气候变化领域集成服务门户(CCPortal): The Urmia playa as a source of airborne dust and ice-nucleating particles - Part 2: Unraveling the relationship between soil dust composition and ice nucleation activity

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DOI	10.5194/acp-22-14931-2022
	The Urmia playa as a source of airborne dust and ice-nucleating particles - Part 2: Unraveling the relationship between soil dust composition and ice nucleation activity
	Hamzehpour, Nikou; Marcolli, Claudia; Klumpp, Kristian; Thony, Debora; Peter, Thomas
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	14931
结束页码	14956
卷号	22 期号:22 页码:26
英文摘要	Ice-nucleating particles (INPs) originating from deserts, semi-arid regions, and dried lakebeds may cause heterogeneous ice nucleation, impacting cloud properties. Recently, due to climate change and water scarcity, abandoned agricultural lands with little surficial crust and negligible vegetation cover have become an increasing source of atmospheric dust worldwide. Unlike deserts, these areas are rich in soluble salt and (bio-)organic compounds. Using soil samples from various sites of the Lake Urmia playa (LUP) in northwestern Iran and airborne dusts collected at nearby meteorological stations, we elucidate how minerals, soluble salts, and organic matter interact to determine the IN activity of saline soils and dust. X-ray powder diffraction shows that the mineralogical composition is dominated by K-feldspars (microcline), quartz, carbonates, and clay minerals. The samples were stripped stepwise of organic matter, carbonates, and soluble salts. After each removal step, the ice nucleation (IN) activity was quantified in terms of onset freezing temperatures (T-het) and heterogeneously frozen fractions (F-het) by emulsion freezing experiments using differential scanning calorimetry (DSC). We examined the influence of soluble salts and pH on microcline and quartz in emulsion freezing experiments, comparing these with reference suspensions of microcline and quartz exposed to salt concentrations and pH levels characteristic of the LUP samples. These analyses, combined with correlations between T-het and F-het, allow us to identify the components that contribute to or inhibit IN activity. The LUP dusts turn out to be very good INPs, with freezing onset temperatures around 248 K in immersion freezing experiments. Interestingly, their IN activity proves to be dominated by the relatively small share of (bio-)organic matter (1 %-5.3 %). After organic matter removal, the remaining IN activity (T-het asymptotic to 244 K) can be traced back to the clay fraction, because T-het and F-het correlate positively with the clay mineral content but negatively with quartz and microcline. We attribute the inability of quartz and microcline to act as INPs to the basic pH of the LUP samples as well as to the presence of soluble salts. After additionally removing soluble salts and carbonates, the IN activity of the samples increased again significantly (T-het asymptotic to 249 K), and the negative correlation with quartz and microcline turned into a slightly positive one. Removing carbonates and salts from the natural samples leads to an increase in T-het and F-het as well, indicating that their presence also suppresses the IN activity of the (bio-)organic INPs. Overall, this study demonstrates that mineral and organic INPs do not just add up to yield the IN activity of soil dust but that the freezing behavior is governed by inhibiting and promoting interactions between the components.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000889112900001
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/273322
作者单位	University of Maragheh; Swiss Federal Institutes of Technology Domain; ETH Zurich; Swiss Federal Institutes of Technology Domain; ETH Zurich
推荐引用方式 GB/T 7714	Hamzehpour, Nikou,Marcolli, Claudia,Klumpp, Kristian,et al. The Urmia playa as a source of airborne dust and ice-nucleating particles - Part 2: Unraveling the relationship between soil dust composition and ice nucleation activity[J],2022,22(22):26.
APA	Hamzehpour, Nikou,Marcolli, Claudia,Klumpp, Kristian,Thony, Debora,&Peter, Thomas.(2022).The Urmia playa as a source of airborne dust and ice-nucleating particles - Part 2: Unraveling the relationship between soil dust composition and ice nucleation activity.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(22),26.
MLA	Hamzehpour, Nikou,et al."The Urmia playa as a source of airborne dust and ice-nucleating particles - Part 2: Unraveling the relationship between soil dust composition and ice nucleation activity".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.22(2022):26.