Features of the low–level temperature inversions at Abidjan upper-air station Ivory Coast

Abstract

This work examine the characteristics of the low-level (surface-based and elevated) temperature inversions above Abidjan (Ivory Coast) to a pressure level of 700 hPa by using daily (midnight and midday) upper-air meteorological data over the period 2007-2015. The monthly and vertical variations of inversions, characterized by vertical gradients of temperature (strength), potential temperature, dew point temperature, depth, and inversion index, were studied. On the monthly basis, it is worth noting that elevated inversions were more common throughout the year than surface-based inversions. The frequency peak of elevated inversions was found in summer months whereas the peak of surface-based was in winter. Moreover, for the both midday and midnight soundings, the strongest inversions occurred in summer but a relative maximum strength of inversions was evidently shown in winter. The vertical variations of the characteristics of inversions helped us to highlight the types of inversions and the physical processes associated. The role of radiation inversions for air pollution dispersion was also discussed.