气候变化领域集成服务门户(CCPortal): Southern Ocean latitudinal gradients of cloud condensation nuclei

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DOI	10.5194/acp-21-12757-2021
	Southern Ocean latitudinal gradients of cloud condensation nuclei
	Humphries R.S.; Keywood M.D.; Gribben S.; McRobert I.M.; Ward J.P.; Selleck P.; Taylor S.; Harnwell J.; Flynn C.; Kulkarni G.R.; Mace G.G.; Protat A.; Alexander S.P.; McFarquhar G.
发表日期	2021
ISSN	1680-7316
起始页码	12757
结束页码	12782
卷号	21 期号:16
英文摘要	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, CN10) 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) CN10 and CCN0.5 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 CN10 and CCN0.5, respectively. In the southern sector, concentrations rose markedly, reaching 447 (298-446) cm-3 and 232 (186-271) cm-3 for CN10 and CCN0.5, 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 a substantially higher CCN0.5/CN10 activation ratio of 0.8 compared to around 0.4 for mid-latitudes. Long-term measurements at land-based research stations surrounding the Southern Ocean were found to be good representations at their respective latitudes; however this study highlighted the need for more long-term measurements in the region. CCN observations at Cape Grim (40 S) corresponded with CCN measurements from northern and mid-latitude sectors, while CN10 observations only corresponded with observations from the northern sector. Measurements from a simultaneous 2-year campaign at Macquarie Island (54 S) were found to represent all aerosol species well. The southernmost latitudes differed significantly from both of these stations, and previous work suggests that Antarctic stations on the East Antarctic coastline do not represent the East Antarctic sea-ice latitudes well. Further measurements are needed to capture the long-term, seasonal and longitudinal variability in aerosol processes across the Southern Ocean. © 2021 Ruhi S. Humphries et al.
语种	英语
scopus关键词	aerosol composition; atmospheric chemistry; cloud condensation nucleus; concentration (composition); latitudinal gradient; sea ice; Antarctica; Australia; Southern Ocean
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246627
作者单位	Climate Science Centre, CSIRO Oceans and Atmosphere, Melbourne, Australia; Australian Antarctic Program Partnership, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia; Engineering and Technology Program, CSIRO National Collections and Marine Infrastructure, Hobart, Australia; School of Meteorology, University of Oklahoma, Norman, United States; Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, United States; Department of Atmospheric Science, University of Utah, Salt Lake City, United States; Australian Bureau of Meteorology, Melbourne, Australia; Australian Antarctic Division, Channel Highway, Kingston, TAS 7050, Australia; Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, United States
推荐引用方式 GB/T 7714	Humphries R.S.,Keywood M.D.,Gribben S.,et al. Southern Ocean latitudinal gradients of cloud condensation nuclei[J],2021,21(16).
APA	Humphries R.S..,Keywood M.D..,Gribben S..,McRobert I.M..,Ward J.P..,...&McFarquhar G..(2021).Southern Ocean latitudinal gradients of cloud condensation nuclei.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(16).
MLA	Humphries R.S.,et al."Southern Ocean latitudinal gradients of cloud condensation nuclei".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.16(2021).