气候变化领域集成服务门户(CCPortal): Low-level mixed-phase clouds in a complex Arctic environment

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DOI	10.5194/acp-20-3459-2020
	Low-level mixed-phase clouds in a complex Arctic environment
	Gierens R.; Kneifel S.; D. Shupe M.; Ebell K.; Maturilli M.; Löhnert U.
发表日期	2020
ISSN	1680-7316
起始页码	3459
结束页码	3481
卷号	20 期号:6
英文摘要	Low-level mixed-phase clouds (MPCs) are common in the Arctic. Both local and large-scale phenomena influence the properties and lifetime of MPCs. Arctic fjords are characterized by complex terrain and large variations in surface properties. Yet, not many studies have investigated the impact of local boundary layer dynamics and their relative importance on MPCs in the fjord environment. In this work, we used a combination of ground-based remote sensing instruments, surface meteorological observations, radiosoundings, and reanalysis data to study persistent low-level MPCs at Ny-Ålesund, Svalbard, for a 2.5-year period. Methods to identify the cloud regime, surface coupling, and regional and local wind patterns were developed. We found that persistent low-level MPCs were most common with westerly winds, and the westerly clouds had a higher mean liquid (42 g m-2) and ice water path (16 g m-2) compared to those with easterly winds. The increased height and rarity of persistent MPCs with easterly free-tropospheric winds suggest the island and its orography have an influence on the studied clouds. Seasonal variation in the liquid water path was found to be minimal, although the occurrence of persistent MPCs, their height, and their ice water path all showed notable seasonal dependency. Most of the studied MPCs were decoupled from the surface (63 %-82 % of the time). The coupled clouds had 41 % higher liquid water path than the fully decoupled ones. Local winds in the fjord were related to the frequency of surface coupling, and we propose that katabatic winds from the glaciers in the vicinity of the station may cause clouds to decouple. We concluded that while the regional to large-scale wind direction was important for the persistent MPC occurrence and properties, the local-scale phenomena (local wind patterns in the fjord and surface coupling) also had an influence. Moreover, this suggests that local boundary layer processes should be described in models in order to present low-level MPC properties accurately.. © 2020 BMJ Publishing Group. All rights reserved.
语种	英语
scopus关键词	cloud cover; fjord; mesoscale meteorology; orography; seasonal variation; troposphere; westerly; wind direction; wind velocity; Arctic; Svalbard; Svalbard and Jan Mayen
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/247896
作者单位	Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany; Cooperative Institute for the Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, United States; Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, United States; Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
推荐引用方式 GB/T 7714	Gierens R.,Kneifel S.,D. Shupe M.,et al. Low-level mixed-phase clouds in a complex Arctic environment[J],2020,20(6).
APA	Gierens R.,Kneifel S.,D. Shupe M.,Ebell K.,Maturilli M.,&Löhnert U..(2020).Low-level mixed-phase clouds in a complex Arctic environment.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(6).
MLA	Gierens R.,et al."Low-level mixed-phase clouds in a complex Arctic environment".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.6(2020).