Potential impacts of wildfire on Southern Ocean clouds

Wildfires produce serious and long-lasting effects on weather and climate by large dust and aerosol emissions. However, its remote impacts on clouds over the Southern Ocean (SO) and polar regions remain unxplored. Based on ship observations conducted during MARCUS feild campaign from November, 2017 to March, 2018, a fire index (FI) is defined along the ship track by a lagrangian particle dispersion model (FLEXPART) combined with a daily high-resolution wildfire burned area dataset. Correaltions between this fire index and observed aerosol and CCN concentrations are analyzed to explore potential impacts of wildfire on SO clouds and its latitudinal variations. Our results show that the correlations between FI and aerosol concentrations are significant over the SO, which means the Autralia wildfire could affect the SO clouds reaching far to 70°S. The most significant positive correlations are found in the range of 40°S-55°S between FI and aerosol and CCN concentrations, with correlation coefficients of 0.65 and 0.88 respectively.