학술논문

Vertical structure of aerosols and water vapor over West Africa during the African monsoon dry season
Document Type
article
Source
Atmospheric Chemistry and Physics, Vol 9, Iss 20, Pp 8017-8038 (2009)
Subject
Physics
QC1-999
Chemistry
QD1-999
Language
English
ISSN
1680-7316
1680-7324
Abstract
We present observations of tropospheric aerosol and water vapor transport over West Africa and the associated meteorological conditions during the AMMA SOP-0 dry season experiment, which was conducted in West Africa in January–February 2006. This study combines data from ultra-light aircraft (ULA)-based lidar, airborne in-situ aerosol and gas measurements, standard meteorological measurements, satellite-based aerosol measurements, airmass trajectories, and radiosonde measurements. At Niamey (13.5° N, 2.2° E) the prevailing surface wind (i.e. Harmattan) was from the northeast bringing dry dusty air from the Sahara desert. High concentrations of mineral dust aerosol were typically observed from the surface to 1.5 or 2 km associated with the Saharan airmasses. At higher altitudes the prevailing wind veered to the south or southeast bringing relatively warm and humid airmasses from the biomass burning regions to the Sahel (LAE)BER): 0.026~0.028 sr−1) at low levels (LAE: 0.6~1.1, BER: 0.015~0.018 sr−1) between 2 and 5 km. CALIOP data indicated that these distinct continental dust and biomass burning aerosol layers likely mixed as they advected further south over the tropical Atlantic Ocean, as indicated an intermediate values of δ (10~17%), LAE (0.16~0.18) and BER (0.0021~0.0022 sr−1).