Rapid warming in the Arctic has a huge impact on the global environment. Atmospheric brown carbon (BrC) is one of the least understood and uncertain warming agents due to a lack of observations. This study performed direct observations of atmospheric BrC and quantified its light-absorbing properties during a two-month circum-Arctic cruise in the summer of 2017. 

Through observation-constrained modeling, the research shows that BrC, mainly originated from biomass burning in the mid-to-high latitudes of the Northern Hemisphere (~60%), can be a strong warming agent in the Arctic region, especially in the summer, with an average radiative forcing of ~90 mW m^–2 (~30% relative to black carbon).

As climate change is projected to increase the frequency, intensity and spread of wildfires will increase at mid and high latitudes in the Northern Hemisphere in the future. The increase in biomass burning will release more brown and black carbon aerosols and further accelerate warming in the Arctic, creating a positive feedback effect. The contribution of brown carbon aerosols to Arctic warming is expected to be more important in the future. The results indicate that strengthening effective management of northern hemisphere high latitude wildfires will play an important role in mitigating arctic and global climate change.

This study has been published on One Earth. Dr. Siyao Yue and Prof. Jialei Zhu are co-first authors. Prof. Pingqing Fu and Dr. Yafang Cheng in MPI-Chemistry are co-corresponding authors.

Please find the full text with the link: https://doi.org/10.1016/j.oneear.2022.02.006

By School of Earth System Science

Editor: Sun Xiaofang