Sensitivity of low-level clouds and precipitation to anthropogenic aerosol emission in southern West Africa: a DACCIWA case study - Archive ouverte HAL Access content directly
Journal Articles Atmospheric Chemistry and Physics Year : 2022

Sensitivity of low-level clouds and precipitation to anthropogenic aerosol emission in southern West Africa: a DACCIWA case study

(1, 2, 3) , (1) , (4) , (5) , (5) , (6) , (7) , (8) , (9) , (10) , (11, 12) , (5) , (13) , (9) , (14) , (15) , (11, 12)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Cyrille Flamant
Régis Dupuy
Fabienne Lohou

Abstract

During the West African summer monsoon, pollutants emitted in urbanized coastal areas modify cloud cover and precipitation patterns. The Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa (DACCIWA) field campaign provided numerous aircraft-based and ground-based observations, which are used here to evaluate two experiments made with the coupled WRF–CHIMERE model, integrating both the direct and indirect aerosol effect on meteorology. During one well-documented week (1–7 July 2016), the impacts of anthropogenic aerosols on the diurnal cycle of low-level clouds and precipitation are analyzed in detail using high and moderate intensity of anthropogenic emissions in the experiments. Over the continent and close to major anthropogenic emission sources, the breakup time of low-level clouds is delayed by 1 hour, and the daily precipitation rate decreased by 7.5 % with the enhanced anthropogenic emission experiment (with high aerosol load). Despite the small modifications on daily average of low-level cloud cover (+2.6 %) with high aerosol load compared to moderate, there is an increase by more than 20 % from 14:00 to 22:00 UTC on hourly aver- age. Moreover, modifications of the modeled low-level cloud and precipitation rate occur far from the major anthropogenic emission sources, to the south over the ocean and to the north up to 11◦ N. The present study adds evidence to recent findings that enhanced pollution levels in West Africa may reduce precipitation.
Fichier principal
Vignette du fichier
acp-22-3251-2022.pdf (13.52 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03198739 , version 1 (15-04-2021)
insu-03198739 , version 2 (11-03-2022)

Licence

Attribution - NonCommercial - CC BY 4.0

Identifiers

Cite

Adrien Deroubaix, Laurent Menut, Cyrille Flamant, Peter Knippertz, Andreas H. Fink, et al.. Sensitivity of low-level clouds and precipitation to anthropogenic aerosol emission in southern West Africa: a DACCIWA case study. Atmospheric Chemistry and Physics, 2022, 22 (5), pp.3251-3273. ⟨10.5194/acp-22-3251-2022⟩. ⟨insu-03198739v2⟩
222 View
49 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More