Issue 2, 2022

Linking the chemical composition and optical properties of biomass burning aerosols in Amazonia

Abstract

Biomass burning emissions in Amazonia change the atmospheric composition and aerosol properties during the dry season. We investigated fine-mode aerosol chemical composition and optical properties with an intensive field experiment in the dry-to-wet season transition in 2018 in Southwestern Amazonia. Aerosol composition and physical properties were measured using ACSMs, aethalometers, nephelometers, SMPSs, and CPCs. PM1 mass concentrations showed a mean value of 12.4 ± 10.1 μg m−3. Organic matter was the major constituent of PM1, contributing more than 75%, whereas black carbon (BC) contributed ∼15%, and inorganics were less than 10%. The organic fraction of PM1 was apportioned by positive-matrix factorization (PMF), resolving 4 organic aerosol (OA) factors: two oxygenated OAs (OOA-1 and OOA-2), one hydrocarbon-like (HOA), and one biomass burning OA (BBOA). A low single scattering albedo (637 nm) of 0.77 ± 0.08 was observed, suggesting a significant absorption material. BC and brown carbon (BrC) contributions to the absorption coefficient (470 nm) were retrieved, and BrC corresponded, on average, to 20% of total absorption. The mass scattering (MSE) and absorption efficiencies (MAE) of PM1 particles were determined by multilinear regression (MLR), using the PMF factors as predictor variables. Overall, organic aerosols showed significant light absorption in the UV-vis wavelength range and strong spectral dependence indicating the presence of organic species that act as BrC, predominantly associated with biomass burning OAs. Our results emphasize the need for a better understanding of links between aerosol composition and optical properties, including the absorption spectra of BrC in the Amazon.

Graphical abstract: Linking the chemical composition and optical properties of biomass burning aerosols in Amazonia

Supplementary files

Transparent peer review

To support increased transparency, we offer authors the option to publish the peer review history alongside their article.

View this article’s peer review history

Article information

Article type
Paper
Submitted
05 iyl 2021
Accepted
06 dek 2021
First published
10 dek 2021
This article is Open Access
Creative Commons BY-NC license

Environ. Sci.: Atmos., 2022,2, 252-269

Linking the chemical composition and optical properties of biomass burning aerosols in Amazonia

M. Ponczek, M. A. Franco, S. Carbone, L. V. Rizzo, D. Monteiro dos Santos, F. G. Morais, A. Duarte, H. M. J. Barbosa and P. Artaxo, Environ. Sci.: Atmos., 2022, 2, 252 DOI: 10.1039/D1EA00055A

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements