Impact of near-term climate forcing on the Arctic Oscillation

Near-term climate forcers (NTCFs), including aerosols and chemically reactive gases, influence both climate and air quality. However, the impact of NTCFs on internal climate variability is unclear. This study investigates how reductions in NTCFs affect Arctic Oscillation (AO) in the near future, using the Aerosol and Chemistry Model Intercomparison Project. Reduced NTCFs increase the occurrence of the positive AO in the near-future period. We suggest that reduced NTCFs modulate the atmospheric mean-state toward a more positive AO-like structure by increasing the meridional temperature gradient, thereby shifting the zonal-mean zonal wind poleward. The frequent occurrence of a positive AO further contributes to enhanced surface warming across the Northern Hemisphere in the near future. Therefore, a comprehensive understanding of the diverse impacts of NTCFs on internal climate variability is essential for effectively managing future NTCFs emissions.