TITLE:
Vertical Profile Comparison of Aerosol and Cloud Optical Properties in Dominated Dust and Smoke Regions over Africa Based on Space-Based Lidar
AUTHORS:
Didier Ntwali, Getachew Dubache, Faustin Katchele Ogou
KEYWORDS:
Vertical Profile, Dust Aerosols, Smoke Aerosols, Clouds, Africa, Lidar Climatology of Vertical Aerosol Structure for Space-Based Lidar Simulation Studies (LIVAS)
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.12 No.3,
July
12,
2022
ABSTRACT: This
study evaluates the vertical profiles of aerosol and cloud optical properties
in 40 dominated dust and smoke regions in Western-Northern Africa (WNA) and
Central-Southern Africa (CSA), respectively, from the surface to 10km and from
2008 to 2011 based on LIVAS (LIdar climatology of Vertical Aerosol Structure
for space-based lidar simulation studies). Aerosol extinction (AE), aerosol
backscatter (AB), and aerosol depolarization (AD) generally increase from the
surface to 1.2 km and decrease from 1.2 km to the upper layers in both WNA and
CSA. AE and AB in CSA (maximum of 0.13 km-1, 0.14 km-1,
0.0021 km-1‧sr-1, 0.0033 km-1‧sr-1)
are higher than in WNA (maximum of 0.07 km-1, 0.08 km-1,
0.0017 km-1‧sr-1, 0.0015 km-1‧sr-1)
at 532 and 1064 nm respectively. AD in WNA (maximum of 0.25) is significantly
higher than in CSA (maximum of 0.05). There is a smooth change with the height
of cloud extinction and backscatter in WNA and CSA, while there is a remarkable
increase of cloud depolarization with height, whereby it is high in CSA and low
in WNA due to high and low fraction of cirrus respectively. Altocumulus has the
highest extinction in NA (0.0139 km-1), CA (0.058 km-1),
WA (0.013 km-1), while low overcast transparent (0.76 km-1)
below 1 km in SA. The major findings of this study may contribute to the
improvement of our understanding of aerosol-cloud interaction studies in
dominated dust and smoke aerosol regions.