A review of quantification methods for light absorption enhancement of black carbon aerosol

Yao Kong; Guorui Zhi; Wenjing Jin; Yuzhe Zhang; Yi Shen; Zhengying Li; Jianzhong Sun; Yanjun Ren

doi:10.1016/j.scitotenv.2024.171539

A review of quantification methods for light absorption enhancement of black carbon aerosol

Sci Total Environ. 2024 May 10:924:171539. doi: 10.1016/j.scitotenv.2024.171539. Epub 2024 Mar 9.

Authors

Yao Kong¹, Guorui Zhi², Wenjing Jin¹, Yuzhe Zhang³, Yi Shen¹, Zhengying Li⁴, Jianzhong Sun⁵, Yanjun Ren¹

Affiliations

¹ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
² State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: zhigr@craes.org.cn.
³ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: yzzhang943@foxmail.com.
⁴ Beijing Municipal Ecological and Environmental Monitoring Center, Beijing 100048, China.
⁵ School of Physical Education, Chizhou University, Chizhou, Anhui 247000, China.

PMID: 38462012
DOI: 10.1016/j.scitotenv.2024.171539

Abstract

Black carbon (BC) is a distinct type of carbonaceous aerosol that has a significant impact on the environment, human health, and climate. A non-BC material coating on BC can alter the mixing state of the BC particles, which considerably enhances the mass absorption efficiency of BC by directing more energy toward the BC cores (lensing effect). A lot of methods have been reported for quantifying the enhancement factor (E_abs), with diverse results. However, to the best of our knowledge, a comprehensive review specific to the quantification methods for E_abs has not been systematically performed, which is unfavorable for the evaluation of obtained results and subsequent radiative forcing. In this review, quantification methods are divided into two broad categories, direct and indirect, depending on whether experimental removal of the coating layer from an aged carbonaceous particle is required. The direct methods described include thermal peeling, solvent dissolution, and optical virtual exfoliation, while the indirect methods include intercept-linear regression fitting, minimum R squared, numerical simulation, and empirical value. We summarized the principles, procedures, virtues, and limitations of the major E_abs quantification methods and analyzed the current problems in the determination of E_abs. We pointed out what breakthroughs are needed to improve or innovate E_abs quantification methods, particularly regarding the need to avoid the influence of brown carbon, develop a broadband E_abs quantification scheme, quantify the E_abs values for the emissions of low-efficiency combustions, measure the E_abs of particles in a high-humidity environment, design a real-time monitor of E_abs by a proper combination of mature techniques, and make more use of artificial intelligence for better E_abs quantification. This review deepens the understanding of E_abs quantification methods and benefits the estimation of the contribution of BC to radiative forcing using climate models.

Keywords: Black carbon; Light absorption enhancement; Quantification method; Review.

Publication types

Review