气候变化领域集成服务门户(CCPortal): Pore condensation and freezing is responsible for ice formation below water saturation for porous particles

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DOI	10.1073/pnas.1813647116
	Pore condensation and freezing is responsible for ice formation below water saturation for porous particles
	David R.O.; Marcolli C.; Fahrni J.; Qiu Y.; Perez Sirkin Y.A.; Molinero V.; Mahrt F.; Brühwiler D.; Lohmann U.; Kanji Z.A.
发表日期	2019
ISSN	0027-8424
起始页码	8184
结束页码	8189
卷号	116 期号:17
英文摘要	Ice nucleation in the atmosphere influences cloud properties, altering precipitation and the radiative balance, ultimately regulating Earth’s climate. An accepted ice nucleation pathway, known as deposition nucleation, assumes a direct transition of water from the vapor to the ice phase, without an intermediate liquid phase. However, studies have shown that nucleation occurs through a liquid phase in porous particles with narrow cracks or surface imperfections where the condensation of liquid below water saturation can occur, questioning the validity of deposition nucleation. We show that deposition nucleation cannot explain the strongly enhanced ice nucleation efficiency of porous compared with nonporous particles at temperatures below −40 °C and the absence of ice nucleation below water saturation at −35 °C. Using classical nucleation theory (CNT) and molecular dynamics simulations (MDS), we show that a network of closely spaced pores is necessary to overcome the barrier for macroscopic ice-crystal growth from narrow cylindrical pores. In the absence of pores, CNT predicts that the nucleation barrier is insurmountable, consistent with the absence of ice formation in MDS. Our results confirm that pore condensation and freezing (PCF), i.e., a mechanism of ice formation that proceeds via liquid water condensation in pores, is a dominant pathway for atmospheric ice nucleation below water saturation. We conclude that the ice nucleation activity of particles in the cirrus regime is determined by the porosity and wettability of pores. PCF represents a mechanism by which porous particles like dust could impact cloud radiative forcing and, thus, the climate via ice cloud formation. © 2019 National Academy of Sciences. All rights reserved.
英文关键词	Cirrus; Clouds; Deposition nucleation; Ice nucleation; Pore condensation and freezing
语种	英语
scopus关键词	ice; Article; chemical reaction; crystallization; low temperature procedures; molecular dynamics; pore condensation; pore size distribution; porosity; priority journal; synthesis; water metabolism; water saturation; water transport; wettability
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160417
作者单位	David, R.O., Department of Environmental Systems Science, Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, 8092, Switzerland; Marcolli, C., Department of Environmental Systems Science, Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, 8092, Switzerland; Fahrni, J., Institute of Chemistry and Biotechnology, Zurich University of Applied Sciences (ZHAW), Wädenswil, 8820, Switzerland; Qiu, Y., Department of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, United States; Perez Sirkin, Y.A., Department of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, United States; Molinero, V., Department of Chemistry, University of Utah, Salt Lake City, UT 84112-0850, United States; Mahrt, F., Department of Environmental Systems Science, Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, 8092, Switzerland; Brühwiler, D., Insti...
推荐引用方式 GB/T 7714	David R.O.,Marcolli C.,Fahrni J.,et al. Pore condensation and freezing is responsible for ice formation below water saturation for porous particles[J],2019,116(17).
APA	David R.O..,Marcolli C..,Fahrni J..,Qiu Y..,Perez Sirkin Y.A..,...&Kanji Z.A..(2019).Pore condensation and freezing is responsible for ice formation below water saturation for porous particles.Proceedings of the National Academy of Sciences of the United States of America,116(17).
MLA	David R.O.,et al."Pore condensation and freezing is responsible for ice formation below water saturation for porous particles".Proceedings of the National Academy of Sciences of the United States of America 116.17(2019).