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M O Andreae - One of the best experts on this subject based on the ideXlab platform.

  • emission of trace gases and aerosols from Biomass Burning an updated assessment
    Atmospheric Chemistry and Physics, 2019
    Co-Authors: M O Andreae
    Abstract:

    Abstract. Since the publication of the compilation of Biomass Burning emission factors by Andreae and Merlet (2001), a large number of studies have greatly expanded the amount of available data on emissions from various types of Biomass Burning. Using essentially the same methodology as Andreae and Merlet (2001), this paper presents an updated compilation of emission factors. The data from over 370 published studies were critically evaluated and integrated into a consistent format. Several new categories of Biomass Burning were added, and the number of species for which emission data are presented was increased from 93 to 121. Where field data are still insufficient, estimates based on appropriate extrapolation techniques are proposed. For key species, the updated emission factors are compared with previously published values. Based on these emission factors and published global activity estimates, I have derived estimates of pyrogenic emissions for important species released by the various types of Biomass Burning.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    'Copernicus GmbH', 2016
    Co-Authors: Brito J, L V Rizzo, W T Morgan, M O Andreae, Coe H, Johnson B, Haywood J, Longo K, Freitas S, Artaxo P
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ∼ 1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 µg m−3 and peak concentrations close to 100 µg m−3 . Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 µg m−3 . The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 µg m−3 , respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 µg m−3 , with an average concentration of 1.3 µg m−3 . During BB peaks, organics accounted for over 90 % of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ∼= 0.25 to O : C ∼= 0.6), no remarkable change is observed in the H : C ratio (∼ 1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C/O : C slope of −0.5, possibly due to the development of a combination of BB (H : C/O : C slope = 0) and biogenic (H : C/O : C slope = −1) organic aerosol (OA). An analysis of the 1OA/1CO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume Published by Copernicus Publications on behalf of the European Geosciences Union. 12070 J. Brito et al.: Ground-based aerosol characterization during SAMBBA processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.This work was supported by the Foundation for Research Support of the State of São Paulo (FAPESP, projects 2012/14437-9 and 2013/05014-0), CNPq project 475735- 2012-9, INCT Amazonia, and Natural Environment Research Council (NERC) project NE/J010073/1. We thank A. Ribeiro, A. L. Loureiro, F. Morais, F. Jorge, and S. Morais for technical and logistics support. We thank the National Institute of Meteorology for providing valuable meteorological data. We gratefully acknowledge S. Hacon, J. Silva, and W. Bastos for support in the successful operation of the sampling site

  • ground based aerosol characterization during the south american Biomass Burning analysis sambba field experiment
    Atmospheric Chemistry and Physics, 2014
    Co-Authors: Joel Brito, S R Freitas, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, K M Longo, M O Andreae
    Abstract:

    Abstract. This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondonia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    Copernicus Publications, 2014
    Co-Authors: Joel Brito, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, M O Andreae, K. Longo, S. Freitas, P. Artaxo
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem

  • the influence of tropical Biomass Burning on climate and the atmospheric environment
    1993
    Co-Authors: M O Andreae
    Abstract:

    This chapter presents a review of the historical, economic, and environmental aspects of Biomass Burning. The use and extent of Biomass Burning in agriculture and various economic activities and its geographical distribution are outlined. The resulting emissions of gases and aerosols to the atmosphere are estimated based on field and laboratory measurements. Chemical processes in the emission plumes and their atmospheric transport on the regional to global scale are evaluated. The impact of the emissions from Biomass Burning on climate and the environment is shown to be, in many respects, of a magnitude comparable to the effects of the emissions from fossil fuel combustion.

Jim Haywood - One of the best experts on this subject based on the ideXlab platform.

  • ground based aerosol characterization during the south american Biomass Burning analysis sambba field experiment
    Atmospheric Chemistry and Physics, 2014
    Co-Authors: Joel Brito, S R Freitas, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, K M Longo, M O Andreae
    Abstract:

    Abstract. This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondonia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    Copernicus Publications, 2014
    Co-Authors: Joel Brito, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, M O Andreae, K. Longo, S. Freitas, P. Artaxo
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem

  • aging of Biomass Burning aerosols over west africa aircraft measurements of chemical composition microphysical properties and emission ratios
    Journal of Geophysical Research, 2008
    Co-Authors: Gerard Capes, P I Williams, Ben Johnson, Jim Haywood, Gordon Mcfiggans, Hugh Coe
    Abstract:

