气候变化领域集成服务门户(CCPortal): A Sensitivity Study of Arctic Air-Mass Transformation Using Large Eddy Simulation

CCPortal

DOI	10.1029/2019JD031738
	A Sensitivity Study of Arctic Air-Mass Transformation Using Large Eddy Simulation
	Dimitrelos A.; Ekman A.M.L.; Caballero R.; Savre J.
发表日期	2020
ISSN	2169897X
卷号	125 期号:6
英文摘要	Arctic air mass transformation is linked to the evolution of low-level mixed-phase clouds. These clouds can alter the structure of the boundary layer and modify the surface energy budget. In this study, we use three-dimensional large eddy simulation and a bulk sea ice model to examine the lifecycle of clouds formed during wintertime advection of moist and warm air over sea ice, following a Lagrangian perspective. We investigate the stages of cloud formation, evolution, and decay. The results show that radiative cooling at the surface gives rise to fog formation which subsequently rises and transforms into a mixed-phase cloud. In our baseline simulation, the cloud persists for about 5 days and increases the surface temperature by on average 17 °C. Sensitivity tests show that the lifetime of the cloud is sensitive to changes in the vapor supply at cloud top. This flux is mainly impacted by changes in the divergence rate; an imposed convergence decreases the lifetime to 2 days while an imposed large-scale divergence increases the lifetime to more than 6 days. The largest difference in cloud radiative properties is found in the experiment with increased ice crystal number concentrations. In this case, the lifetime of the cloud is similar compared to baseline but the amount of liquid water is clearly depleted throughout the whole cloud sequence and the surface temperature is on average 6 °C cooler. The cloud condensation nuclei concentration has a weaker effect on the radiative properties and lifetime of the cloud. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	arctic air mass transformation; cloud lifetime; cloud radiative properties; entrainment at cloud top; Mixed-phase cloud formation; supercooled liquid layer at cloud top
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186089
作者单位	Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden; Department of Geography and Centre for Atmospheric Sciences, University of Cambridge, Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Dimitrelos A.,Ekman A.M.L.,Caballero R.,et al. A Sensitivity Study of Arctic Air-Mass Transformation Using Large Eddy Simulation[J],2020,125(6).
APA	Dimitrelos A.,Ekman A.M.L.,Caballero R.,&Savre J..(2020).A Sensitivity Study of Arctic Air-Mass Transformation Using Large Eddy Simulation.Journal of Geophysical Research: Atmospheres,125(6).
MLA	Dimitrelos A.,et al."A Sensitivity Study of Arctic Air-Mass Transformation Using Large Eddy Simulation".Journal of Geophysical Research: Atmospheres 125.6(2020).