Quantifying the impact of unresolved particle properties on light absorption by carbonaceous aerosol
Abstract
Radiative absorption by carbonaceous aerosol depends on internal mixing within individual particles, but the composition and morphology of aerosol particles is necessarily approximated in large-scale atmospheric models. In this study, we introduce a parameterization that predicts the absorption coefficient of particle populations containing black and brown carbon, while also representing uncertainty in absorption from unresolved particle properties. The parameterization is a Bayesian linear regression model that was trained using ensembles of simulations with the particle-resolved model PartMC-MOSAIC. PartMC-MOSAIC is the only aerosol scheme that tracks per-particle composition of many thousands of particles in evolving aerosol populations, but this detailed model is computationally expensive. As an alternative to resolving per-particle properties in large-scale models, this study presents a hierarchical modeling framework for approximating key processes, such as aerosol water uptake and the impact of inter- and intra-particle mixing, in terms of variables that many large-scale models already carry.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA243...05F
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES;
- 3337 Global climate models;
- ATMOSPHERIC PROCESSES;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES