Long term measurements of aerosol optical properties at a primary forest site in Amazonia
Autor(a) principal: | |
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Data de Publicação: | 2013 |
Outros Autores: | , , , , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNIFESP |
Texto Completo: | http://dx.doi.org/10.5194/acp-13-2391-2013 http://repositorio.unifesp.br/handle/11600/35755 |
Resumo: | A long term experiment was conducted in a primary forest area in Amazonia, with continuous in-situ measurements of aerosol optical properties between February 2008 and April 2011, comprising, to our knowledge, the longest database ever in the Amazon Basin. Two major classes of aerosol particles, with significantly different optical properties were identified: coarse mode predominant biogenic aerosols in the wet season (January-June), naturally released by the forest metabolism, and fine mode dominated biomass burning aerosols in the dry season (July-December), transported from regional fires. Dry particle median scattering coefficients at the wavelength of 550 nm increased from 6.3 Mm(-1) to 22 Mm(-1), whereas absorption at 637 nm increased from 0.5 Mm(-1) to 2.8 Mm(-1) from wet to dry season. Most of the scattering in the dry season was attributed to the predominance of fine mode (PM2) particles (40-80% of PM10 mass), while the enhanced absorption coefficients are attributed to the presence of light absorbing aerosols from biomass burning. As both scattering and absorption increased in the dry season, the single scattering albedo (SSA) did not show a significant seasonal variability, in average 0.86 +/- 0.08 at 637 nm for dry aerosols. Measured particle optical properties were used to estimate the aerosol forcing efficiency at the top of the atmosphere. Results indicate that in this primary forest site the radiative balance was dominated by the cloud cover, particularly in the wet season. Due to the high cloud fractions, the aerosol forcing efficiency absolute values were below -3.5 Wm(-2) in 70% of the wet season days and in 46% of the dry season days. Besides the seasonal variation, the influence of out-of-Basin aerosol sources was observed occasionally. Periods of influence of the Manaus urban plume were detected, characterized by a consistent increase on particle scattering (factor 2.5) and absorption coefficients (factor 5). Episodes of biomass burning and mineral dust particles advected from Africa were observed between January and April, characterized by enhanced concentrations of crustal elements (Al, Si, Ti, Fe) and potassium in the fine mode. During these episodes, median particle absorption coefficients increased by a factor of 2, whereas median SSA values decreased by 7 %, in comparison to wet season conditions. |
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Long term measurements of aerosol optical properties at a primary forest site in AmazoniaA long term experiment was conducted in a primary forest area in Amazonia, with continuous in-situ measurements of aerosol optical properties between February 2008 and April 2011, comprising, to our knowledge, the longest database ever in the Amazon Basin. Two major classes of aerosol particles, with significantly different optical properties were identified: coarse mode predominant biogenic aerosols in the wet season (January-June), naturally released by the forest metabolism, and fine mode dominated biomass burning aerosols in the dry season (July-December), transported from regional fires. Dry particle median scattering coefficients at the wavelength of 550 nm increased from 6.3 Mm(-1) to 22 Mm(-1), whereas absorption at 637 nm increased from 0.5 Mm(-1) to 2.8 Mm(-1) from wet to dry season. Most of the scattering in the dry season was attributed to the predominance of fine mode (PM2) particles (40-80% of PM10 mass), while the enhanced absorption coefficients are attributed to the presence of light absorbing aerosols from biomass burning. As both scattering and absorption increased in the dry season, the single scattering albedo (SSA) did not show a significant seasonal variability, in average 0.86 +/- 0.08 at 637 nm for dry aerosols. Measured particle optical properties were used to estimate the aerosol forcing efficiency at the top of the atmosphere. Results indicate that in this primary forest site the radiative balance was dominated by the cloud cover, particularly