DOI: 10.1175/JCLI-D-14-00333.1
Scopus记录号: 2-s2.0-84921632617
论文题名: Regional atmospheric circulation and rainfall variability in south equatorial Africa
作者: Dezfuli A.K. ; Zaitchik B.F. ; Gnanadesikan A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 2 起始页码: 809
结束页码: 818
语种: 英语
Scopus关键词: Pressure gradient
; Asymmetric patterns
; Atmospheric circulation
; Daily precipitations
; Equatorial Africa
; Rainfall variability
; Tropical atlantic
; Weather scale
; Westerly winds
; Precipitation (meteorology)
; atmospheric circulation
; atmospheric convection
; climate variation
; precipitation (climatology)
; pressure gradient
; rainfall
; regional climate
; wind
; Africa
; Atlantic Ocean
; Atlantic Ocean (Tropical)
; East African Plateau
; Indian Ocean
; Indian Ocean (Southwest)
英文摘要: This study examines daily precipitation data duringDecember-March over south equatorial Africa (SEA) and proposes a new zonal asymmetric pattern (ZAP) that explains the leading mode of weather-scale precipitation variability in the region. The eastern and western components of the ZAP, separated at about 30°E, appear to be a consequence of an anomalous zonal atmospheric cell triggered by enhanced low-level westerly winds. The enhanced westerlies are generated by a diagonal interhemispheric pressure gradient between the southwestern Indian and north tropical Atlantic Oceans. In eastern SEA these winds hit the East African Plateau, producing low-level convergence and convection that further intensifies the westerlies. In western SEA a subsiding branch develops in response, closing the circulation cell. The system gradually dissipates as the pressure gradient weakens. Through this mechanism, simultaneous changes in two hemispheres generate a regional zonally oriented circulation that relies on climatic communication between eastern and western equatorial Africa. © 2015 American Meteorological Society. 资助项目: NASA, National Aeronautics and Space Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50445
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, United States
Recommended Citation:
Dezfuli A.K.,Zaitchik B.F.,Gnanadesikan A.. Regional atmospheric circulation and rainfall variability in south equatorial Africa[J]. Journal of Climate,2015-01-01,28(2)