Effects of Volcanic Aerosols on the Genesis of Tropical Cyclone Wukong (2018).

The short‐range impacts of volcanic aerosols from the eruption of the Kilauea volcano on the genesis of tropical cyclone (TC) Wukong in 2018 are investigated by numerical simulations, as distinct from the studies on the aerosol climate effects. The aerosol−radiation and aerosol−cloud effects are isolated through sensitivity experiments. For the aerosol−radiation effect, the radiative cooling at the low levels and heating above by aerosols southeast of Wukong's periphery induce stable sinking and decrease latent heating in the environment far from the storm center. Therefore, the sea‐level pressure increases there, enhancing low‐level radial inflow to the storm, inner‐core convection and the release of latent heat, which is conducive to TC genesis. For the aerosol−cloud effect, volcanic aerosols in storm circulation can be converted into cloud condensation nuclei, invigorating inner‐core convection, and subsequently favoring TC genesis. However, the nonlinear effect resulting from the interaction between aerosol−radiation and aerosol−cloud effects is not conducive to TC genesis, because it weakens the aerosol−cloud effect through the deposition of aerosols and also limits the aerosol−radiation effect through the increasing of peripheral convection. Plain Language Summary: The role of sulfate aerosols released by volcanic eruptions in climatological tropical cyclone (TC) activities over different basins or hemispheres remains uncertain. These aerosols, composed of either solid or liquid particles, not only change the heating or cooling of atmosphere by scattering and absorbing sunlight, but also participate in cloud formation and evolution by conversion into nuclei of cloud droplets. Impacts of aerosol−radiation and aerosol−cloud interaction on a TC formation process during a volcanic eruption still lacks of detailed study for real cases. We investigate whether these effects of aerosols from the Kilauea volcanic eruption were beneficial or not to the formation of TC Wukong in 2018. The aerosol−radiation effect enhances cooling at the low levels of Wukong's environment and increases the sea‐level pressure there, which drives air to flow inward and is beneficial to TC genesis. On the other hand, lots of aerosols ingested into the storm invigorates the convection near the storm center, is also helpful. Instead, the interaction between the above two effects offset partly their own positive contributions to TC genesis. Our findings suggest that considering the interaction of volcanic aerosol−cloud−radiation is necessary to improve our understanding and prediction of TC activities. Key Points: Enhanced radiative cooling at low layer of Wukong's periphery induced by aerosols from Kilauea volcanic eruption advanced its genesisMicrophysical effect of the aerosols partly entering into Wukong's inner core invigorated convection so as to favor its genesisThe nonlinear interaction between the aerosol−radiation and the aerosol−cloud effects contributed negatively to Wukong's genesis [ABSTRACT FROM AUTHOR]