| DOI: | 10.1175/JCLI-D-13-00693.1
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| Scopus记录号: | 2-s2.0-84905189390
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| 论文题名: | Modulation of daily precipitation over East Africa by the Madden-Julian oscillation |
| 作者: | Berhane F.; Zaitchik B.
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| 刊名: | Journal of Climate
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| ISSN: | 8948755
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| 出版年: | 2014
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| 卷: | 27, 期:15 | | 起始页码: | 6016
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| 结束页码: | 6034
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| 语种: | 英语
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| Scopus关键词: | Drought
; Heat convection
; Modulation
; Rain
; Weather forecasting
; Convergence/divergence
; Deep convection
; Madden-Julian oscillation
; Short-range predictions
; Walker circulation
; Climatology
; atmospheric convection
; climate prediction
; jet stream
; Madden-Julian oscillation
; precipitation (climatology)
; thermodynamics
; troposphere
; Walker circulation
; weather forecasting
; East Africa
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| 英文摘要: | Spatiotemporal variability in East African precipitation affects the livelihood of tens of millions of people. From the perspective of floods, flash droughts, and agriculture, variability on intraseasonal time scales is a critical component of total variability. The principal objective of this study is to explore subseasonal impacts of the Madden-Julian oscillation (MJO) on tropospheric circulations affecting East Africa (EA) during the long (March-May) and short (October-December) rains and associated variability in precipitation. Analyses are performed for 1979-2012 for dynamics and 1998-2012 for precipitation. Consistent with previous studies, significant MJO influence is found on wet and dry spells during the long and short rains. This influence, however, is found to vary within each season. Specifically, indices of MJO convection at 70°-80°E and 120°W are strongly associated with precipitation variability across much of EA in the early (March) and late (May) long rainy season and in the middle and late (November-December) short rainy season. In the early short rains (October) a different pattern emerges, in which MJO strength at 120°E (10°W) is associated with dry (wet) spells in coastal EA but not the interior. In April the MJO influence on precipitation is obscured but can be diagnosed in lead time associations. This diversity of influences reflects a diversity of mechanisms of MJO influence, including dynamic and thermodynamic mechanisms tied to large-scale atmospheric circulations and localized dynamics associated with MJO modulation of the Somali low-level jet. These differences are relevant to problems of subseasonal weather forecasts and climate projections for EA. © 2014 American Meteorological Society. |
| 资助项目: | NASA, National Aeronautics and Space Administration
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/51071
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| Appears in Collections: | 气候变化事实与影响
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作者单位: | Johns Hopkins University, Baltimore, MD, United States
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| Recommended Citation: | |
Berhane F.,Zaitchik B.. Modulation of daily precipitation over East Africa by the Madden-Julian oscillation[J]. Journal of Climate,2014-01-01,27(15)
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