Satellite Detection of Saharan Dust: Optimized Imaging during Nighttime

Abstract

The data of the ECLATS experiment (at Niamey, 1980) are used to study the daily variations of the sensitivity of ground temperature to atmospheric dustiness. In the presence of dust, ground temperature is lower during daytime and higher than normal during nighttime. During night, the influence of dust on ground temperature prevails over other factors. The sensitivity of temperature to dustiness is evaluated and used jointly with ECLATS aircraft soundings to assess the impact of atmospheric dust on the radiance measured by the METEOSAT-I thermal infrared sensor. The results obtained demonstrate the ability of METEOSAT to detect dust clouds during nighttime. A method of optimized imaging is described and applied to a case study.