气候变化领域集成服务门户(CCPortal): Effect of Dust Load on the Cloud Top Ice-Water Partitioning Over Northern Middle to High Latitudes With CALIPSO Products

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DOI	10.1029/2020GL088030
	Effect of Dust Load on the Cloud Top Ice-Water Partitioning Over Northern Middle to High Latitudes With CALIPSO Products
	Kawamoto K.; Yamauchi A.; Suzuki K.; Okamoto H.; Li J.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:15
英文摘要	We quantified effects of dust load on the cloud top ice cloud fraction (ICF) in terms of the dust extinction coefficient (σext). We analyzed 3-year data sets obtained from an active satellite sensor over middle to high latitudes in the northern hemisphere for temperatures (T) between 230 and 273 K and σext values between 0.005 and 0.145 km−1. At about 250 K, ICF changed by about 30% in response to the above range of σext, whereas at extreme T values, ICF was relatively insensitive to σext. Thus, we concluded that ICF was primarily determined by T, with substantial influence of σext at about 250 K, likely due to increased opportunities for freezing as σext increases. Sensitivity of ICF was the lowest both at the largest σext and lowest T and at the smallest σext and highest T, while it was the highest at about 0.03 km−1 of σext and about 250 K. If there are any physical parameters that influence the ICF except temperature (T), how much does this parameter influence ICF in a given T? Dust particles have been long known as efficient ice nucleating particles. Although previous studies suggested that more dust particles increased ICF, they did not use quantitative parameters of the dust amount, but less-quantitative indicators such as relative dust frequency. Therefore, we used the dust extinction coefficient (σext) as a quantitative parameter of dust amount and examined the relationship between the dust amount and ICF for T between 230 and 273 K. We observed the following phenomena from satellite data. At about 250 K, ICF substantially depended on σext likely due to increased opportunities for freezing as σext increases. However, at extreme T values, ICF was relatively insensitive to σext. Moreover, we found that sensitivity of ICF was the lowest both at the largest σext and lowest T and at the smallest σext and highest T, while it was the highest at about 0.03 km−1 of σext and about 250 K. These behaviors of the ICF sensitivity could be understood from characteristics of T (the lower, the easier for freezing) and σext (the larger, the easier for freezing). © 2020. The Authors.
英文关键词	Freezing; Ice; Active satellites; Dust extinctions; Dust frequencies; Northern Hemispheres; Parameter influences; Physical parameters; Quantitative indicators; Quantitative parameters; Dust; CALIPSO; cloud cover; dust; extinction coefficient; Northern Hemisphere; satellite data; satellite sensor; temperature effect
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169989
作者单位	Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan; Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan; Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan; Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, China
推荐引用方式 GB/T 7714	Kawamoto K.,Yamauchi A.,Suzuki K.,et al. Effect of Dust Load on the Cloud Top Ice-Water Partitioning Over Northern Middle to High Latitudes With CALIPSO Products[J],2020,47(15).
APA	Kawamoto K.,Yamauchi A.,Suzuki K.,Okamoto H.,&Li J..(2020).Effect of Dust Load on the Cloud Top Ice-Water Partitioning Over Northern Middle to High Latitudes With CALIPSO Products.Geophysical Research Letters,47(15).
MLA	Kawamoto K.,et al."Effect of Dust Load on the Cloud Top Ice-Water Partitioning Over Northern Middle to High Latitudes With CALIPSO Products".Geophysical Research Letters 47.15(2020).