气候变化领域集成服务门户(CCPortal): Sea spray aerosol organic enrichment; water uptake and surface tension effects

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DOI	10.5194/acp-20-7955-2020
	Sea spray aerosol organic enrichment; water uptake and surface tension effects
	T. Cravigan L.; D. Mallet M.; Vaattovaara P.; J. Harvey M.; S. Law C.; L. Modini R.; M. Russell L.; Stelcer E.; D. Cohen D.; Olsen G.; Safi K.; J. Burrell T.; Ristovski Z.
发表日期	2020
ISSN	1680-7316
起始页码	7955
结束页码	7977
卷号	20 期号:13
英文摘要	The aerosol-driven radiative effects on marine low-level cloud represent a large uncertainty in climate simulations, in particular over the Southern Ocean, which is also an important region for sea spray aerosol production. Observations of sea spray aerosol organic enrichment and the resulting impact on water uptake over the remote Southern Hemisphere are scarce, and therefore the region is underrepresented in existing parameterisations. The Surface Ocean Aerosol Production (SOAP) voyage was a 23 d voyage which sampled three phytoplankton blooms in the highly productive water of the Chatham Rise, east of New Zealand. In this study we examined the enrichment of organics to nascent sea spray aerosol and the modifications to sea spray aerosol water uptake using in situ chamber measurements of seawater samples taken during the SOAP voyage. Primary marine organics contributed up to 23% of the sea spray mass for particles with diameter less than approximately 1 m and up to 79% of the particle volume for 50 nm diameter sea spray. The composition of the submicron organic fraction was consistent throughout the voyage and was largely composed of a polysaccharide-like component, characterised by very low alkane-to-hydroxylconcentration ratios of approximately 0.1 0.2. The enrichment of organics was compared to the output from the chlorophyll-a-based sea spray aerosol parameterisation suggested by Gantt et al. (2011) and the OCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) models. OCEANFILMS improved on the representation of the organic fraction predicted using chlorophyll a, in particular when the co-adsorption of polysaccharides was included; however, the model still under-predicted the proportion of polysaccharides by an average of 33 %. Nascent 50 nm diameter sea spray aerosol hygroscopic growth factors measured at 90% relative humidity averaged 1:930:08 and did not decrease with increasing sea spray aerosol organic fractions. The observed hygroscopicity was greater than expected from the assumption of full solubility, particularly during the most productive phytoplankton bloom (B1), during which organic fractions were greater than approximately 0.4. The water uptake behaviour observed in this study is consistent with that observed for other measurements of phytoplankton blooms and can be partially attributed to the presence of sea salt hydrates, which lowers the sea spray aerosol hygroscopicity when the organic enrichment is low. The inclusion of surface tension effects only marginally improved the modelled hygroscopicity, and a significant discrepancy between the observed and modelled hygroscopicity at high organic volume fractions remained. The findings from the SOAP voyage highlight the influence of biologically sourced organics on sea spray aerosol composition; these data improve the capacity to parameterise sea spray aerosol organic enrichment and water uptake. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	aerosol composition; algal bloom; chlorophyll a; enrichment; hygroscopicity; parameterization; polysaccharide; spray; surface tension; water uptake; Chatham Rise; Pacific Ocean; 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/141228
作者单位	School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia; Department of Environmental Science, University of Eastern Finland, Kuopio, Finland; National Institute of Water and Atmospheric Research, Wellington, New Zealand; Department of Marine Sciences, University of Otago, Dunedin, New Zealand; Scripps Institute of Oceanography, University of California, San Diego, CA, United States; Centre for Accelerator Science, Nstli, Australian Nuclear Science and Technology Organisation, Menai, NSW, Australia; National Institute of Water and Atmospheric Research, Hamilton, New Zealand; Australian Antarctic Program Partnership, Institute for Marine and Antarctic Science, University of Tasmania, Hobart, Australia; Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen PSI, 5232, Switzerland
推荐引用方式 GB/T 7714	T. Cravigan L.,D. Mallet M.,Vaattovaara P.,et al. Sea spray aerosol organic enrichment; water uptake and surface tension effects[J],2020,20(13).
APA	T. Cravigan L..,D. Mallet M..,Vaattovaara P..,J. Harvey M..,S. Law C..,...&Ristovski Z..(2020).Sea spray aerosol organic enrichment; water uptake and surface tension effects.Atmospheric Chemistry and Physics,20(13).
MLA	T. Cravigan L.,et al."Sea spray aerosol organic enrichment; water uptake and surface tension effects".Atmospheric Chemistry and Physics 20.13(2020).