DOI: 10.1175/JCLI-D-15-0265.1
Scopus记录号: 2-s2.0-84949983719
论文题名: The West African monsoon onset: A concise comparison of definitions
作者: Fitzpatrick R.G.J. ; Bain C.L. ; Knippertz P. ; Marsham J.H. ; Parker D.J.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 22 起始页码: 8673
结束页码: 8694
语种: 英语
Scopus关键词: Climate change
; Forecasting
; Weather forecasting
; Africa
; Geographic location
; Intraseasonal variability
; Monsoons
; Numerical weather prediction/forecasting
; Seasonal forecasting
; Variability
; Atmospheric thermodynamics
英文摘要: The onset of the West African monsoon (WAM) marks a vital time for local and regional stakeholders. While the seasonal progression of monsoon winds and the related migration of precipitation from the Guinea Coast toward the Sudan/Sahel is apparent, there exist contrasting man-made definitions of what the WAM onset means. Broadly speaking, onset can be analyzed regionally, locally, or over a designated intermediate scale. There are at least 18 distinct definitions of the WAM onset in publication, with little work done on comparing observed onset from different definitions or comparing onset realizations across different datasets and resolutions. Here, nine definitions have been calculated using multiple datasets of different metrics at different resolutions. It is found that mean regional onset dates are consistent across multiple datasets and different definitions. There is low interannual variability in regional onset, suggesting that regional seasonal forecasting of the onset provides few benefits over climatology. In contrast, local onsets show high spatial, interannual, and interdefinition variability. Furthermore, it is found that there is little correlation between local onset dates and regional onset dates across West Africa, implying a disharmony between regional measures of onset and the experience on a local scale. The results of this study show that evaluation of seasonal monsoon onset forecasts is far from straightforward. Given a seasonal forecasting model, it is possible to simultaneously have a good and a bad prediction of monsoon onset simply through selection of the onset definition and observational dataset used for comparison. © 2015 American Meteorological Society. 资助项目: CASE, Center for Advanced Systems and Engineering, Syracuse University
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50826
Appears in Collections: 气候变化事实与影响
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作者单位: University of Leeds, Leeds, United Kingdom; Met Office, Exeter, United Kingdom; Karlsruhe Institute of Technology, Karlsruhe, Germany; Institute for Climate and Atmospheric Science, University of Leeds, Leeds, United Kingdom
Recommended Citation:
Fitzpatrick R.G.J.,Bain C.L.,Knippertz P.,et al. The West African monsoon onset: A concise comparison of definitions[J]. Journal of Climate,2015-01-01,28(22)