Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models
<p>Biogenic volatile organic compounds (BVOCs) emitted from vegetation are oxidised in the atmosphere and can form aerosol particles either by contributing to new particle formation or by condensing onto existing aerosol particles. As the understanding of the importance of BVOCs for aerosol fo...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2020-07-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/20/8953/2020/acp-20-8953-2020.pdf |
| _version_ | 1819259774662868992 |
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| author | M. K. Sporre M. K. Sporre S. M. Blichner R. Schrödner I. H. H. Karset T. K. Berntsen T. K. Berntsen T. van Noije T. Bergman T. Bergman D. O'Donnell R. Makkonen R. Makkonen |
| author_facet | M. K. Sporre M. K. Sporre S. M. Blichner R. Schrödner I. H. H. Karset T. K. Berntsen T. K. Berntsen T. van Noije T. Bergman T. Bergman D. O'Donnell R. Makkonen R. Makkonen |
| author_sort | M. K. Sporre |
| collection | DOAJ |
| description | <p>Biogenic volatile organic compounds (BVOCs) emitted from vegetation are oxidised in the atmosphere and can form aerosol particles either by contributing to new particle formation or by condensing onto existing aerosol particles. As the understanding of the importance of BVOCs for aerosol formation has increased over the years, these processes have made their way into Earth system models (ESMs). In this study, sensitivity experiments are run with three different ESMs (the Norwegian Earth System Model (NorESM), EC-Earth and ECHAM) to investigate how the direct and indirect aerosol radiative effects are affected by changes in the formation of secondary organic aerosol (SOA) from BVOCs. In the first two sensitivity model experiments, the yields of SOA precursors from oxidation of BVOCs are changed by <span class="inline-formula">±50</span> %. For the third sensitivity test, the formed oxidation products do not participate in the formation of new particles but are only allowed to condense onto existing aerosols. In the last two sensitivity experiments, the emissions of BVOC compounds (isoprene and monoterpenes) are turned off, one at a time. The goal of the study is to investigate whether it is of importance to treat SOA formation processes correctly in the models rather than to evaluate the correctness of the current treatment in the models.</p>
<p>The results show that the impact on the direct radiative effect (DRE) is linked to the changes in the SOA production in the models, where more SOA leads to a stronger DRE and vice versa. However, the magnitude by which the DRE changes (maximally 0.15 W m<span class="inline-formula"><sup>−2</sup></span> globally averaged) in response to the SOA changes varies between the models, with EC-Earth displaying the largest changes. The results for the cloud radiative effects (CREs) are more complicated than for the DRE. The changes in CRE differ more among the ESMs, and for some sensitivity experiments they even have different signs. The most sensitive models are NorESM and EC-Earth, which have CRE changes of up to 0.82 W m<span class="inline-formula"><sup>−2</sup></span>. The varying responses in the different models are connected to where in the aerosol size distributions the changes in mass and number due to SOA formation occur, in combination with the aerosol number concentration levels in the models. We also find that interactive gas-phase chemistry as well as the new particle formation parameterisation has important implications for the DRE and CRE in some of the sensitivity experiments. The results from this study indicate that BVOC-SOA treatment in ESMs can have a substantial impact on the modelled climate but that the sensitivity varies greatly between the models. Since BVOC emissions have changed historically and will continue to change in the future, the spread in model results found in this study implies uncertainty into ESM estimates of aerosol forcing from land-use change and BVOC feedback strengths.</p> |
| first_indexed | 2024-12-23T19:15:21Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-23T19:15:21Z |
| publishDate | 2020-07-01 |
| publisher | Copernicus Publications |
