气候变化领域集成服务门户(CCPortal): Large scale upper-level precursors for dust storm formation over North Africa and poleward transport to the Iberian Peninsula. Part I: An observational analysis

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DOI	10.1016/j.atmosenv.2020.117688
	Large scale upper-level precursors for dust storm formation over North Africa and poleward transport to the Iberian Peninsula. Part I: An observational analysis
	Orza J.A.G.; Dhital S.; Fiedler S.; Kaplan M.L.
发表日期	2020
ISSN	1352-2310
卷号	237
英文摘要	The analysis of three extreme African dust outbreaks over the Iberian Peninsula (IP) shows that a double Rossby wave breaking (RWB) process in the polar jet (PJ) creates the conditions for dust storm formation over subtropical deserts in North Africa and the restructuring of upper-level air flows critical for the dust transport poleward after ablation. Two consecutive anticyclonic RWBs initiate over the IP and the adjacent Atlantic, the first commencing 10 days before dust reaches the IP and the second three to five days later. The first RWB becomes quasi-stationary over the eastern Mediterranean when the second RWB develops. In turn, the first RWB blocks downstream propagation of the second, which is amplified by energy reflection poleward from the first break causing vortex intensification and equatorward propagation over the Atlas as well as a strengthening and coupling of the subtropical jet (STJ) to circulations in the ITCZ. Zonal flows are blocked and sustained low-level northeasterlies/easterlies are induced across northwest Africa. The three events present substantial differences in the location and geometry of key upper- and low-level subsynoptic features that organize the dust storms over the Sahara following the second break. Dust lifted by either the cold outflow from convective downdrafts or by orographic gravity waves interacts with terrain-induced and larger scale circulations and is transported to the IP. The location of the cyclonic large scale signal from the second RWB to the west or over the Atlas and the blocking of zonal flows are key for the poleward dust transport. © 2020 Elsevier Ltd
关键词	Multi-scale adjustment Poleward dust transport Rossby wave breaking Saharan dust storm Upper-level disturbance
语种	英语
scopus关键词	Arid regions; Atmospheric movements; Mechanical waves; Storms; Tropics; Convective downdrafts; Eastern Mediterranean; Energy reflection; Iberian Peninsula; Observational analysis; Orographic gravity waves; Quasi-stationary; Subtropical jet; Dust; cyclone; dust storm; geometry; gravity wave; Rossby wave; terrain; vortex; wave breaking; airflow; Article; circulation; cold; controlled study; dust storm; energy; geometry; gravity; meteorological phenomena; North Africa; observational study; priority journal; Rossby wave breaking; Iberian Peninsula; North Africa
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/249061
作者单位	SCOLAb, Department of Applied Physics, Universidad Miguel Hernández de Elche, Av. de la Universidad s/n, Elche, 03202, Spain; Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, United States; Institute of Geophysics and Meteorology, University of Cologne, Pohligstrasse 3, Cologne, 50969, Germany; Applied Meteorology Program, Embry-Riddle Aeronautical University, 3700 Willow Creek Road, Prescott, AZ 86301, United States
推荐引用方式 GB/T 7714	Orza J.A.G.,Dhital S.,Fiedler S.,et al. Large scale upper-level precursors for dust storm formation over North Africa and poleward transport to the Iberian Peninsula. Part I: An observational analysis[J],2020,237.
APA	Orza J.A.G.,Dhital S.,Fiedler S.,&Kaplan M.L..(2020).Large scale upper-level precursors for dust storm formation over North Africa and poleward transport to the Iberian Peninsula. Part I: An observational analysis.ATMOSPHERIC ENVIRONMENT,237.
MLA	Orza J.A.G.,et al."Large scale upper-level precursors for dust storm formation over North Africa and poleward transport to the Iberian Peninsula. Part I: An observational analysis".ATMOSPHERIC ENVIRONMENT 237(2020).