DOI: 10.1175/JCLI-D-14-00510.1
Scopus记录号: 2-s2.0-84949936093
论文题名: The Madden-Julian oscillation's influence on spring rainy season precipitation over equatorial West Africa
作者: Berhane F. ; Zaitchik B. ; Badr H.S.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 22 起始页码: 8653
结束页码: 8672
语种: 英语
Scopus关键词: Coastal zones
; Dynamics
; Gravity waves
; Heat convection
; Mechanical waves
; Precipitation (meteorology)
; Rain
; Africa
; Geographic location
; Kelvin waves
; Madden-Julian oscillation
; Rossby wave
; Climatology
英文摘要: This paper characterizes the influence of the Madden-Julian oscillation (MJO) on spring rainy season (March-June) convection variability over equatorial West Africa (EWA) and investigates mechanisms of association. It is found that the MJO has a significant impact on convection and precipitation anomalies over the region. Over large portions of EWA, MJO impacts on rainfall constitute a difference on the order of 20%-50% from average daily rain rates for the season. This impact is primarily due to the direct influence of the eastward movement of the MJO convective core into EWA, which is associated with westerly low-level wind anomalies that advect moisture from the Atlantic Ocean to the region. In addition, equatorial Rossby and Kelvin waves triggered by MJO convection anomalies over the Indian Ocean have a significant and systematic influence on EWA spring rainy season precipitation. The Kelvin wave contribution and the relative strength of the direct MJO convective influence compared to that of equatorial wave activity differs from findings of studies that have examined MJO influence on EWA during boreal summer. In addition, MJO is found to influence precipitation extremes during spring rains in a manner that is not observed in summer. Importantly, in this analysis the influences of MJO convection and each of the MJO-associated convectively coupled equatorial waves frequently coincide, reaching EWA approximately 20 days after MJO convection initiates in the Indian Ocean. This coincident timing enhances the total MJO impact on the region, and it also implies that MJO events have potential for prediction of regional-scale convection and rainfall anomalies over EWA in this season. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50504
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:
Berhane F.,Zaitchik B.,Badr H.S.. The Madden-Julian oscillation's influence on spring rainy season precipitation over equatorial West Africa[J]. Journal of Climate,2015-01-01,28(22)