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| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-490014845da343f091596bba38c4a3b42022-12-21T17:34:20ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242020-07-01208953897310.5194/acp-20-8953-2020Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system modelsM. K. Sporre0M. K. Sporre1S. M. Blichner2R. Schrödner3I. H. H. Karset4T. K. Berntsen5T. K. Berntsen6T. van Noije7T. Bergman8T. Bergman9D. O'Donnell10R. Makkonen11R. Makkonen12Department of Geosciences, University of Oslo, Postboks 1022 Blindern, 0315 Oslo, Norwaynow at: Department of Physics, Lund University, Box 118, 22100 Lund, SwedenDepartment of Geosciences, University of Oslo, Postboks 1022 Blindern, 0315 Oslo, NorwayInstitute for Tropospheric Research, Permoserstr. 15, 04318 Leipzig, GermanyDepartment of Geosciences, University of Oslo, Postboks 1022 Blindern, 0315 Oslo, NorwayDepartment of Geosciences, University of Oslo, Postboks 1022 Blindern, 0315 Oslo, NorwayCICERO Center for International Climate Research, Postboks 1129 Blindern, 0318 Oslo, NorwayRoyal Netherlands Meteorological Institute (KNMI), P.O. Box 201, 3730 AE De Bilt, the NetherlandsRoyal Netherlands Meteorological Institute (KNMI), P.O. Box 201, 3730 AE De Bilt, the NetherlandsClimate System Research, Finnish Meteorological Institute, P.O. Box 503, F00101, Helsinki, FinlandClimate System Research, Finnish Meteorological Institute, P.O. Box 503, F00101, Helsinki, FinlandClimate System Research, Finnish Meteorological Institute, P.O. Box 503, F00101, Helsinki, FinlandInstitute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, P.O. Box 64, F00014, Finland<p>Biogenic volatile organic compounds (BVOCs) emitted from vegetation are oxidised in the atmosphere and can form aerosol particles either by contributing to new particle formation or by condensing onto existing aerosol particles. As the understanding of the importance of BVOCs for aerosol formation has increased over the years, these processes have made their way into Earth system models (ESMs). In this study, sensitivity experiments are run with three different ESMs (the Norwegian Earth System Model (NorESM), EC-Earth and ECHAM) to investigate how the direct and indirect aerosol radiative effects are affected by changes in the formation of secondary organic aerosol (SOA) from BVOCs. In the first two sensitivity model experiments, the yields of SOA precursors from oxidation of BVOCs are changed by <span class="inline-formula">±50</span> %. For the third sensitivity test, the formed oxidation products do not participate in the formation of new particles but are only allowed to condense onto existing aerosols. In the last two sensitivity experiments, the emissions of BVOC compounds (isoprene and monoterpenes) are turned off, one at a time. The goal of the study is to investigate whether it is of importance to treat SOA formation processes correctly in the models rather than to evaluate the correctness of the current treatment in the models.</p> <p>The results show that the impact on the direct radiative effect (DRE) is linked to the changes in the SOA production in the models, where more SOA leads to a stronger DRE and vice versa. However, the magnitude by which the DRE changes (maximally 0.15 W m<span class="inline-formula"><sup>−2</sup></span> globally averaged) in response to the SOA changes varies between the models, with EC-Earth displaying the largest changes. The results for the cloud radiative effects (CREs) are more complicated than for the DRE. The changes in CRE differ more among the ESMs, and for some sensitivity experiments they even have different signs. The most sensitive models are NorESM and EC-Earth, which have CRE changes of up to 0.82 W m<span class="inline-formula"><sup>−2</sup></span>. The varying responses in the different models are connected to where in the aerosol size distributions the changes in mass and number due to SOA formation occur, in combination with the aerosol number concentration levels in the models. We also find that interactive gas-phase chemistry as well as the new particle formation parameterisation has important implications for the DRE and CRE in some of the sensitivity experiments. The results from this study indicate that BVOC-SOA treatment in ESMs can have a substantial impact on the modelled climate but that the sensitivity varies greatly between the models. Since BVOC emissions have changed historically and will continue to change in the future, the spread in model results found in this study implies uncertainty into ESM estimates of aerosol forcing from land-use change and BVOC feedback strengths.</p>https://www.atmos-chem-phys.net/20/8953/2020/acp-20-8953-2020.pdf |
| spellingShingle | M. K. Sporre M. K. Sporre S. M. Blichner R. Schrödner I. H. H. Karset T. K. Berntsen T. K. Berntsen T. van Noije T. Bergman T. Bergman D. O'Donnell R. Makkonen R. Makkonen Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models Atmospheric Chemistry and Physics |
| title | Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models |
| title_full | Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models |
| title_fullStr | Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models |
| title_full_unstemmed | Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models |
| title_short | Large difference in aerosol radiative effects from BVOC-SOA treatment in three Earth system models |
| title_sort | large difference in aerosol radiative effects from bvoc soa treatment in three earth system models |
| url | https://www.atmos-chem-phys.net/20/8953/2020/acp-20-8953-2020.pdf |
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