    [1] This paper investigates the physical and chemical characteristics of Biomass Burning aerosol over West Africa using data from the UK Facility for Airborne Atmospheric Measurements aircraft. Measurements of Biomass Burning aerosol were made during the Dust and Biomass-Burning Experiment (DABEX) and Dust Outflow and Deposition to the Ocean (DODO) field experiments in January and February 2006. Layers of aged Biomass Burning aerosols were observed throughout the region, and fresh Biomass Burning aerosols were encountered during the penetration of smoke plumes at low altitudes. Vertical profiles of aerosol properties across the region are shown. Measurements from an Aerodyne Quadrupole Aerosol Mass Spectrometer (Q-AMS) show changes in chemical composition between fresh and aged Biomass Burning aerosols, over a region spanning thousands of kilometers. These data represent the first time that continental-scale variability in Biomass Burning aerosol composition has been observed. However, an almost linear relationship between organic aerosol mass concentration and carbon monoxide concentration was observed across the region. A net carbon loss occurs over the aerosol lifetime in the region owing to a combination of chemical processing and repartitioning of organic mass to the gas phase. Evolution of the number size distribution was observed, with coagulation concluded to be the dominant process involved, a finding supported by coagulation box modeling. Regional-scale emission ratios for organic (0.041) and black carbon (0.0072) with respect to CO have been estimated over West Africa, one of the largest sources of Biomass Burning globally. Biomass Burning emissions from the West African Sahel are poorly represented in the literature, and these results represent important continental-scale emissions. They are in good agreement with literature values from other regions.

Hugh Coe - One of the best experts on this subject based on the ideXlab platform.

  • ground based aerosol characterization during the south american Biomass Burning analysis sambba field experiment
    Atmospheric Chemistry and Physics, 2014
    Co-Authors: Joel Brito, S R Freitas, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, K M Longo, M O Andreae
    Abstract:

    Abstract. This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondonia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    Copernicus Publications, 2014
    Co-Authors: Joel Brito, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, M O Andreae, K. Longo, S. Freitas, P. Artaxo
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem

  • aging of Biomass Burning aerosols over west africa aircraft measurements of chemical composition microphysical properties and emission ratios
    Journal of Geophysical Research, 2008
    Co-Authors: Gerard Capes, P I Williams, Ben Johnson, Jim Haywood, Gordon Mcfiggans, Hugh Coe
    Abstract:

    [1] This paper investigates the physical and chemical characteristics of Biomass Burning aerosol over West Africa using data from the UK Facility for Airborne Atmospheric Measurements aircraft. Measurements of Biomass Burning aerosol were made during the Dust and Biomass-Burning Experiment (DABEX) and Dust Outflow and Deposition to the Ocean (DODO) field experiments in January and February 2006. Layers of aged Biomass Burning aerosols were observed throughout the region, and fresh Biomass Burning aerosols were encountered during the penetration of smoke plumes at low altitudes. Vertical profiles of aerosol properties across the region are shown. Measurements from an Aerodyne Quadrupole Aerosol Mass Spectrometer (Q-AMS) show changes in chemical composition between fresh and aged Biomass Burning aerosols, over a region spanning thousands of kilometers. These data represent the first time that continental-scale variability in Biomass Burning aerosol composition has been observed. However, an almost linear relationship between organic aerosol mass concentration and carbon monoxide concentration was observed across the region. A net carbon loss occurs over the aerosol lifetime in the region owing to a combination of chemical processing and repartitioning of organic mass to the gas phase. Evolution of the number size distribution was observed, with coagulation concluded to be the dominant process involved, a finding supported by coagulation box modeling. Regional-scale emission ratios for organic (0.041) and black carbon (0.0072) with respect to CO have been estimated over West Africa, one of the largest sources of Biomass Burning globally. Biomass Burning emissions from the West African Sahel are poorly represented in the literature, and these results represent important continental-scale emissions. They are in good agreement with literature values from other regions.

