气候变化领域集成服务门户(CCPortal): The Role of Cloud Processing for the Ice Nucleating Ability of Organic Aerosol and Coal Fly Ash Particles

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DOI	10.1029/2020JD033338
	The Role of Cloud Processing for the Ice Nucleating Ability of Organic Aerosol and Coal Fly Ash Particles
	Kilchhofer K.; Mahrt F.; Kanji Z.A.
发表日期	2021
ISSN	2169897X
卷号	126 期号:10
英文摘要	Ice nucleating particles are a minor fraction of tropospheric aerosol, yet they play a key role for cloud microphysical processes. One poorly understood process is the impact of atmospheric aging of aerosol particles on ice nucleation. Here we study the impact of cloud processing on the ice nucleation abilities of two physicochemically different aerosol particles by taking two model systems for atmospheric organic aerosol (OA), as well as coal fly ash (CFA) particles representing an inorganic aerosol type. The ice nucleation activity of the unprocessed particles is compared to aerosol particles that are first exposed to conditions mimicking trajectories though cirrus clouds (CC) and mixed-phase clouds (MPC) prior to testing their ice nucleation activity at temperatures below 243 K. We observed that unprocessed OA do not exhibit heterogeneous ice nucleation, requiring homogeneous freezing conditions of solution droplets to form ice. However, after CC processing raffinose particles showed heterogeneous ice nucleation activity at 218 K and a water saturation ratio of 0.68–0.82, reaching activated fractions of up to 0.3. This enhancement compared to unprocessed raffinose particles results from an increase in particle viscosity upon CC processing. We also present new results of unprocessed CFA particles exhibiting strong heterogeneous ice nucleation activity at temperatures below 235 K in the deposition and/or pore condensation and freezing mode. In contrast to the OA, the CFA show a decrease in ice nucleation activity after both MPC and CC processing. Furthermore, cloud processing and generating CFA particles from aqueous suspensions do not have the same effect on their ice nucleation ability. © 2021. The Authors.
英文关键词	cloud processing; coal fly ash; ice nucleation; organic aerosol; viscous glassy aerosol, aging, phase state
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/185200
作者单位	Department of Environmental System Science, Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland; Now at: Laboratory of Environmental Chemistry, Paul Scherrer Institute, Villigen, Switzerland; Now at: Department of Chemistry, University of British Columbia, Vancouver, Canada
推荐引用方式 GB/T 7714	Kilchhofer K.,Mahrt F.,Kanji Z.A.. The Role of Cloud Processing for the Ice Nucleating Ability of Organic Aerosol and Coal Fly Ash Particles[J],2021,126(10).
APA	Kilchhofer K.,Mahrt F.,&Kanji Z.A..(2021).The Role of Cloud Processing for the Ice Nucleating Ability of Organic Aerosol and Coal Fly Ash Particles.Journal of Geophysical Research: Atmospheres,126(10).
MLA	Kilchhofer K.,et al."The Role of Cloud Processing for the Ice Nucleating Ability of Organic Aerosol and Coal Fly Ash Particles".Journal of Geophysical Research: Atmospheres 126.10(2021).