in the wet season. Due to the high cloud fractions, the aerosol forcing efficiency absolute values were below -3.5 Wm(-2) in 70% of the wet season days and in 46% of the dry season days. Besides the seasonal variation, the influence of out-of-Basin aerosol sources was observed occasionally. Periods of influence of the Manaus urban plume were detected, characterized by a consistent increase on particle scattering (factor 2.5) and absorption coefficients (factor 5). Episodes of biomass burning and mineral dust particles advected from Africa were observed between January and April, characterized by enhanced concentrations of crustal elements (Al, Si, Ti, Fe) and potassium in the fine mode. During these episodes, median particle absorption coefficients increased by a factor of 2, whereas median SSA values decreased by 7 %, in comparison to wet season conditions.Universidade Federal de São Paulo, Inst Environm Chem & Pharmaceut Sci, Dept Earth & Exact Sci, São Paulo, BrazilUniv São Paulo, Inst Phys, Dept Appl Phys, São Paulo, BrazilLeibniz Inst Tropospher Res, Leipzig, GermanyNatl Inst Amazonian Res INPA, Manaus, Amazonas, BrazilLund Univ, Inst Phys, Div Nucl Phys, Lund, SwedenHarvard Univ, Dept Earth & Planetary Sci, Div Engn & Appl Sci, Cambridge, MA 02138 USAUniv Helsinki, Div Atmospher Sci, Dept Phys Sci, Helsinki, FinlandUniversidade Federal de São Paulo, Inst Environm Chem & Pharmaceut Sci, Dept Earth & Exact Sci, São Paulo, BrazilWeb of ScienceFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)European Integrated FP6 project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) under the scope of LBA experimentFAPESP: AEROCLIMA 08/58100-2European Integrated FP6 project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) under the scope of LBA experiment: 34684Copernicus Gesellschaft MbhUniversidade Federal de São Paulo (UNIFESP)Universidade de São Paulo (USP)Leibniz Inst Tropospher ResNatl Inst Amazonian Res INPALund UnivHarvard UnivUniv HelsinkiRizzo, Luciana Varanda [UNIFESP]Artaxo, PauloMueller, ThomasWiedensohler, AlfredPaixao, MelinaCirino, Glauber GuimarãesArana, AndreaSwietlicki, ErikRoldin, PontusFors, Erik O.Wiedemann, Kenia TeodoroLeal, L. S. M.Kulmala, Markku2016-01-24T14:30:58Z2016-01-24T14:30:58Z2013-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersion2391-2413application/pdfhttp://dx.doi.org/10.5194/acp-13-2391-2013Atmospheric Chemistry and Physics. Gottingen: Copernicus Gesellschaft Mbh, v. 13, n. 5, p. 2391-2413, 2013.10.5194/acp-13-2391-2013WOS000316960500006.pdf1680-7316http://repositorio.unifesp.br/handle/11600/35755WOS:000316960500006engAtmospheric Chemistry and Physicsinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UNIFESPinstname:Universidade Federal de São Paulo (UNIFESP)instacron:UNIFESP2024-08-01T04:42:52Zoai:repositorio.unifesp.br/:11600/35755Repositório InstitucionalPUBhttp://www.repositorio.unifesp.br/oai/requestbiblioteca.csp@unifesp.bropendoar:34652024-08-01T04:42:52Repositório Institucional da UNIFESP - Universidade Federal de São Paulo (UNIFESP)false |
dc.title.none.fl_str_mv |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
title |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
spellingShingle |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia Rizzo, Luciana Varanda [UNIFESP] |
title_short |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
title_full |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
title_fullStr |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
title_full_unstemmed |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
title_sort |
Long term measurements of aerosol optical properties at a primary forest site in Amazonia |
author |
Rizzo, Luciana Varanda [UNIFESP] |
author_facet |
Rizzo, Luciana Varanda [UNIFESP] Artaxo, Paulo Mueller, Thomas Wiedensohler, Alfred Paixao, Melina Cirino, Glauber Guimarães Arana, Andrea Swietlicki, Erik Roldin, Pontus Fors, Erik O. Wiedemann, Kenia Teodoro Leal, L. S. M. Kulmala, Markku |
author_role |
author |
author2 |
Artaxo, Paulo Mueller, Thomas Wiedensohler, Alfred Paixao, Melina Cirino, Glauber Guimarães Arana, Andrea Swietlicki, Erik Roldin, Pontus Fors, Erik O. Wiedemann, Kenia Teodoro Leal, L. S. M. Kulmala, Markku |
author2_role |
author author author author author author author author author author author author |
dc.contributor.none.fl_str_mv |
