The Respective Roles of Wind Speed and Green Vegetation in Controlling Sahelian Dust Emission During the Wet Season. Issue 22 (14th November 2020)

• Record Type: Journal Article
• Authors: Bergametti, G.; Marticorena, B.; Rajot, J. L.; Siour, G.; Féron, A.; Gaimoz, C.; Coman, A.; Chatenet, B.; Coulibaly, M.; Maman, A.; Koné, I.; Zakou, A.
• Is Part Of: Geophysical research letters. Volume 47:Issue 22(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-14
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL089761
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Based on 10 years of continuous measurements of wind speed, rainfall, and PM10 concentrations (i.e., concentrations of the particulate matter having a diameter lower than 10 μm) performed in two Sahelian stations, we examine how wind speed and vegetation interact during the wet season to control the dust concentration when it is due to local dust emissions. The results clearly show that the frequency of the high wind speeds is higher at the beginning of the wet season and is the main driver of the seasonal dust emission. During the second part of the wet season, the frequency of high wind speeds is much lower and, in addition, their efficiency for wind erosion and dust emission is strongly affected by the vegetation whose growth reduces progressively PM10 concentrations up to 80%. Key Points: Between May and September, the decrease of the high wind speeds is the main reason for the decrease of PM10 in the Central Sahel During the growing period (June to September), the green vegetation progressively reduces dust emission efficiency in the Sahel For identical wind speeds, vegetation cover characterized by NDVI higher than 0.26 reduces PM10 concentrations up to 80%