Characterization of the radiative impact of aerosols on CO₂ and energy fluxes in the Amazon deforestation arch using artificial neural networks
Abstract
In vegetation canopies with complex architectures, diffuse solar radiation can enhance carbon assimilation through photosynthesis because isotropic light is able to reach deeper layers of the canopy. Although this effect has been studied in the past decade, the mechanisms and impacts of this enhancement over South America remain poorly understood. Over the Amazon deforestation arch large amounts of aerosols are released into the atmosphere due to biomass burning, which provides an ideal scenario for further investigation of this phenomenon in the presence of canopies with complex architecture. In this paper, the relation of aerosol optical depth and surface fluxes of mass and energy are evaluated over three study sites with artificial neural networks and radiative transfer modeling. Results indicate a significant effect of the aerosol on the flux of carbon dioxide between the vegetation and the atmosphere, as well as on energy exchange, including that surface fluxes are sensitive to second-order radiative impacts of aerosols on temperature, humidity, and friction velocity. CO₂ exchanges increased in the presence of aerosol in up to 55 % in sites with complex canopy architecture. A decrease of approximately 12 % was observed for a site with shorter vegetation. Energy fluxes were negatively impacted by aerosols over all study sites.
Additional Information
© 2020 Author(s). This work is distributed under the Creative Commons Attribution 4.0 License. Published by Copernicus Publications on behalf of the European Geosciences Union. Received: 18 Feb 2019 – Discussion started: 07 Jun 2019 – Revised: 18 Jan 2020 – Accepted: 30 Jan 2020 – Published: 24 Mar 2020. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. California Institute of Technology. Government sponsorship acknowledged. © 2020. Code and data availability: Flux and aerosol data used in this study are available at https://doi.org/10.6084/m9.figshare.8239691.v1 (Braghiere et al., 2019). Supplement: The supplement related to this article is available online at: https://doi.org/10.5194/acp-20-3439-2020-supplement. Author contributions: RKB designed the study, conducted the analysis, and wrote the paper with help from all the other authors. MAY coordinated the intensive field campaign at Rebio Jaru in the dry season of 2007 and contributed to the writing of the paper. NMEdR developed the aerosols optical models. HRdR, JdSN, and ACdA coordinated the measurements and shared the flux data for Bananal Island, Sinop, and Rebio Jaru, respectively. The authors declare that they have no conflict of interest. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The authors would like to thank the staff from ICMBio at Rebio Jaru. Renata Aguiar, Federal University of Rondônia, Campus Ji Paraná, and the LBA local office for collecting and processing the flux data. Also, thanks to Frederico Trindade Teófilo and students of the LBA local office, as well as to Ruth Souza and other employees for the support during the field campaign. The authors thank three anonymous reviewers, whose comments improved the paper. This work was partly funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001, at the University of São Paulo, Brazil. Marcia Akemi Yamasoe acknowledges FAPESP (grant number 06-56550-5) and the National Council for Scientific and Technological Development – Brasil (CNPq) for grant number 313005/2018-4. Review statement: This paper was edited by Janne Rinne and reviewed by three anonymous referees.Attached Files
Published - acp-20-3439-2020_1_.pdf
Supplemental Material - acp-20-3439-2020-supplement.pdf
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Additional details
- Eprint ID
- 105260
- Resolver ID
- CaltechAUTHORS:20200904-094420091
- NASA/JPL/Caltech
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
- 06-56550-5
- Fundação de Amparo à Pesquisa do Estado de Sao Paulo (FAPESP)
- 313005/2018-4
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
- Created
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2020-09-08Created from EPrint's datestamp field
- Updated
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2023-06-02Created from EPrint's last_modified field