DOI: 10.1175/JCLI-D-14-00746.1
Scopus记录号: 2-s2.0-84980338927
论文题名: Analysis of low-level atmospheric moisture transport associated with the West African monsoon
作者: Lélé M.I. ; Leslie L.M. ; Lamb P.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 11 起始页码: 4414
结束页码: 4430
语种: 英语
Scopus关键词: Atmospheric movements
; Atmospheric thermodynamics
; Budget control
; Climate change
; Fighter aircraft
; Rain
; Water vapor
; Climate variability
; Interannual variability
; Moisture/moisture budgets
; Seasonal cycle
; Seasonal variability
; Moisture
; air-sea interaction
; annual variation
; atmospheric moisture
; atmospheric transport
; climate variation
; moisture flux
; monsoon
; rainfall
; seasonal variation
; water vapor
; Atlantic Ocean
; Gulf of Guinea
; Sahel [Sub-Saharan Africa]
; Sudan
; West Africa
英文摘要: The major objective of this study is to re-evaluate the ocean-land transport of moisture for rainfall in West Africa using 1979-2008 NCEP-NCAR reanalysis data. The vertically integrated atmospheric water vapor flux for the surface-850 hPa is calculated to account for total low-level moisture flux contribution to rainfall over West Africa. Analysis of mean monthly total vapor fluxes shows a progressive penetration of the flux into West Africa from the south and west. During spring (April-June), the northward flux forms a "moisture river" transporting moisture current into the Gulf of Guinea coast. In the peak monsoon season (July-September), the southerly transport weakens, but westerly transport is enhanced and extends to 20°N owing to the strengthening West African jet offthe west coast. Mean seasonal values of total water vapor flux components across boundaries indicate that the zonal component is the largest contributor to mean moisture transport into the Sahel, while the meridional transport contributes the most over the Guinea coast. For the wet years of the Sahel rainy season (July-September), active anomalies are displaced farther north compared to the long-term average. This includes the latitude of the intertropical front (ITF), the extent of moisture flux, and the zone of strong moisture flux convergence, with an enhanced westerly flow. For the dry Sahel years, the opposite patterns are observed. Statistically significant positive correlations between the zonal moisture fluxes and Sudan-Sahel rainfall totals are most pronounced when the zonal fluxes lead by 1-4 pentads. However, although weak, they still are statistically significant at lags 3 and 4 for meridional moisture fluxes. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50388
Appears in Collections: 气候变化事实与影响
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作者单位: Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma, Norman, OK, United States; School of Meteorology, University of Oklahoma, Norman, OK, United States
Recommended Citation:
Lélé M.I.,Leslie L.M.,Lamb P.J.. Analysis of low-level atmospheric moisture transport associated with the West African monsoon[J]. Journal of Climate,2015-01-01,28(11)