This study led by Marjan Savadkoohi evaluates the Absorption Ångström Exponent (AAE) approach for equivalent black carbon (eBC) source apportionment, addressing its strengths and limitations when distinguishing between liquid and solid fuels sources. Using a comprehensive multi-site dataset across Europe, this study recommend an optimized methodology for determining site-specific AAE values, enhancing the accuracy of eBC source attribution across diverse environments.

Key Findings:

•  Site-specific AAE calibration significantly improves eBC source differentiation.
•  Constant AAE values lead to misclassification, especially in regions with high brown carbon (BrC) contributions.
• The integration of chemical tracers and multi-wavelength absorption data is essential for refining optical source apportionment.

This research provides valuable insights for air quality monitoring, emission regulation, and climate modeling.

Check out the full article here: https://doi.org/10.1016/j.atmosenv.2025.121121