[A-CG34] Climate Variability and Predictability on Subseasonal to Multidecadal Timescales

[ACG34-03] Substantial Global Influence of Anthropogenic Aerosols on Tropical Cyclones over the Last 40 Years

*Hiroyuki Murakami¹ (1.Geophysical Fluid Dynamics Laboratory/University Corporation for Atmospheric Research)

Keywords:Anthropogenic aerosols, Tropical cyclone, Climate modeling

Several studies to date have demonstrated a substantial impact of aerosols on regional tropical cyclone (TC) activity. However, it is not yet clear how changes in anthropogenic aerosols, such as sulfate, have altered and will change global TC activity. Indeed, over the last 40 years, anthropogenic aerosols have been significantly decreasing over Europe and the United States owing to pollution control measures, whereas they have increased in South and East Asia because of the economic and industrial growth in these regions. In this study, we applied climate model simulations by imposing the changes in global anthropogenic aerosols over the last 40 years and uncovered a substantial global impact of anthropogenic aerosols on the spatial distributions of TCs. Specifically, the decreases in aerosols over Europe and the United States have contributed to significant decreases in TCs over the Southern Hemisphere as well as increases in TCs over the North Atlantic, whereas the increases in aerosols in South and East Asia have exerted substantial decreases in TCs over the western North Pacific. These global-scale simulated changes in TCs are a result of the global changes in large-scale circulations imposed by the changes in anthropogenic aerosols. These results highlight that how we control emissions of anthrophonic aerosols in the future, as well as greenhouse gases, will exert a substantial impact on the world’s TC activity.