Use of levoglucosan, potassium, and water-soluble organic carbon to characterize the origins of biomass-burning aerosols

Autor(es)

Urban, Roberta Cerasi ^[1] ; Lima-Souza, Michele ^[2] ; Caetano-Silva, Leticia ^[2] ; Queiroz, Maria Eugenia C. ^[1] ; Nogueira, Raquel F. P. ^[2] ; Allen, Andrew G. ^[2] ; Cardoso, Arnaldo A. ^[2] ; Held, Gerhard ^[3] ; Campos, Maria Lucia A. M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Estadual Paulista, UNESP, Inst Quim, BR-14800900 Araraquara, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Inst Pesquisas Meteorol, BR-17048699 Bauru, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Atmospheric Environment; v. 61, p. 562-569, DEC 2012.
• Citações Web of Science: 43

Resumo

Three chemical species related to biomass burning, levoglucosan, potassium and water-soluble organic carbon (WSOC), were measured in aerosol samples collected in a rural area on the outskirts of the municipality of Ourinhos (Sao Paulo State, Brazil). This region is representative of the rural interior of the State, where the economy is based on agro-industrial production, and the most important crop is sugar cane. The manual harvesting process requires that the cane be first burned to remove excess foliage, leading to large emissions of particulate materials to the atmosphere. Most of the levoglucosan (68-89%) was present in small particles (<1.5 mu m), and its concentration in total aerosol ranged from 25 to 1186 ng m(-3). The highest values were found at night, when most of the biomass burning occurs. In contrast, WSOC showed no diurnal pattern, with an average concentration of 5.38 +/- 2.97 mu g m(-3) (n = 27). A significant linear correlation between levoglucosan and WSOC (r = 0.54; n = 26; p < 0.0001) confirmed that biomass burning was in fact an important source of WSOC in the study region. A moderate (but significant) linear correlation between levoglucosan and potassium concentrations (r = 0.62; n = 40; p < 0.0001) was indicative of the influence of other sources of potassium in the study region, such as soil resuspension and fertilizers. When only the fine particles (<1.5 pm; typical of biomass burning) were considered, the linear coefficient increased to 0.91 (n = 9). In this case, the average levoglucosan/K+ ratio was 0.24, which may be typical of biomass burning in the study region. This ratio is about 5 times lower than that previously found for Amazon aerosol collected during the day, when flaming combustion prevails. This suggests that the levoglucosan/K+ ratio may be especially helpful for characterization of the type of vegetation burned (such as crops or forest), when biomass-burning is the dominant source of potassium. The relatively high concentrations of WSOC (and inorganic ions) suggest an important influence on the formation of cloud condensation nuclei, which is likely to affect cloud formation and precipitation patterns. (C) 2012 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 10/50236-2 - A utilização de levoglucosan como marcador de queima de biomassa no material particulado de uma região canavieira do estado de São Paulo
• Beneficiário: Roberta Cerasi Urban
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 09/07415-6 - Proposta para pesquisador visitante
• Beneficiário: Arnaldo Alves Cardoso
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 08/58073-5 - Effects of emissions on current and future rainfall patterns in southeast Brazil
• Beneficiário: Arnaldo Alves Cardoso
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático