气候变化领域集成服务门户(CCPortal): A new look at the environmental conditions favorable to secondary ice production

CCPortal

DOI	10.5194/acp-20-1391-2020
	A new look at the environmental conditions favorable to secondary ice production
	Korolev A.; Heckman I.; Wolde M.; Ackerman A.S.; Fridlind A.M.; Ladino L.A.; Paul Lawson R.; Milbrandt J.; Williams E.
发表日期	2020
ISSN	16807316
起始页码	1391
结束页码	1429
卷号	20 期号:3
英文摘要	This study attempts a new identification of mechanisms of secondary ice production (SIP) based on the observation of small faceted ice crystals (hexagonal plates or columns) with typical sizes smaller than 100 μ m. Due to their young age, such small ice crystals can be used as tracers for identifying the conditions for SIP. Observations reported here were conducted in oceanic tropical mesoscale convective systems (MCSs) and midlatitude frontal clouds in the temperature range from 0 to-15 °C and heavily seeded by aged ice particles. It was found that in both MCSs and frontal clouds, SIP was observed right above the melting layer and extended to higher altitudes with colder temperatures. The roles of six possible mechanisms to generate the SIP particles are assessed using additional observations. In most observed SIP cases, small secondary ice particles spatially correlated with liquid-phase, vertical updrafts and aged rimed ice particles. However, in many cases, neither graupel nor liquid drops were observed in the SIP regions, and therefore, the conditions for an active Hallett-Mossop process were not met. In many cases, large concentrations of small pristine ice particles were observed right above the melting layer, starting at temperatures as warm as-0:5 °C. It is proposed that the initiation of SIP above the melting layer is stimulated by the recirculation of large liquid drops through the melting layer with convective turbulent updrafts. After re-entering a supercooled environment above the melting layer, they impact with aged ice, freeze, and shatter. The size of the splinters generated during SIP was estimated as 10 μ m or less. A principal conclusion of this work is that only the freezingdrop-shattering mechanism could be clearly supported by the airborne in situ observations. © 2020 Author(s).
关键词	concentration (composition)convective system environmental conditions ice crystal in situ measurement marine atmosphere melting mesoscale motion turbulence
语种	英语
来源机构	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/132257
推荐引用方式 GB/T 7714	Korolev A.,Heckman I.,Wolde M.,et al. A new look at the environmental conditions favorable to secondary ice production[J]. Atmospheric Chemistry and Physics,2020,20(3).
APA	Korolev A..,Heckman I..,Wolde M..,Ackerman A.S..,Fridlind A.M..,...&Williams E..(2020).A new look at the environmental conditions favorable to secondary ice production.,20(3).
MLA	Korolev A.,et al."A new look at the environmental conditions favorable to secondary ice production".20.3(2020).