Significant Impacts of African Wildfire Aerosols on Mid- and High-Latitude Climates in the Northern Hemisphere

This study investigates the impacts of wildfire aerosols (primary organic carbon, black carbon and sulfate) on boreal winter climate. We found that the wildfire aerosols from equatorial Africa result in two mid-high latitude Rossby wave trains with one from subtropical Atlantic across North Europe to middle and east Siberia, and the other from Middle East across Pacific to the west coast of North America. The maximum positive height anomaly locates in North Europe, correlated with a greater than 2K surface warming. These Rossby wave trains are excited by the wildfire aerosols radiative heating in equatorial Africa through a Gill-type response. A further analysis unravels that the atmospheric heating is primarily caused by the absorption of black carbon, while the overall impact of other types of aerosols enhance it. The present study suggests that the light-absorbing aerosols in the tropics can have a profound impact on the mid-high latitude climate.