10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Comparison of Desert Aerosol Optical Characteristics of Ouarzazate (Morocco) and Sevilleta (New Mexico)
Abdelouahid Tahiri, MOHAMMED DIOURI, Jamal Barkani, Atmospheric Physic, LME, University of Oujda, Morocco
Abstract Number: 469 Working Group: Remote/Regional Atmospheric Aerosol
Abstract Sun-photometer columnar measurements of 2017, at Sevilleta (34.35N, 106.88W) and Ouarzazate (30.92°N, 6.91°W) AERONET sites allowed the determination of microphysical and optical characteristics of such different desert aerosol where both Saharan mineral dust (for Ouarzazate) and clear sky weather are observed depending to the season. The aerosol optical depth at 0,5 µm show high values with annual means of 0.30 ± 0.15 at Ouarzazate close to the Sahara and 0.08±0.03 at Sevilleta. The single scattering albedo monthly averages range from 0.45 to 0.90 with almost the same values for six months. The shape of the volume distributions of the particles are very different with very high amplitudes at Ouarzazate mostly for coarse mode (0.127±0.096 µm3/µm2), and with significant deviations of the respective median radii. All the results confirm the character of each site.
Despite the great differences in microphysical characteristics, the aerosol radiative forcing efficiency (month means) for visible wave seems having the same seasonal variation at bottom and at Top of the atmosphere. Near the Sahara or in the American continental desert, aerosols seem to act with the same tendency of radiative forcing, the surface albedo having a very important moderating role.