Satellite observations of mineral dust interactions with West-African Monsoon clouds

摘要

An ew Bite mporal Min eral Du st I ndex (BMDI) from MS G in frared ch annels w as u sed to examine th e in fiuence of min eral d ust on con vective clouds and t he monsoon in t he We st-African Sahe 1 region.Analysing BMDI and contemporary cloud parameter and p recipitation retr ievals s hows th at ob servation density distributions of cloud properties such as cloud cover an d Cl oud Top Te mperature (CTT) are changed significantly in the presence of d ust. Besides the s trong c ontrast of cl oud p roperties and precipitation bet ween dus ty and dust-free scenes, cloud lifeti mes are in creased d ue to p recipitation suppression for h igher dust loads, which can be seen in increasing cloud cover, d ecreasing CTT and lower rainfall averages. As other non-dust aerosols are p art of background conditions i n the statistical analy sis, the res ults s trongly in dicate to th en ecessity for different treatment of aerosol species in aerosol-cloud interaction studies.