气候变化领域集成服务门户(CCPortal): No anomalous supersaturation in ultracold cirrus laboratory experiments

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DOI	10.5194/acp-20-1089-2020
	No anomalous supersaturation in ultracold cirrus laboratory experiments
	Clouser B.W.; Lamb K.D.; Sarkozy L.C.; Habig J.; Ebert V.; Saathoff H.; Möhler O.; Moyer E.J.
发表日期	2020
ISSN	16807316
起始页码	1089
结束页码	1103
卷号	20 期号:2
英文摘要	High-altitude cirrus clouds are climatically important: their formation freeze-dries air ascending to the stratosphere to its final value, and their radiative impact is disproportionately large. However, their formation and growth are not fully understood, and multiple in situ aircraft campaigns have observed frequent and persistent apparent water vapor supersaturations of 5 %-25 % in ultracold cirrus (T<205 K), even in the presence of ice particles. A variety of explanations for these observations have been put forth, including that ultracold cirrus are dominated by metastable ice whose vapor pressure exceeds that of hexagonal ice. The 2013 IsoCloud campaign at the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud and aerosol chamber allowed explicit testing of cirrus formation dynamics at these low temperatures. A series of 28 experiments allows robust estimation of the saturation vapor pressure over ice for temperatures between 189 and 235 K, with a variety of ice nucleating particles. Experiments are rapid enough (∼10 min) to allow detection of any metastable ice that may form, as the timescale for annealing to hexagonal ice is hours or longer over the whole experimental temperature range. We show that in all experiments, saturation vapor pressures are fully consistent with expected values for hexagonal ice and inconsistent with the highest values postulated for metastable ice, with no temperature-dependent deviations from expected saturation vapor pressure. If metastable ice forms in ultracold cirrus clouds, it appears to have a vapor pressure indistinguishable from that of hexagonal ice to within about 4.5 %. © 2020 Author(s).
关键词	atmospheric chemistry cirrus experimental study laboratory method stratosphere supersaturation vapor pressure water vapor
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132270
推荐引用方式 GB/T 7714	Clouser B.W.,Lamb K.D.,Sarkozy L.C.,et al. No anomalous supersaturation in ultracold cirrus laboratory experiments[J]. Atmospheric Chemistry and Physics,2020,20(2).
APA	Clouser B.W..,Lamb K.D..,Sarkozy L.C..,Habig J..,Ebert V..,...&Moyer E.J..(2020).No anomalous supersaturation in ultracold cirrus laboratory experiments.,20(2).
MLA	Clouser B.W.,et al."No anomalous supersaturation in ultracold cirrus laboratory experiments".20.2(2020).