Simulation of Some Optical Phenomena Observed in the Chadian Atmosphere

This research focuses on simulating mirages, rainbows, and halos in the atmosphere of Chad. Simulation of the refractive index with temperature shows that the city of Moundou in the tropical climate and those of N’Djamena, Mongo, and Abeche in the Sahelian climate experience a strong alternation of superior and inferior mirages throughout the year. In contrast, in Faya-Largeau, which has a desert climate, both phenomena are observed throughout the year. The presence of abundant and moderate rainfall, respectively in Moundou in the tropical climate, and in Abeche, Mongo, and N’Djamena in the Sahelian climate, could give rise to the observation of rainbows. However, the absence of rainfall in the desert climate makes it almost impossible to observe rainbows in the city of Faya-Largeau.