气候变化领域集成服务门户(CCPortal): Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon

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DOI	10.5194/acp-21-13207-2021
	Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon
	Henkes A.; Fisch G.; MacHado L.A.T.; Chaboureau J.-P.
发表日期	2021
ISSN	1680-7316
起始页码	13207
结束页码	13225
卷号	21 期号:17
英文摘要	Observations of the boundary layer (BL) processes are analyzed statistically for dry seasons of 2 years and in detail, as case studies, for 4 shallow convective days (ShCu) and 4 shallow-To-deep convective days (ShDeep) using a suite of ground-based measurements from the Observation and Modeling of the Green Ocean Amazon (GoAmazon 2014/5) Experiment. The BL stages in ShDeep days, from the nighttime to the cloudy mixing layer stage, are then described in comparison with ShCu days. Atmospheric thermodynamics and dynamics, environmental profiles, and surface turbulent fluxes were employed to compare these two distinct situations for each stage of the BL evolution. Particular attention is given to the morning transition stage, in which the BL changes from stable to unstable conditions in the early morning hours. Results show that the decrease in time duration of the morning transition on ShDeep days is associated with high humidity and well-established vertical wind shear patterns. Higher humidity since nighttime not only contributes to lowering the cloud base during the rapid growth of the BL but also contributes to the balance between radiative cooling and turbulent mixing during nighttime, resulting in higher sensible heat flux in the early morning. The sensible heat flux promotes rapid growth of the well-mixed layer, thus favoring the deeper BL starting from around 08:00gLST (UTC-4gh). Under these conditions, the time duration of morning transition is used to promote convection, having an important effect on the convective BL strength and leading to the formation of shallow cumulus clouds and their subsequent evolution into deep convective clouds. Statistical analysis was used to validate the conceptual model obtained from the case studies. Despite the case-To-case variability, the statistical analyses of the processes in the BL show that the described processes are very representative of cloud evolution during the dry season. © 2021 The Author(s).
语种	英语
scopus关键词	boundary layer; convective cloud; dry season; ground-based measurement; humidity; sensible heat flux; thermodynamics; turbulent mixing; wind shear; Amazonia
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/246608
作者单位	National Institute for Space Research, Cachoeira Paulista, São Paulo, Brazil; Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany; Laboratoire DAérologie, Université de Toulouse, Cnrs, Ups, Toulouse, France
推荐引用方式 GB/T 7714	Henkes A.,Fisch G.,MacHado L.A.T.,et al. Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon[J],2021,21(17).
APA	Henkes A.,Fisch G.,MacHado L.A.T.,&Chaboureau J.-P..(2021).Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(17).
MLA	Henkes A.,et al."Morning boundary layer conditions for shallow to deep convective cloud evolution during the dry season in the central Amazon".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.17(2021).