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Communication incl. Poster: BibTeX citation key:  Janiga
Janiga, M. A. & Thorncroft, C. D. 2009. The impact of African easterly waves on the environment and characteristics of convection during the wet season. Work presented at Third International AMMA Conference, July 20—24, at Ouagadougou, Burkina Faso.
Added by: roussot 2009-11-04 19:33:35
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Categories: Atmospheric processes, Weather to Climatic modelling and forecasting
Keywords: Atmospheric Boundary Layer, Clouds - Convection, Precipitation
Creators: Janiga, Thorncroft
Publisher: African Monsoon Multidisciplinary Analyses (Ouagadougou, Burkina Faso)
Collection: Third International AMMA Conference

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Abstract
The phasing between convection and the flow associated with African easterly waves (AEWs) has been the subject of many investigations. It is generally accepted that cloud cover and rainfall frequency is greatest between the trough and northerly flow. The generation of convection is most frequent ahead of the trough while the termination of convection is most frequent in the ridge. In the Sahel a second genesis maxima is found in the mid to low-level southerlies. Previous studies have generally focused on the observation of these relationships and not on the physical causes. The relationship between mesoscale convective systems (MCSs) and AEWs is examined during the summers of 2004-2008. MCS characteristics are determined by automated objective cloud tracking of Meteosat infrared (IR) imagery. The preferred properties as well as genesis and lysis locations of MCSs are examined in the context of perturbations of shear, stability, lift, and moisture as a function of AEW phase. The environmental characteristics are determined using European Center for Medium Range Weather Forecasting (ECMWF) Interim Reanalysis over the period 2004-2008 and radiosonde data during the summer of 2006.
Added by: roussot