DOI: 10.1016/j.atmosres.2018.04.026
Scopus记录号: 2-s2.0-85047435685
论文题名: Return times and return levels of July–September extreme rainfall over the major climatic sub-regions in Sahel
作者: Chamani R. ; Monkam D. ; Yepdo Djomou Z.
刊名: Atmospheric Research
ISSN: 1698095
出版年: 2018
卷: 212 起始页码: 77
结束页码: 90
语种: 英语
英文关键词: Extreme rainfall
; Fractional area
; Peaks-over-threshold
; Return levels
; Return times
; Sahel
Scopus关键词: Pareto principle
; Extreme rainfall
; Fractional area
; Peaks over threshold
; Return level
; Return-times
; Sahel
; Rain
英文摘要: Return times (RTs) and return levels (RLs) of July–September (JAS) extreme rainfall are estimated using stationary peaks-over-threshold approach through generalized pareto distribution (GPD) over the three climatic sub-regions in Sahel. Monthly rainfall data from the Climatic Research Unit were used. The period of analysis goes from 1901 to 2009. Results computed for both accumulated JAS rainfall and fractional area of extreme rainfall, indicate that JAS extreme rainfall in semiarid and sub-humid sub-regions were more frequent in the postchange period of 1971–2009 than in the prechange period of 1901–1970. The RLs of these extremes have greatly decreased after 1970. The changes at JAS extreme tails of the distribution have significantly contributed to the decrease in mean of JAS rainfall after 1970. Predicted 40-year RL shows that over each sub-region, JAS extreme rainfall are expected to be more severe after the postchange period. For the postchange period, 1999 has been detected as the most extreme year in arid and semiarid sub-regions, and 2008 in sub-humid sub-region. These events were found occurred during the manifestation of moderate La Niña. The spatial distributions of accumulated JAS rainfall associated with these years show that highest values were concentrated along the coastline of semiarid and sub-humid sub-regions, and the lowest values in the northern part of the arid sub-region. Using the GPD, the JAS extreme rainfall (fractional area) associated with 1999 and 2008 are expected at least once every 144 (40), 99 (17) and 197 (67) yr in arid, semi-arid and sub-humid sub-regions, respectively. These results highlight the importance of an analysis of extreme rainfall in Sahel based on climatic sub-regions. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/108810
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
There are no files associated with this item.
作者单位: Laboratory of Fundamental Physics, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon; Department of Physics, Faculty of Science, University of Yaounde I, P.O. Box 812Yaounde, Cameroon; Department of Physics, Faculty of Science, University of Douala, P.O. Box 24157, Douala, Cameroon; National Institute of Cartography, P.O.Box 157Yaounde, Cameroon
Recommended Citation:
Chamani R.,Monkam D.,Yepdo Djomou Z.. Return times and return levels of July–September extreme rainfall over the major climatic sub-regions in Sahel[J]. Atmospheric Research,2018-01-01,212