Large dust absorption of infrared radiation over Afro-Asian regions: evidence for anthropogenic impact

Abstract

There is a large uncertainty in the estimation of dust radiative forcing due to the lack of adequate data about complex spatial and temporal pattern of the radiative properties of dust. Here, we examine the temporal and spatial variability of dust absorption in the thermal infrared over the Afro-Asian regions using satellite data. Large dust absorption (nearly double compared to that of pure dust) was observed in regions with large anthropogenic influence, possibly due to deposition of black carbon on dust particles. While most of the recent estimates of global mean dust radiative forcing predicted net cooling, our studies indicate that there could be large heating due to dust over vast Afro-Asian regions. It appears that large dust heating is due to its interaction with anthropogenic black carbon.