Particles in the atmosphere that are a result of human activities lowered the frequency of tropical storms over the Atlantic Ocean in the twentieth century, reports a paper published online this week in Nature Geoscience. The findings suggest that variations in atmospheric aerosol levels drove historical variations in storm activity.
Nick Dunstone and colleagues used climate model simulations to assess the effect of aerosol emissions on tropical storms over the Atlantic Ocean and show that aerosols suppressed the frequency of these storms over much of the twentieth century. They suggest that the suppression results from an aerosol-induced alteration of temperatures at the sea surface.
In an accompanying News and Views, Johannes Quaas says they “provide convincing evidence for a significant influence of anthropogenic aerosols on tropical storm activity over the North Atlantic in the twentieth century.”