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DOI	10.5194/acp-19-6419-2019
	Sensitivity of Arctic sulfate aerosol and clouds to changes in future surface seawater dimethylsulfide concentrations
	Mahmood R.; Von Salzen K.; Norman A.-L.; Galí M.; Levasseur M.
发表日期	2019
ISSN	16807316
起始页码	6419
结束页码	6435
卷号	19 期号:9
英文摘要	Dimethylsulfide (DMS), outgassed from ocean waters, plays an important role in the climate system, as it oxidizes to methane sulfonic acid (MSA) and sulfur dioxide (SO2), which can lead to the formation of sulfate aerosol. Newly formed sulfate aerosol resulting from DMS oxidation may grow by condensation of gases, in-cloud oxidation, and coagulation to sizes where they may act as cloud condensation nuclei (CCN) and influence cloud properties. Under future global warming conditions, sea ice in the Arctic region is expected to decline significantly, which may lead to increased emissions of DMS from the open ocean and changes in cloud regimes. In this study we evaluate impacts of DMS on Arctic sulfate aerosol budget, changes in cloud droplet number concentration (CDNC), and cloud radiative forcing in the Arctic region under current and future sea ice conditions using an atmospheric global climate model. Given that future DMS concentrations are highly uncertain, several simulations with different surface seawater DMS concentrations and spatial distributions in the Arctic were performed in order to determine the sensitivity of sulfate aerosol budgets, CDNC, and cloud radiative forcing to Arctic surface seawater DMS concentrations. For any given amount and distribution of Arctic surface seawater DMS, similar amounts of sulfate are produced by oxidation of DMS in 2000 and 2050 despite large increases in DMS emission in the latter period due to sea ice retreat in the simulations. This relatively low sensitivity of sulfate burden is related to enhanced sulfate wet removal by precipitation in 2050. However simulated aerosol nucleation rates are higher in 2050, which results in an overall increase in CDNC and substantially more negative cloud radiative forcing. Thus potential future reductions in sea ice extent may cause cloud albedos to increase, resulting in a negative climate feedback on radiative forcing in the Arctic associated with ocean DMS emissions. © Author(s) 2019.
语种	英语
scopus关键词	aerosol; climate feedback; cloud cover; concentration (composition); condensation; dimethylsulfide; global warming; ice retreat; radiative forcing; sea ice; seawater; sensitivity analysis; sulfate; Arctic
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/144408
作者单位	School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, Canada; Canadian Center for Climate Modelling and Analysis, Environment and Climate Change Canada, Victoria, BC, Canada; Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Takuvik Joint International Laboratory and Québec-Océan, Université Laval, Québec, QC, Canada; Département de Biologie and Québec-Océan, Université Laval, Québec, QC, Canada; Climate Prediction Group, Barcelona Supercomputing Center, Barcelona, Spain
推荐引用方式 GB/T 7714	Mahmood R.,Von Salzen K.,Norman A.-L.,et al. Sensitivity of Arctic sulfate aerosol and clouds to changes in future surface seawater dimethylsulfide concentrations[J],2019,19(9).
APA	Mahmood R.,Von Salzen K.,Norman A.-L.,Galí M.,&Levasseur M..(2019).Sensitivity of Arctic sulfate aerosol and clouds to changes in future surface seawater dimethylsulfide concentrations.Atmospheric Chemistry and Physics,19(9).
MLA	Mahmood R.,et al."Sensitivity of Arctic sulfate aerosol and clouds to changes in future surface seawater dimethylsulfide concentrations".Atmospheric Chemistry and Physics 19.9(2019).