Light absorption enhancement (E-abs) of black carbon (BC) aerosol following atmospheric aging is one of the most challenging issues in the assessment of aerosol radiative forcing. BC E-abs is constrained by complex particle morphologies; however, large uncertainties continue to occur due to certain morphological parameters, including primary particle size. The values of E-abs during BC aging is quantified with diverse primary particle sizes using the superposition T-matrix method (STM). The results show that the uncertainty of absorption enhancement due to the primary particle size of fully aged BC particles ranges from similar to 10% to 20%, while the uncertainties arising from varied BC volume-equivalent size and fractal dimension are similar to 20-30% and similar to 8-12%, respectively. The optical properties of BC particles with volume-equivalent radii ranging from 50 to 70 nm were largely influenced (up to similar to 50%) by inappropriate assumptions regarding primary particle size. The specific assumptions of primary particle size in optical modeling plays an important role in constraining BC E-abs. (C) 2020 Elsevier Ltd. All rights reserved.

来源平台：JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER