Research Progress and Direction of Black Carbon Aerosol Metrology

Black carbon aerosol (BC) is an important component of atmospheric fine particulate matter, which have important impacts on air quality, climate change, aerosol radiative forcing, and human health. In recent years, the light absorption of BC has received increasing attention. There are various methods for measuring the absorption coefficient of BC, but significant differences between different methods are observed. It is urgent to establish a unified metrological system to ensure the accuracy, traceability, and comparability of BC light absorption measurement. This manuscript reviews the optical-based BC measurement methods currently used in China, including direct methods and indirect methods based on filters, as well as the standard materials, calibration algorithms, and application status in China. Finally, the challenges and future development directions of BC light absorption metrology in China are proposed.