气候变化领域集成服务门户(CCPortal): Improving the representation of aggregation in a two-moment microphysical scheme with statistics of multi-frequency Doppler radar observations

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DOI	10.5194/acp-21-17133-2021
	Improving the representation of aggregation in a two-moment microphysical scheme with statistics of multi-frequency Doppler radar observations
	Karrer M.; Seifert A.; Ori D.; Kneifel S.
发表日期	2021
ISSN	1680-7316
起始页码	17133
结束页码	17166
卷号	21 期号:22
英文摘要	Aggregation is a key microphysical process for the formation of precipitable ice particles. Its theoretical description involves many parameters and dependencies among different variables that are either insufficiently understood or difficult to accurately represent in bulk microphysics schemes. Previous studies have demonstrated the valuable information content of multi-frequency Doppler radar observations to characterize aggregation with respect to environmental parameters such as temperature. Comparisons with model simulations can reveal discrepancies, but the main challenge is to identify the most critical parameters in the aggregation parameterization, which can then be improved by using the observations as constraints. In this study, we systematically investigate the sensitivity of physical variables, such as number and mass density, as well as the forward-simulated multi-frequency and Doppler radar observables, to different parameters in a two-moment microphysics scheme. Our approach includes modifying key aggregation parameters such as the sticking efficiency or the shape of the size distribution. We also revise and test the impact of changing functional relationships (e.g., the terminal velocity-size relation) and underlying assumptions (e.g., the definition of the aggregation kernel). We test the sensitivity of the various components first in a single-column "snowshaft"model, which allows fast and efficient identification of the parameter combination optimally matching the observations. We find that particle properties, definition of the aggregation kernel, and size distribution width prove to be most important, while the sticking efficiency and the cloud ice habit have less influence. The setting which optimally matches the observations is then implemented in a 3D model using the identical scheme setup. Rerunning the 3D model with the new scheme setup for a multi-week period revealed that the large overestimation of aggregate size and terminal velocity in the model could be substantially reduced. The method presented is expected to be applicable to constrain other ice microphysical processes or to evaluate and improve other schemes. © 2021 Markus Karrer et al.
语种	英语
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/246416
作者单位	Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany; Deutscher Wetterdienst, Offenbach, Germany
推荐引用方式 GB/T 7714	Karrer M.,Seifert A.,Ori D.,et al. Improving the representation of aggregation in a two-moment microphysical scheme with statistics of multi-frequency Doppler radar observations[J],2021,21(22).
APA	Karrer M.,Seifert A.,Ori D.,&Kneifel S..(2021).Improving the representation of aggregation in a two-moment microphysical scheme with statistics of multi-frequency Doppler radar observations.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(22).
MLA	Karrer M.,et al."Improving the representation of aggregation in a two-moment microphysical scheme with statistics of multi-frequency Doppler radar observations".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.22(2021).