Mineral aerosol and cloud interactions

Interactions between aerosols and clouds are the subject of considerable scientific research, due to the importance of clouds in controlling climate. Here we consider the relationship between mineral aerosols and cloud properties over North Africa and the North Atlantic using monthly mean observations of mineral aerosols and clouds over 16 years. The results of this study are consistent with mineral aerosols suppressing precipitation in thin low altitude clouds and changing cloud amounts in ice phase clouds. Because we cannot eliminate either spurious correlations, or that the cloud and dust changes are both driven by the same meteorological conditions, we cannot provide definitive conclusions. However, these results suggest complicated and tantalizing feedbacks between mineral aerosols and climate. This question becomes crucial as we note that mineral aerosols from North Africa have increased substantially since the 1960s for reasons which are poorly understood but that may be linked to human activity.