Universidade Federal de São Paulo (UNIFESP) Universidade de São Paulo (USP) Leibniz Inst Tropospher Res Natl Inst Amazonian Res INPA Lund Univ Harvard Univ Univ Helsinki |
dc.contributor.author.fl_str_mv |
Rizzo, Luciana Varanda [UNIFESP] Artaxo, Paulo Mueller, Thomas Wiedensohler, Alfred Paixao, Melina Cirino, Glauber Guimarães Arana, Andrea Swietlicki, Erik Roldin, Pontus Fors, Erik O. Wiedemann, Kenia Teodoro Leal, L. S. M. Kulmala, Markku |
description |
A long term experiment was conducted in a primary forest area in Amazonia, with continuous in-situ measurements of aerosol optical properties between February 2008 and April 2011, comprising, to our knowledge, the longest database ever in the Amazon Basin. Two major classes of aerosol particles, with significantly different optical properties were identified: coarse mode predominant biogenic aerosols in the wet season (January-June), naturally released by the forest metabolism, and fine mode dominated biomass burning aerosols in the dry season (July-December), transported from regional fires. Dry particle median scattering coefficients at the wavelength of 550 nm increased from 6.3 Mm(-1) to 22 Mm(-1), whereas absorption at 637 nm increased from 0.5 Mm(-1) to 2.8 Mm(-1) from wet to dry season. Most of the scattering in the dry season was attributed to the predominance of fine mode (PM2) particles (40-80% of PM10 mass), while the enhanced absorption coefficients are attributed to the presence of light absorbing aerosols from biomass burning. As both scattering and absorption increased in the dry season, the single scattering albedo (SSA) did not show a significant seasonal variability, in average 0.86 +/- 0.08 at 637 nm for dry aerosols. Measured particle optical properties were used to estimate the aerosol forcing efficiency at the top of the atmosphere. Results indicate that in this primary forest site the radiative balance was dominated by the cloud cover, particularly in the wet season. Due to the high cloud fractions, the aerosol forcing efficiency absolute values were below -3.5 Wm(-2) in 70% of the wet season days and in 46% of the dry season days. Besides the seasonal variation, the influence of out-of-Basin aerosol sources was observed occasionally. Periods of influence of the Manaus urban plume were detected, characterized by a consistent increase on particle scattering (factor 2.5) and absorption coefficients (factor 5). Episodes of biomass burning and mineral dust particles advected from Africa were observed between January and April, characterized by enhanced concentrations of crustal elements (Al, Si, Ti, Fe) and potassium in the fine mode. During these episodes, median particle absorption coefficients increased by a factor of 2, whereas median SSA values decreased by 7 %, in comparison to wet season conditions. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-01-01 2016-01-24T14:30:58Z 2016-01-24T14:30:58Z |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.5194/acp-13-2391-2013 Atmospheric Chemistry and Physics. Gottingen: Copernicus Gesellschaft Mbh, v. 13, n. 5, p. 2391-2413, 2013. 10.5194/acp-13-2391-2013 WOS000316960500006.pdf 1680-7316 http://repositorio.unifesp.br/handle/11600/35755 WOS:000316960500006 |
url |
http://dx.doi.org/10.5194/acp-13-2391-2013 http://repositorio.unifesp.br/handle/11600/35755 |
identifier_str_mv |
Atmospheric Chemistry and Physics. Gottingen: Copernicus Gesellschaft Mbh, v. 13, n. 5, p. 2391-2413, 2013. 10.5194/acp-13-2391-2013 WOS000316960500006.pdf 1680-7316 WOS:000316960500006 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Atmospheric Chemistry and Physics |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
2391-2413 application/pdf |
dc.publisher.none.fl_str_mv |
Copernicus Gesellschaft Mbh |
publisher.none.fl_str_mv |
Copernicus Gesellschaft Mbh |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UNIFESP instname:Universidade Federal de São Paulo (UNIFESP) instacron:UNIFESP |
instname_str |
Universidade Federal de São Paulo (UNIFESP) |
instacron_str |
UNIFESP |
institution |
UNIFESP |
reponame_str |
Repositório Institucional da UNIFESP |
collection |
Repositório Institucional da UNIFESP |
repository.name.fl_str_mv |
Repositório Institucional da UNIFESP - Universidade Federal de São Paulo (UNIFESP) |
repository.mail.fl_str_mv |
biblioteca.csp@unifesp.br |
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1814268402940772352 |