L V Rizzo - One of the best experts on this subject based on the ideXlab platform.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    'Copernicus GmbH', 2016
    Co-Authors: Brito J, L V Rizzo, W T Morgan, M O Andreae, Coe H, Johnson B, Haywood J, Longo K, Freitas S, Artaxo P
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ∼ 1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 µg m−3 and peak concentrations close to 100 µg m−3 . Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 µg m−3 . The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 µg m−3 , respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 µg m−3 , with an average concentration of 1.3 µg m−3 . During BB peaks, organics accounted for over 90 % of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ∼= 0.25 to O : C ∼= 0.6), no remarkable change is observed in the H : C ratio (∼ 1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C/O : C slope of −0.5, possibly due to the development of a combination of BB (H : C/O : C slope = 0) and biogenic (H : C/O : C slope = −1) organic aerosol (OA). An analysis of the 1OA/1CO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume Published by Copernicus Publications on behalf of the European Geosciences Union. 12070 J. Brito et al.: Ground-based aerosol characterization during SAMBBA processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.This work was supported by the Foundation for Research Support of the State of São Paulo (FAPESP, projects 2012/14437-9 and 2013/05014-0), CNPq project 475735- 2012-9, INCT Amazonia, and Natural Environment Research Council (NERC) project NE/J010073/1. We thank A. Ribeiro, A. L. Loureiro, F. Morais, F. Jorge, and S. Morais for technical and logistics support. We thank the National Institute of Meteorology for providing valuable meteorological data. We gratefully acknowledge S. Hacon, J. Silva, and W. Bastos for support in the successful operation of the sampling site

  • Biomass Burning related ozone damage on vegetation over the amazon forest a model sensitivity study
    Atmospheric Chemistry and Physics, 2015
    Co-Authors: F Pacifico, L V Rizzo, Gerd Folberth, Stephen Sitch, J M Haywood, F Malavelle, Paulo Artaxo
    Abstract:

    Abstract. The HadGEM2 earth system climate model was used to assess the impact of Biomass Burning on surface ozone concentrations over the Amazon forest and its impact on vegetation, under present-day climate conditions. Here we consider Biomass Burning emissions from wildfires, deforestation fires, agricultural forest Burning, and residential and commercial combustion. Simulated surface ozone concentration is evaluated against observations taken at two sites in the Brazilian Amazon forest for years 2010 to 2012. The model is able to reproduce the observed diurnal cycle of surface ozone mixing ratio at the two sites, but overestimates the magnitude of the monthly averaged hourly measurements by 5–15 ppb for each available month at one of the sites. We vary Biomass Burning emissions over South America by ±20, 40, 60, 80 and 100% to quantify the modelled impact of Biomass Burning on surface ozone concentrations and ozone damage on vegetation productivity over the Amazon forest. We used the ozone damage scheme in the "high" sensitivity mode to give an upper limit for this effect. Decreasing South American Biomass Burning emissions by 100% (i.e. to zero) reduces surface ozone concentrations (by about 15 ppb during the Biomass Burning season) and suggests a 15% increase in monthly mean net primary productivity averaged over the Amazon forest, with local increases up to 60%. The simulated impact of ozone damage from present-day Biomass Burning on vegetation productivity is about 230 TgC yr−1. Taking into account that uncertainty in these estimates is substantial, this ozone damage impact over the Amazon forest is of the same order of magnitude as the release of carbon dioxide due to fire in South America; in effect it potentially doubles the impact of Biomass Burning on the carbon cycle.

  • ground based aerosol characterization during the south american Biomass Burning analysis sambba field experiment
    Atmospheric Chemistry and Physics, 2014
    Co-Authors: Joel Brito, S R Freitas, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, K M Longo, M O Andreae
    Abstract:

    Abstract. This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondonia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    Copernicus Publications, 2014
    Co-Authors: Joel Brito, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, M O Andreae, K. Longo, S. Freitas, P. Artaxo
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem

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  • ground based aerosol characterization during the south american Biomass Burning analysis sambba field experiment
    Atmospheric Chemistry and Physics, 2014
    Co-Authors: Joel Brito, S R Freitas, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, K M Longo, M O Andreae
    Abstract:

    Abstract. This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondonia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem.

  • Ground-based aerosol characterization during the South American Biomass Burning Analysis (SAMBBA) field experiment
    Copernicus Publications, 2014
    Co-Authors: Joel Brito, L V Rizzo, W T Morgan, Hugh Coe, Ben Johnson, Jim Haywood, M O Andreae, K. Longo, S. Freitas, P. Artaxo
    Abstract:

