
Humphries, Ruhi S. Keywood, Melita D. Gribben, Sean McRobert, Ian M. Ward, Jason P. Selleck, Paul Taylor, Sally Harnwell, James Flynn, Connor Kulkarni, Gourihar R. Mace, Gerald G. Protat, Alain Alexander, Simon P. McFarquhar, Greg |
author_facet |
Humphries, Ruhi S. Keywood, Melita D. Gribben, Sean McRobert, Ian M. Ward, Jason P. Selleck, Paul Taylor, Sally Harnwell, James Flynn, Connor Kulkarni, Gourihar R. Mace, Gerald G. Protat, Alain Alexander, Simon P. McFarquhar, Greg |
author_sort |
Humphries, Ruhi S. |
title |
Southern Ocean latitudinal gradients of cloud condensation nuclei |
title_short |
Southern Ocean latitudinal gradients of cloud condensation nuclei |
title_full |
Southern Ocean latitudinal gradients of cloud condensation nuclei |
title_fullStr |
Southern Ocean latitudinal gradients of cloud condensation nuclei |
title_full_unstemmed |
Southern Ocean latitudinal gradients of cloud condensation nuclei |
title_sort |
southern ocean latitudinal gradients of cloud condensation nuclei |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1819681 https://www.osti.gov/biblio/1819681 https://doi.org/10.5194/acp-21-12757-2021 |
geographic |
Antarctic Southern Ocean The Antarctic Austral |
geographic_facet |
Antarctic Southern Ocean The Antarctic Austral |
genre |
Antarc* Antarctic Antarctica Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Southern Ocean |
op_relation |
http://www.osti.gov/servlets/purl/1819681 https://www.osti.gov/biblio/1819681 https://doi.org/10.5194/acp-21-12757-2021 doi:10.5194/acp-21-12757-2021 |
op_doi |
https://doi.org/10.5194/acp-21-12757-2021 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
21 |
container_issue |
16 |
container_start_page |
12757 |
op_container_end_page |
12782 |
_version_ |
1772810125804830720 |