气候变化领域集成服务门户(CCPortal): Mechanisms of Convective Clustering During a 2-Day Rain Event in AMIE/DYNAMO

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DOI	10.1029/2019MS001907
	Mechanisms of Convective Clustering During a 2-Day Rain Event in AMIE/DYNAMO
	Cheng W.-Y.; Kim D.; Rowe A.; Moon Y.; Wang S.
发表日期	2020
ISSN	19422466
卷号	12 期号:3
英文摘要	Physical mechanisms that are key to observed convective clustering in 2-day rain events are examined. Previous analysis of the 2-day rain events during the Atmospheric Radiation Measurement Madden-Julian Oscillation Investigation Experiment (AMIE)/Dynamics of the Madden-Julian Oscillation (DYNAMO) field campaign data revealed two distinct phases of convective clustering. Using a cloud-system-resolving model, we perform a series of intervention experiments to investigate the underlying mechanisms for convective clustering in each phase. In the developing phase, in addition to previously emphasized processes such as the cold pool-updraft interaction and moisture-convection feedbacks, our results show that the vertical wind shear in the lower free troposphere is a critical factor for convective clustering. Stronger lower free-tropospheric wind shear increases the entrainment of environmental air into updrafts and prevents convective clouds from being omnipresent. This result suggests that stronger vertical wind shear in the lower free troposphere can help spatially organize the convection, even for non–squall-line-type convective systems. In the decaying phase, the cold pool-updraft interaction becomes less effective in aggregating convective clouds because the boundary layer is widely cooled by stratiform precipitation. Instead, the mesoscale downdraft driven by the stratiform precipitation becomes the dominant factor to maintain the relatively aggregated convection. Additionally, removing horizontal variations in radiative heating has no impact on convective clustering on this 2-day time scale, even in the decaying phase when stratiform clouds are widespread. The implication of these results for improving the representation of mesoscale convective organization in convection schemes is discussed. ©2020. The Authors.
英文关键词	cold pools; convective clustering; mesoscale moist patches; stratiform-driven mesoscale downdraft
语种	英语
scopus关键词	Air entrainment; Atmospheric radiation; Boundary layers; Climatology; Clouds; Storms; Troposphere; Atmospheric radiation measurements; Cloud system-resolving models; Horizontal variation; Madden-Julian oscillation; Moisture-convection feedback; Physical mechanism; Stratiform precipitation; Vertical wind shear; Rain; atmospheric convection; boundary layer; heating; precipitation (climatology); troposphere; wind shear
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156739
作者单位	Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, United States
推荐引用方式 GB/T 7714	Cheng W.-Y.,Kim D.,Rowe A.,et al. Mechanisms of Convective Clustering During a 2-Day Rain Event in AMIE/DYNAMO[J],2020,12(3).
APA	Cheng W.-Y.,Kim D.,Rowe A.,Moon Y.,&Wang S..(2020).Mechanisms of Convective Clustering During a 2-Day Rain Event in AMIE/DYNAMO.Journal of Advances in Modeling Earth Systems,12(3).
MLA	Cheng W.-Y.,et al."Mechanisms of Convective Clustering During a 2-Day Rain Event in AMIE/DYNAMO".Journal of Advances in Modeling Earth Systems 12.3(2020).