Long term measurements of aerosol optical properties at a primary forest site in Amazonia

Detalhes bibliográficos
Autor(a) principal: Rizzo, Luciana Varanda [UNIFESP]
Data de Publicação: 2013
Outros Autores: 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
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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spelling 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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