Advanced search
1 file | 2.20 MB

Evaluation of the carbon content of aerosols from the burning of biomass in the Brazilian Amazon using thermal, optical and thermal-optical analysis methods

(2011) ATMOSPHERIC CHEMISTRY AND PHYSICS. 11(9). p.4425-4444
Author
Organization
Abstract
Aerosol samples were collected at a pasture site in the Amazon Basin as part of the project LBA-SMOCC-2002 (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate). Sampling was conducted during the late dry season, when the aerosol composition was dominated by biomass burning emissions, especially in the submicron fraction. A 13-stage Dekati low-pressure impactor (DLPI) was used to collect particles with nominal aerodynamic diameters (D(p)) ranging from 0.03 to 0.10 mu m. Gravimetric analyses of the DLPI substrates and filters were performed to obtain aerosol mass concentrations. The concentrations of total, apparent elemental, and organic carbon (TC, EC(a), and OC) were determined using thermal and thermal-optical analysis (TOA) methods. A light transmission method (LTM) was used to determine the concentration of equivalent black carbon (BC(e)) or the absorbing fraction at 880 nm for the size-resolved samples. During the dry period, due to the pervasive presence of fires in the region upwind of the sampling site, concentrations of fine aerosols (D(p) < 2.5 mu m: average 59.8 mu g m(-3)) were higher than coarse aerosols (D(p) > 2.5 mu m: 4.1 mu g m(-3)). Carbonaceous matter, estimated as the sum of the particulate organic matter (i.e., OC x 1.8) plus BC(e), comprised more than 90% to the total aerosol mass. Concentrations of EC(a) (estimated by thermal analysis with a correction for charring) and BC(e) (estimated by LTM) averaged 5.2 +/- 1.3 and 3.1 +/- 0.8 mu g m(-3), respectively. The determination of EC was improved by extracting water-soluble organic material from the samples, which reduced the average light absorption Angstrom exponent of particles in the size range of 0.1 to 1.0 mu m from >2.0 to approximately 1.2. The size-resolved BC(e) measured by the LTM showed a clear maximum between 0.4 and 0.6 mu m in diameter. The concentrations of OC and BC(e) varied diurnally during the dry period, and this variation is related to diurnal changes in boundary layer thickness and in fire frequency.
Keywords
BLACK CARBON, ELEMENTAL CARBON, LONG-RANGE TRANSPORT, SOLUBLE ORGANIC-COMPOUNDS, ATMOSPHERIC AEROSOLS, PHYSICAL-PROPERTIES, SIZE DISTRIBUTION, LIGHT-ABSORPTION, AIRBORNE MEASUREMENTS, CHEMICAL-COMPOSITION

Downloads

  • soto acp-11-4425-2011.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 2.20 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Soto-Garcia, LL, MO Andreae, TW Andreae, P Artaxo, Willy Maenhaut, T Kirchstetter, T Novakov, JC Chow, and OL Mayol-Bracero. 2011. “Evaluation of the Carbon Content of Aerosols from the Burning of Biomass in the Brazilian Amazon Using Thermal, Optical and Thermal-optical Analysis Methods.” Atmospheric Chemistry and Physics 11 (9): 4425–4444.
APA
Soto-Garcia, L., Andreae, M., Andreae, T., Artaxo, P., Maenhaut, W., Kirchstetter, T., Novakov, T., et al. (2011). Evaluation of the carbon content of aerosols from the burning of biomass in the Brazilian Amazon using thermal, optical and thermal-optical analysis methods. ATMOSPHERIC CHEMISTRY AND PHYSICS, 11(9), 4425–4444.
Vancouver
1.
Soto-Garcia L, Andreae M, Andreae T, Artaxo P, Maenhaut W, Kirchstetter T, et al. Evaluation of the carbon content of aerosols from the burning of biomass in the Brazilian Amazon using thermal, optical and thermal-optical analysis methods. ATMOSPHERIC CHEMISTRY AND PHYSICS. 2011;11(9):4425–44.
MLA
Soto-Garcia, LL, MO Andreae, TW Andreae, et al. “Evaluation of the Carbon Content of Aerosols from the Burning of Biomass in the Brazilian Amazon Using Thermal, Optical and Thermal-optical Analysis Methods.” ATMOSPHERIC CHEMISTRY AND PHYSICS 11.9 (2011): 4425–4444. Print.
@article{2073604,
  abstract     = {Aerosol samples were collected at a pasture site in the Amazon Basin as part of the project LBA-SMOCC-2002 (Large-Scale Biosphere-Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate). Sampling was conducted during the late dry season, when the aerosol composition was dominated by biomass burning emissions, especially in the submicron fraction. A 13-stage Dekati low-pressure impactor (DLPI) was used to collect particles with nominal aerodynamic diameters (D(p)) ranging from 0.03 to 0.10 mu m. Gravimetric analyses of the DLPI substrates and filters were performed to obtain aerosol mass concentrations. The concentrations of total, apparent elemental, and organic carbon (TC, EC(a), and OC) were determined using thermal and thermal-optical analysis (TOA) methods. A light transmission method (LTM) was used to determine the concentration of equivalent black carbon (BC(e)) or the absorbing fraction at 880 nm for the size-resolved samples. 
During the dry period, due to the pervasive presence of fires in the region upwind of the sampling site, concentrations of fine aerosols (D(p) {\textlangle} 2.5 mu m: average 59.8 mu g m(-3)) were higher than coarse aerosols (D(p) {\textrangle} 2.5 mu m: 4.1 mu g m(-3)). Carbonaceous matter, estimated as the sum of the particulate organic matter (i.e., OC x 1.8) plus BC(e), comprised more than 90\% to the total aerosol mass. Concentrations of EC(a) (estimated by thermal analysis with a correction for charring) and BC(e) (estimated by LTM) averaged 5.2 +/- 1.3 and 3.1 +/- 0.8 mu g m(-3), respectively. The determination of EC was improved by extracting water-soluble organic material from the samples, which reduced the average light absorption Angstrom exponent of particles in the size range of 0.1 to 1.0 mu m from {\textrangle}2.0 to approximately 1.2. The size-resolved BC(e) measured by the LTM showed a clear maximum between 0.4 and 0.6 mu m in diameter. The concentrations of OC and BC(e) varied diurnally during the dry period, and this variation is related to diurnal changes in boundary layer thickness and in fire frequency.},
  author       = {Soto-Garcia, LL and Andreae, MO and Andreae, TW and Artaxo, P and Maenhaut, Willy and Kirchstetter, T and Novakov, T and Chow, JC and Mayol-Bracero, OL},
  issn         = {1680-7316},
  journal      = {ATMOSPHERIC CHEMISTRY AND PHYSICS},
  keyword      = {BLACK CARBON,ELEMENTAL CARBON,LONG-RANGE TRANSPORT,SOLUBLE ORGANIC-COMPOUNDS,ATMOSPHERIC AEROSOLS,PHYSICAL-PROPERTIES,SIZE DISTRIBUTION,LIGHT-ABSORPTION,AIRBORNE MEASUREMENTS,CHEMICAL-COMPOSITION},
  language     = {eng},
  number       = {9},
  pages        = {4425--4444},
  title        = {Evaluation of the carbon content of aerosols from the burning of biomass in the Brazilian Amazon using thermal, optical and thermal-optical analysis methods},
  url          = {http://dx.doi.org/10.5194/acp-11-4425-2011},
  volume       = {11},
  year         = {2011},
}

Altmetric
View in Altmetric
Web of Science
Times cited: