Estimation of the West African Monsoon variability through the analyses of the induced wave parameters
Résumé
Using local (rainfall data) and global satellite observations (atmospheric fields reanalysis, OLR data, satellite- observed brightness temperature data and cloud cluster data), the activity of convective equatorial waves revealed to be strongly coupled with the West african Monsoon (WaM) variability.
a previous study of wave activity in the West african area (Kafando et al., 2008), revealed that the signature of the monsoon is clearly observed on total energy density in the lower stratosphere (19-23km). the annual cycle and the climatology of wave total energy density showed that peaks of activity match the period of intense convection. in the present study, wave activity in relation with monsoon proxies (convection and precipitations) has been used to analyze the WaM interannual variability using nine years radiosonde observations, tropical rainfall Measuring Mission (trMM) data and Outgoing longwave radiation (Olr) data over several West african meteorological stations located in the latitudinal belt 4°n–20°n.