气候变化领域集成服务门户(CCPortal): Shape dependence of snow crystal fall speed

CCPortal

DOI	10.5194/acp-21-7545-2021
	Shape dependence of snow crystal fall speed
	Vázquez-Martín S.; Kuhn T.; Eliasson S.
发表日期	2021
ISSN	1680-7316
起始页码	7545
结束页码	7565
卷号	21 期号:10
英文摘要	Improved snowfall predictions require accurate knowledge of the properties of ice crystals and snow particles, such as their size, cross-sectional area, shape, and fall speed. The fall speed of ice particles is a critical parameter for the representation of ice clouds and snow in atmospheric numerical models, as it determines the rate of removal of ice from the modelled clouds. Fall speed is also required for snowfall predictions alongside other properties such as ice particle size, cross-sectional area, and shape. For example, shape is important as it strongly influences the scattering properties of these ice particles and thus their response to remote sensing techniques. This work analyzes fall speed as a function of particle size (maximum dimension), cross-sectional area, and shape using ground-based in situ measurements. The measurements for this study were done in Kiruna, Sweden, during the snowfall seasons of 2014 to 2019, using the ground-based in situ instrument Dual Ice Crystal Imager (D-ICI). The resulting data consist of high-resolution images of falling hydrometeors from two viewing geometries that are used to determine particle size (maximum dimension), cross-sectional area, area ratio, orientation, and the fall speed of individual particles. The selected dataset covers sizes from about 0.06 to 3.2 mm and fall speeds from 0.06 to 1.6 m sspan classCombining double low line"inline-formula"-1span. Relationships between particle size, cross-sectional area, and fall speed are studied for different shapes. The data show in general low correlations to fitted fall speed relationships due to large spread observed in fall speed. After binning the data according to size or cross-sectional area, correlations improve, and we can report reliable parameterizations of fall speed vs. particle size or cross-sectional area for part of the shapes. For most of these shapes, the fall speed is better correlated with cross-sectional area than with particle size. The effects of orientation and area ratio on the fall speed are also studied, and measurements show that vertically oriented particles fall faster on average. However, most particles for which orientation can be defined fall horizontally. © 2021 Copernicus GmbH. All rights reserved.
语种	英语
scopus关键词	atmospheric convection; climate modeling; cloud microphysics; ice crystal; numerical model; particle size; shape; snow; Kiruna; Norrbotten; Sweden
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/246883
作者单位	Luleä University of Technology (LTU), Department of Computer Science, Electrical and Space Engineering, Division of Space Technology, Kiruna, 98 128, Sweden; Swedish Meteorological and Hydrological Institute (SMHI), Norrköping, 601 76, Sweden
推荐引用方式 GB/T 7714	Vázquez-Martín S.,Kuhn T.,Eliasson S.. Shape dependence of snow crystal fall speed[J],2021,21(10).
APA	Vázquez-Martín S.,Kuhn T.,&Eliasson S..(2021).Shape dependence of snow crystal fall speed.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(10).
MLA	Vázquez-Martín S.,et al."Shape dependence of snow crystal fall speed".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.10(2021).