DOI: 10.1175/JCLI-D-16-0144.1
Scopus记录号: 2-s2.0-85014543433
论文题名: Statistical connection between the Madden-Julian oscillation and large daily precipitation events in West Africa
作者: Sossa A. ; Liebmann B. ; Bladé I. ; Allured D. ; Hendon H.H. ; Peterson P. ; Hoell A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2017
卷: 30, 期: 6 起始页码: 1999
结束页码: 2010
语种: 英语
Scopus关键词: Atmospheric thermodynamics
; Climate change
; Climatology
; Floods
; Modulation
; Rain
; Africa
; Interannual variation
; Intertropical convergence zone
; Intraseasonal variability
; Madden-Julian oscillation
; Oscillations
; Seasonal mean rainfall
; Seasonal precipitations
; Precipitation (meteorology)
; air-sea interaction
; annual variation
; equatorial dynamics
; intertropical convergence zone
; Madden-Julian oscillation
; monsoon
; precipitation intensity
; rainfall
; seasonal variation
; West Africa
英文摘要: This study focuses on the impact of the Madden-Julian oscillation (MJO)-as monitored by a well-known multivariate index-on large daily precipitation events in West Africa for the period 1981-2014. Two seasons are considered: the near-equatorial wet season in March-May (MAM) and the peak of the West African monsoon during July-September (JAS), when the intertropical convergence zone (ITCZ) is at its most northerly position. Although the MJO-related interannual variation of seasonal mean rainfall is large, the focus here is on the impacts of the MJO on daily time scales because variations in the frequency of intense, short-term, flood-causing, rainfall events are more important for West African agriculture than variations in seasonal precipitation, particularly near the Guinean coast, where precipitation is abundant. Using composites based on thresholds of daily precipitation amounts, changes in mean precipitation and frequency of the heaviest daily events associated with the phase of the MJO are investigated. The expected modulation of mean rainfall by the MJO is much stronger during MAM than during JAS; yet the modulation of the largest events (i.e., daily rainfall rates above the 90th percentile) is comparable in both seasons. Conservative statistical tests of local and field significance indicate unambiguous impacts of the MJO of the expected sign during certain phases, but the nature of the impact depends on the local seasonal precipitation regime. For instance, in JAS, the early stages of the MJO increase the risk of flooding in the Sahel monsoon region while providing relief to the dry southern coast. © 2017 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/49759
Appears in Collections: 气候变化事实与影响
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作者单位: Significant Opportunities in Atmospheric Research and Science, UCAR, Boulder, CO, United States; Department of Civil Engineering, The City College of New York, New York, NY, United States; CIRES, University of Colorado, Boulder, CO, United States; Physical Sciences Division, NOAA/Earth System Research Laboratory, Boulder, CO, United States; Secció de Meteorologia, Department de Fisica Aplicada, Universitat de Barcelona, Barcelona, Spain; Bureau of Meteorology Research Centre, Melbourne, VIC, Australia; Climate Hazards Group, Department of Geography, University of California, Santa Barbara, Santa Barbara, CA, United States
Recommended Citation:
Sossa A.,Liebmann B.,Bladé I.,et al. Statistical connection between the Madden-Julian oscillation and large daily precipitation events in West Africa[J]. Journal of Climate,2017-01-01,30(6)