气候变化领域集成服务门户(CCPortal): Processes contributing to cloud dissipation and formation events on the North Slope of Alaska

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DOI	10.5194/acp-21-4149-2021
	Processes contributing to cloud dissipation and formation events on the North Slope of Alaska
	Sedlar J.; Igel A.; Telg H.
发表日期	2021
ISSN	1680-7316
起始页码	4149
结束页码	4167
卷号	21 期号:5
英文摘要	Clear-sky periods across the high latitudes have profound impacts on the surface energy budget and lower atmospheric stratification; however an understanding of the atmospheric processes leading to low-level cloud dissipation and formation events is limited. A method to identify clear periods at UtqiaÄ¡vik (formerly Barrow), Alaska, during a 5-year period (2014-2018) is developed. A suite of remote sensing and in situ measurements from the high-latitude observatory are analyzed; we focus on comparing and contrasting atmospheric properties during low-level (below 2 km) cloud dissipation and formation events to understand the processes controlling clear-sky periods. Vertical profiles of lidar backscatter suggest that aerosol presence across the lower atmosphere is relatively invariant during the periods bookending clear conditions, which suggests that a sparsity of aerosol is not frequently a cause for cloud dissipation on the North Slope of Alaska. Further, meteorological analysis indicates two active processes ongoing that appear to support the formation of low clouds after a clear-sky period: namely, horizontal advection, which was dominant in winter and early spring, and quiescent air mass modification, which was dominant in the summer. During summer, the dominant mode of cloud formation is a low cloud or fog layer developing near the surface. This low cloud formation is driven largely by air mass modification under relatively quiescent synoptic conditions. Near-surface aerosol particles concentrations changed by a factor of 2 around summer formation events. Thermodynamic adjustment and increased aerosol presence under quiescent atmospheric conditions are hypothesized as important mechanisms for fog formation. © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	advection; aerosol; air mass; backscatter; clear sky; cloud cover; cloud microphysics; energy budget; formation mechanism; in situ measurement; remote sensing; stratification; vertical profile; Alaska; North Slope; United States
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/247052
作者单位	Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, United States; Noaa Global Monitoring Laboratory, Boulder, CO, United States; Department of Land Air, and Water Resources, University of California Davis, Davis, CA, United States
推荐引用方式 GB/T 7714	Sedlar J.,Igel A.,Telg H.. Processes contributing to cloud dissipation and formation events on the North Slope of Alaska[J],2021,21(5).
APA	Sedlar J.,Igel A.,&Telg H..(2021).Processes contributing to cloud dissipation and formation events on the North Slope of Alaska.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(5).
MLA	Sedlar J.,et al."Processes contributing to cloud dissipation and formation events on the North Slope of Alaska".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.5(2021).