Laboratory synthesis and characterization of wildfire-like dark brown carbon aerosols

Le résumé fourni par la source

Wildfire emissions consist of abundant dark brown carbon (d-BrC), which strongly absorbs across the ultraviolet (UV), visible, and near-infrared (NIR) ranges. This type of BrC has been identified in laboratory studies and was recently observed in forest fires, underscoring the importance of reevaluating the role of BrC aerosol particles in current climate models. This study aims to synthesize d-BrC particles in a laboratory setting and characterize their physicochemical properties, primarily focusing on their optical properties. D-BrC aerosol particles were generated by aerosolizing tar derived from wood pyrolysis and outgassing high-volatility organic compounds. The imaginary part of the refractive indices (k) of the generated d-BrC aerosol particles range from 0.13 to 0.41 at 550 nm, corresponding to heat shock temperatures between 250 and 400 °C. The k values at near-infrared wavelengths (750–1000 nm) range from 0.06 to 0.30. Volatility distribution and chemical functional group analyses confirmed the compositional similarity to wildfire-emitted d-BrC, which consists of low- and extremely low-volatility organic compounds (ELVOCs).Copyright © 2025 American Association for Aerosol Research

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.