干旱区生态环境知识资源中心(Arid): The Saharan convective boundary layer structure over large scale surface heterogeneity: A large eddy simulation study

Arid

DOI	10.1016/j.atmosres.2020.105250
	The Saharan convective boundary layer structure over large scale surface heterogeneity: A large eddy simulation study
	Papangelis, Georgios; Tombrou, Maria; Kalogiros, John
通讯作者	Papangelis, G
来源期刊	ATMOSPHERIC RESEARCH
ISSN	0169-8095
EISSN	1873-2895
出版年	2021
卷号	248
英文摘要	Extreme atmospheric and surface conditions over the vast Saharan desert result in the development of one of the deepest atmospheric boundary layers (Saharan Atmospheric Boundary Layer, SABL) on the planet. The land cover in the Sahara mainly consists of wide interchanging areas of stony and sandy desert intercepted by narrower bare rock formations. Significant changes in surface albedo, surface temperature, turbulence fluxes and wind speed have been observed with remote measurement platforms like aircraft and satellites. This was a motivation to simulate the convective boundary layer (CBL) that develops over the heterogeneous Saharan surface with a two-way coupled system of a large eddy simulation code (LES) and a land surface model (LSM). Initial and boundary conditions are provided by airborne observations and mesoscale atmospheric simulations. In order to investigate the effect of surface heterogeneity on the vertical structure of the SABL, a large scale (larger than 10 km) idealized warm surface anomaly is simulated and analyzed. A land strip with a low surface albedo produces almost doubled fluxes in density and stronger convergence near the ground than over the surrounding brighter surfaces. First and second order turbulence statistics reveal that strong thermals penetrate the inversion layer above the CBL producing a vigorous exchange between unstable and overlying stable air. Furthermore, a convective internal boundary layer (CIBL) is formed over the warm strip. The downwind development of the CIBL is studied and CBL depth equations from literature are revised. The average turbulent structure of the SABL reveals flow changes locally and downwind of the surface heterogeneity (strip), which can be more significant than the dispersive fluxes due to surface heterogeneity, and may have an important effect on processes such as dust uplift and its long range transport that influence weather and climate globally.
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000594097000003
WOS关键词	AERODYNAMIC ROUGHNESS LENGTH ; MINERAL DUST ; MESOSCALE ; MODEL ; CIRCULATIONS ; TRANSPORT ; DYNAMICS ; FIELD
WOS类目	Meteorology & Atmospheric Sciences
WOS研究方向	Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/328046
作者单位	[Papangelis, Georgios; Tombrou, Maria] Univ Athens, Dept Meteorol & Atmospher Phys, Athens, Greece; [Kalogiros, John] Nat Observ Athens, Inst Env Res & Sustainable Dev, Athens, Greece
推荐引用方式 GB/T 7714	Papangelis, Georgios,Tombrou, Maria,Kalogiros, John. The Saharan convective boundary layer structure over large scale surface heterogeneity: A large eddy simulation study[J],2021,248.
APA	Papangelis, Georgios,Tombrou, Maria,&Kalogiros, John.(2021).The Saharan convective boundary layer structure over large scale surface heterogeneity: A large eddy simulation study.ATMOSPHERIC RESEARCH,248.
MLA	Papangelis, Georgios,et al."The Saharan convective boundary layer structure over large scale surface heterogeneity: A large eddy simulation study".ATMOSPHERIC RESEARCH 248(2021).