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DOI	10.5194/acp-21-6681-2021
	Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud
	Ramelli F.; Henneberger J.; David R.O.; Bu&die; hl J.; Radenz M.; Seifert P.; Wieder J.; Lauber A.; Pasquier J.T.; Engelmann R.; Mignani C.; Hervo M.; Lohmann U.
发表日期	2021
ISSN	1680-7316
起始页码	6681
结束页码	6706
卷号	21 期号:9
英文摘要	The seeder-feeder mechanism has been observed to enhance orographic precipitation in previous studies. However, the microphysical processes active in the seeder and feeder region are still being understood. In this paper, we investigate the seeder and feeder region of a mixed-phase cloud passing over the Swiss Alps, focusing on (1) fallstreaks of enhanced radar reflectivity originating from cloud top generating cells (seeder region) and (2) a persistent lowlevel feeder cloud produced by the boundary layer circulation (feeder region). Observations were obtained from a multidimensional set of instruments including ground-based remote sensing instrumentation (Ka-band polarimetric cloud radar, microwave radiometer, wind profiler), in situ instrumentation on a tethered balloon system, and ground-based aerosol and precipitation measurements. The cloud radar observations suggest that ice formation and growth were enhanced within cloud top generating cells, which is consistent with previous observational studies. However, uncertainties exist regarding the dominant ice formation mechanism within these cells. Here we propose different mechanisms that potentially enhance ice nucleation and growth in cloud top generating cells (convective overshooting, radiative cooling, droplet shattering) and attempt to estimate their potential contribution from an ice nucleating particle perspective. Once ice formation and growth within the seeder region exceeded a threshold value, the mixedphase cloud became fully glaciated. Local flow effects on the lee side of the mountain barrier induced the formation of a persistent low-level feeder cloud over a small-scale topographic feature in the inner-Alpine valley. In situ measurements within the low-level feeder cloud observed the production of secondary ice particles likely due to the Hallett-Mossop process and ice particle fragmentation upon ice-ice collisions. Therefore, secondary ice production may have been partly responsible for the elevated ice crystal number concentrations that have been previously observed in feeder clouds at mountaintop observatories. Secondary ice production in feeder clouds can potentially enhance orographic precipitation. © 2021 EDP Sciences. All rights reserved.
语种	英语
scopus关键词	aerosol; alpine environment; cloud microphysics; cloud seeding; formation mechanism; ground-based measurement; ice crystal; in situ measurement; orographic effect; precipitation (climatology); wind profile
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/246927
作者单位	Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland; Department of Geosciences, University of Oslo, Oslo, Norway; Leibniz Institute for Tropospheric Research, Leipzig, Germany; Department of Environmental Sciences, University of Basel, Basel, Switzerland; Federal Office of Meteorology and Climatology MeteoSwiss, Payerne, Switzerland
推荐引用方式 GB/T 7714	Ramelli F.,Henneberger J.,David R.O.,et al. Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud[J],2021,21(9).
APA	Ramelli F..,Henneberger J..,David R.O..,Bu&die.,hl J..,...&Lohmann U..(2021).Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(9).
MLA	Ramelli F.,et al."Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.9(2021).