    This paper investigates the physical and chemical characteristics of aerosols at ground level at a site heavily impacted by Biomass Burning. The site is located near Porto Velho, Rondônia, in the southwestern part of the Brazilian Amazon rainforest, and was selected for the deployment of a large suite of instruments, among them an Aerosol Chemical Speciation Monitor. Our measurements were made during the South American Biomass Burning Analysis (SAMBBA) field experiment, which consisted of a combination of aircraft and ground-based measurements over Brazil, aimed to investigate the impacts of Biomass Burning emissions on climate, air quality, and numerical weather prediction over South America. The campaign took place during the dry season and the transition to the wet season in September/October 2012. During most of the campaign, the site was impacted by regional Biomass Burning pollution (average CO mixing ratio of 0.6 ppm), occasionally superimposed by intense (up to 2 ppm of CO), freshly emitted Biomass Burning plumes. Aerosol number concentrations ranged from ~1000 cm−3 to peaks of up to 35 000 cm−3 (during Biomass Burning (BB) events, corresponding to an average submicron mass mean concentrations of 13.7 μg m−3 and peak concentrations close to 100 μg m−3. Organic aerosol strongly dominated the submicron non-refractory composition, with an average concentration of 11.4 μg m−3. The inorganic species, NH4, SO4, NO3, and Cl, were observed, on average, at concentrations of 0.44, 0.34, 0.19, and 0.01 μg m−3, respectively. Equivalent black carbon (BCe) ranged from 0.2 to 5.5 μg m−3, with an average concentration of 1.3 μg m−3. During BB peaks, organics accounted for over 90% of total mass (submicron non-refractory plus BCe), among the highest values described in the literature. We examined the ageing of Biomass Burning organic aerosol (BBOA) using the changes in the H : C and O : C ratios, and found that throughout most of the aerosol processing (O : C ≅ 0.25 to O : C ≅ 0.6), no remarkable change is observed in the H : C ratio (~1.35). Such a result contrasts strongly with previous observations of chemical ageing of both urban and Amazonian biogenic aerosols. At higher levels of processing (O : C > 0.6), the H : C ratio changes with a H : C / O : C slope of −0.5, possibly due to the development of a combination of BB (H : C / O : C slope = 0) and biogenic (H : C /O :C slope =−1) organic aerosol (OA). An analysis of the ΔOA /ΔCO mass ratios yields very little enhancement in the OA loading with atmospheric processing, consistent with previous observations. These results indicate that negligible secondary organic aerosol (SOA) formation occurs throughout the observed BB plume processing, or that SOA formation is almost entirely balanced by OA volatilization. Positive matrix factorization (PMF) of the organic aerosol spectra resulted in three factors: fresh BBOA, aged BBOA, and low-volatility oxygenated organic aerosol (LV-OOA). Analysis of the diurnal patterns and correlation with external markers indicates that during the first part of the campaign, OA concentrations are impacted by local fire plumes with some chemical processing occurring in the near-surface layer. During the second part of the campaign, long-range transport of BB plumes above the surface layer, as well as potential SOAs formed aloft, dominates OA concentrations at our ground-based sampling site. This manuscript describes the first ground-based deployment of the aerosol mass spectrometry at a site heavily impacted by Biomass Burning in the Amazon region, allowing a deeper understanding of aerosol life cycle in this important ecosystem

  • aging of Biomass Burning aerosols over west africa aircraft measurements of chemical composition microphysical properties and emission ratios
    Journal of Geophysical Research, 2008
    Co-Authors: Gerard Capes, P I Williams, Ben Johnson, Jim Haywood, Gordon Mcfiggans, Hugh Coe
    Abstract:

    [1] This paper investigates the physical and chemical characteristics of Biomass Burning aerosol over West Africa using data from the UK Facility for Airborne Atmospheric Measurements aircraft. Measurements of Biomass Burning aerosol were made during the Dust and Biomass-Burning Experiment (DABEX) and Dust Outflow and Deposition to the Ocean (DODO) field experiments in January and February 2006. Layers of aged Biomass Burning aerosols were observed throughout the region, and fresh Biomass Burning aerosols were encountered during the penetration of smoke plumes at low altitudes. Vertical profiles of aerosol properties across the region are shown. Measurements from an Aerodyne Quadrupole Aerosol Mass Spectrometer (Q-AMS) show changes in chemical composition between fresh and aged Biomass Burning aerosols, over a region spanning thousands of kilometers. These data represent the first time that continental-scale variability in Biomass Burning aerosol composition has been observed. However, an almost linear relationship between organic aerosol mass concentration and carbon monoxide concentration was observed across the region. A net carbon loss occurs over the aerosol lifetime in the region owing to a combination of chemical processing and repartitioning of organic mass to the gas phase. Evolution of the number size distribution was observed, with coagulation concluded to be the dominant process involved, a finding supported by coagulation box modeling. Regional-scale emission ratios for organic (0.041) and black carbon (0.0072) with respect to CO have been estimated over West Africa, one of the largest sources of Biomass Burning globally. Biomass Burning emissions from the West African Sahel are poorly represented in the literature, and these results represent important continental-scale emissions. They are in good agreement with literature values from other regions.