Possible Aerosol Impacts on Tropical Cyclones

We implement a diagnostic treatment of aerosol-cloud interactions in a global 25-km hurricane seasonal forecast model, and use the modified model to study the atmospheric-only effect of anthropogenic aerosols on tropical cyclones (TC). It is found that aerosols can alter the TC counts and tracks significantly, especially on the regional scale. The magnitudes are comparable to the atmospheric-only effect of greenhouse gases. A series of sensitivity experiments are performed to explore the underlying physical mechanisms. The sensitivity to the vertical distributions of aerosols is also discussed.