Reddington, CL, Spracklen, DV, Artaxo, P et al. (3 more authors) (2016) Analysis of particulate emissions from tropical biomass burning using a global aerosol model and long-term surface observations. Atmospheric Chemistry and Physics, 16 (17). pp. 11083-11106. ISSN 1680-7316
Abstract
We use the GLOMAP global aerosol model evaluated against observations of surface particulate matter (PM₂⋅₅) and aerosol optical depth (AOD) to better understand the impacts of biomass burning on tropical aerosol over the period 2003 to 2011. Previous studies report a large underestimation of AOD over regions impacted by tropical biomass burning, scaling particulate emissions from fire by up to a factor of 6 to enable the models to simulate observed AOD. To explore the uncertainty in emissions we use three satellite-derived fire emission datasets (GFED3, GFAS1 and FINN1). In these datasets the tropics account for 66-84% of global particulate emissions from fire. With all emission datasets GLOMAP underestimates dry season PM₂⋅₅ concentrations in regions of high fire activity in South America and underestimates AOD over South America, Africa and Southeast Asia. When we assume an upper estimate of aerosol hygroscopicity, underestimation of AOD over tropical regions impacted by biomass burning is reduced relative to previous studies. Where coincident observations of surface PM₂⋅₅ and AOD are available we find a greater model underestimation of AOD than PM₂⋅₅, even when we assume an upper estimate of aerosol hygroscopicity. Increasing particulate emissions to improve simulation of AOD can therefore lead to overestimation of surface PM₂⋅₅ concentrations. We find that scaling FINN1 emissions by a factor of 1.5 prevents underestimation of AOD and surface PM₂⋅₅ in most tropical locations except Africa. GFAS1 requires emission scaling factor of 3.4 in most locations with the exception of equatorial Asia where a scaling factor of 1.5 is adequate. Scaling GFED3 emissions by a factor of 1.5 is sufficient in active deforestation regions of South America and equatorial Asia, but a larger scaling factor is required elsewhere. The model with GFED3 emissions poorly simulates observed seasonal variability in surface PM₂⋅₅ and AOD in regions where small fires dominate, providing independent evidence that GFED3 underestimates particulate emissions from small fires. Seasonal variability in both PM₂⋅₅ and AOD is better simulated by the model using FINN1 emissions. Detailed observations of aerosol properties over biomass burning regions are required to better constrain particulate emissions from fires.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Oct 2016 16:03 |
Last Modified: | 05 Oct 2017 16:07 |
Published Version: | https://doi.org/10.5194/acp-16-11083-2016 |
Status: | Published |
Publisher: | European Geosciences Union |
Identification Number: | 10.5194/acp-16-11083-2016 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:105846 |