Climatological Analysis of Aerosols Optical Properties by Airborne Sensors and in Situ Measurements in West Africa: Case of the Sahelian Zone

作     者：Nébon Bado Adama Ouédraogo Hassime Guengané Thierry Sikoudouin Maurice Ky Serge Dimitri Bazyomo Bruno Korgo Mamadou Simina Dramé Saidou Moustapha Sall Florent P. Kieno Dieudonné Joseph Bathiebo 

作者机构：Laboratoire d’Energies Thermiques Renouvelables (L.E.T.RE) Université Joseph Ki Zerbo Ouaga Burkina Faso Laboratoire de Physique de l’Atmosphère et de l’Océan Siméon Fongang Université Cheikh Anta Diop Dakar-Fann Sénégal Centre Universitaire Polytechnique de Kaya (CUP-K) Kaya Burkina Faso Institute of Mathematics and Physical Sciences University of Abomey-Calavi Porto-Novo Benin 

出 版 物：《Open Journal of Air Pollution》 (大气污染开放期刊（英文）)

年 卷 期：2019年第8卷第4期

页      面：118-135页

学科分类：07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 

主　　题：West-Africa Aerosols Airborne Sensors Aeronet MERRA Model 

摘      要：This paper deals with the climatology of aerosols in West Africa based on satellite and in situ measurements between 2001 and 2016 and covers four sites in the Sahelian zone. There are indeed Banizoumbou (13.541°N, 02.665°E), Cinzana (13.278°N, 05.934°W), Dakar (14.394°N, 16.959°W) and Ouagadougou (12.20°N, 1.40°W) located respectively in Niger, Mali, Senegal and Burkina Faso. Thus, an intercomparison between the satellite observations and the in situ measurements shows a good correlation between MODIS and AERONET with a correlation coefficient R = 0.86 at Cinzana, R = 0.85 at Banizounbou, R = 0.84 at Ouagadougou and a low correlation coefficient R = 0.66 calculated on the Dakar site. Like MODIS, SeaWiFS shows a very good correspondence with measurements of the ground photometer especially for Banizoumbou (R = 0.89), Cinzana (R = 0.88) and Dakar (R = 0.75) followed by a low correlation coefficient calculated on the Ouagadougou site (R = 0.64). The performance of these airborne sensors is also corroborated by the calculation of root mean square error (RMSE) and the mean absolute error (MAE). Following this validation, a climatological analysis based on aerosol optical depth (AOD) shows the seasonality of aerosols in West Africa strongly influenced by the climate dynamics illustrated by the MERRA model reanalysis. This seasonal spatial distribution of aerosols justifies the temporal variability of the particles observed at the different sites in the Sahel. In addition, a combined analysis of AOD and Angstrom coefficient indicates the aerosol period in the Sahel in spring (March-April-May) and summer (June-July-August). However, these aerosols are strongly dominated by desert dust whose main sources are located north in the Sahara and Sahel.