Unified theoretical framework for black carbon mixing state allows greater accuracy of climate effect estimation

The authors build a unified theoretical framework of black carbon mixing state and find a universal law, applicable in most climate/atmospheric chemistry models, which can greatly increase accuracy of black carbon climate effect estimation. Black carbon (BC) plays an important role in the climate system because of its strong warming effect, yet the magnitude of this effect is highly uncertain owing to the complex mixing state of aerosols. Here we build a unified theoretical framework to describe BC's mixing states, linking dynamic processes to BC coating thickness distribution, and show its self-similarity for sites in diverse environments. The size distribution of BC-containing particles is found to follow a universal law and is independent of BC core size. A new mixing state module is established based on this finding and successfully applied in global and regional models, which increases the accuracy of aerosol climate effect estimations. Our theoretical framework links observations with model simulations in both mixing state description and light absorption quantification.

Automated summary

The authors propose a unified theoretical framework for describing the mixing state of black carbon, and discover a universal law that can greatly improve the accuracy of estimating the climate effect of black carbon in most climate/atmospheric chemistry models.