气候变化领域集成服务门户(CCPortal): The North African coastal low level wind jet: a high resolution view

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DOI	10.1007/s00382-018-4441-7
	The North African coastal low level wind jet: a high resolution view
	Soares P.M.M.; Lima D.C.A.; Semedo Á.; Cardoso R.M.; Cabos W.; Sein D.
发表日期	2019
ISSN	0930-7575
起始页码	1211
结束页码	1230
卷号	53 期号:2020-01-02
英文摘要	The North African coastal low-level jet (NACLLJ) lies over the cold Canary current and is synoptically linked to the Azores Anticyclone and to the continental thermal low over the Sahara Desert. Although being one of the most persistent and horizontally extended coastal wind jets, this is the first high resolution modelling effort to investigate the NACLLJ climate. The current study uses a ROM atmospheric hindcast simulation with ~ 25 km resolution, for the period 1980–2014. Additionally, the underlying surface wind features are also scrutinized using the CORDEX-Africa runs. These runs allow the building of a multi-model ensemble for the coastal surface flow. The ROM and the CORDEX-Africa simulations are extensively evaluated showing a good ability to represent the surface winds. The NACLLJ shows a strong seasonal cycle, but, unlike most coastal wind jets, e.g. the California one, it is significantly present all year round, with frequencies of occurrence above 20%. In spring and autumn, the maxima frequencies are around 50%, and reach values above 60% in summer. The location of maximum frequency of occurrence migrates meridionally from season to season, being in winter and spring upwind of Cap-Vert, and in summer and autumn offshore the Western Sahara. Analogously, the lowest jet wind speeds occur in winter, when the median is below 15 m/s. In summer, the jet wind speed median values are ~ 20 m/s and the maxima are above 30 m/s. The jet occurs at heights ~ 360 m. A momentum balance is pursued disclosing that the regional flow is almost geostrophic, dominated by the pressure gradient and Coriolis force. Over the jet areas the ageostrophy is responsible for the jet acceleration. © 2018, The Author(s).
英文关键词	Africa; Coastal low-level wind jet; CORDEX; Regional climate modelling; ROM (REMO-OASIS-MPIOM); Upwelling
语种	英语
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146220
作者单位	Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Ed. C8 (3.26), Lisbon, 1749-016, Portugal; Department of Water Science and Engineering, IHE Delft, Delft, Netherlands; Department of Physics, University of Alcalá, Alcalá de Henares, Madrid, Spain; Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, Bremerhaven, 27568, Germany; Shirshov Institute of Oceanology, Russian Academy of Science, 36 Nahimovskiy Prospect, Moscow, 117997, Russian Federation
推荐引用方式 GB/T 7714	Soares P.M.M.,Lima D.C.A.,Semedo Á.,et al. The North African coastal low level wind jet: a high resolution view[J],2019,53(2020-01-02).
APA	Soares P.M.M.,Lima D.C.A.,Semedo Á.,Cardoso R.M.,Cabos W.,&Sein D..(2019).The North African coastal low level wind jet: a high resolution view.Climate Dynamics,53(2020-01-02).
MLA	Soares P.M.M.,et al."The North African coastal low level wind jet: a high resolution view".Climate Dynamics 53.2020-01-02(2019).