The impact of Sulphate Aerosol Geoengineering on Tropical Cyclones

Sulphate Aerosol Geoengineering (SAG) works by increasing reflection of incoming solar radiation in the stratosphere and is a proposed way to mitigate global warming effects. Careful consideration of this method must include its impact on extreme weather, such as tropical cyclones. However, little to no SAG simulations exist at a resolution that is sufficient to explicitly model tropical cyclones due to the high computational cost of stratospheric chemistry. Recent work has shown a simple yet effective way to dynamically scale the stratospheric aerosol field from pre-existing SAG simulations to control global temperature, reducing the need for active stratospheric chemistry. Applying this method, we force a delayed SAG scenario in global fully-coupled CESM1 simulations with an atmosphere (ocean) grid resolution of 0.25 (0.1) degrees and compare it to a high forcing scenario. We present an examination of the impact of SAG on intensity, precipitation and track density of tropical cyclones.