气候变化领域集成服务门户(CCPortal): Mixed-phase orographic cloud microphysics during StormVEx and IFRACS

CCPortal

DOI	10.5194/acp-19-5387-2019
	Mixed-phase orographic cloud microphysics during StormVEx and IFRACS
	Lowenthal D.H.; Hallar A.G.; David R.O.; Mccubbin I.B.; Borys R.D.; Mace G.G.
发表日期	2019
ISSN	16807316
起始页码	5387
结束页码	5401
卷号	19 期号:8
英文摘要	Wintertime mixed-phase orographic cloud (MPC) measurements were conducted at the Storm Peak Laboratory (SPL) during the Storm Peak Lab Cloud Property Validation Experiment (StormVEx) and Isotopic Fractionation in Snow (IFRACS) programs in 2011 and 2014, respectively. The data include 92 h of simultaneous measurements of supercooled liquid cloud droplet and ice particle size distributions (PSDs). Average cloud droplet number concentration (CDNC), droplet size (NMD), and liquid water content (LWC) were similar in both years, while ice particle concentration (Ni) and ice water content (IWC) were higher during IFRACS. The consistency of the liquid cloud suggests that SPL is essentially a cloud chamber that produces a consistent cloud under moist, westerly flow during the winter. A variable cloud condensation nuclei (CCN)-related inverse relationship between CDNC and NMD strengthened when the data were stratified by LWC. Some of this variation is due to changes in cloud base height below SPL. While there was a weak inverse correlation between LWC and IWC in the data as a whole, a stronger relationship was demonstrated for a case study on 9 February 2014 during IFRACS. A minimum LWC of 0.05 gm3 showed that the cloud was not completely glaciated on this day. Erosion of the droplet distribution at high IWC was attributed to the Wegener- Bergeron-Findeisen process as the high IWC was accompanied by a 10-fold increase in Ni. A relationship between large cloud droplet concentration (25-35 ?m) and small ice particles (75-200 ?m) under cold (< 8 -C) but not warm (> 8 -C) conditions during IFRACS suggests primary ice particle production by contact or immersion freezing. The effect of blowing snow was evaluated from the relationship between wind speed and Ni and by comparing the relative (percent) ice particle PSDs at high and low wind speeds. These were similar, contrary to expectation for blowing snow. However, the correlation between wind speed and ice crystal concentration may support this explanation for high crystal concentrations at the surface. Secondary processes could have contributed to high crystal concentrations but there was no direct evidence to support this. Further experimental work is needed to resolve these issues. © Author(s) 2019.
语种	英语
scopus关键词	cloud condensation nucleus; cloud droplet; cloud microphysics; concentration (composition); correlation; ice cover; isotopic fractionation; measurement method; orography; water content; wind velocity; winter
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/144465
作者单位	Desert Research Institute, 2215 Raggio Pkwy, Reno, NV 89509, United States; Department of Atmospheric Sciences, University of Utah, 135S1460E, Salt Lake City, UT 84112, United States; ETH Zürich, Universitätstrasse 16, Zürich, 8092, Switzerland; Department of Geosciences, University of Oslo, P.O. Box 1022, Blindern, Oslo, 0315, Norway
推荐引用方式 GB/T 7714	Lowenthal D.H.,Hallar A.G.,David R.O.,et al. Mixed-phase orographic cloud microphysics during StormVEx and IFRACS[J],2019,19(8).
APA	Lowenthal D.H.,Hallar A.G.,David R.O.,Mccubbin I.B.,Borys R.D.,&Mace G.G..(2019).Mixed-phase orographic cloud microphysics during StormVEx and IFRACS.Atmospheric Chemistry and Physics,19(8).
MLA	Lowenthal D.H.,et al."Mixed-phase orographic cloud microphysics during StormVEx and IFRACS".Atmospheric Chemistry and Physics 19.8(2019).