scholarly journals Profiling of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon: normalized excess mixing ratios and related emission factors in biomass burning plumes

2020 ◽  
Vol 20 (20) ◽  
pp. 12363-12389
Author(s):  
Flora Kluge ◽  
Tilman Hüneke ◽  
Matthias Knecht ◽  
Michael Lichtenstern ◽  
Meike Rotermund ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Amazon Basin ◽  
Emission Factors ◽  
Oxidation Products ◽  
Back Trajectory ◽  
Near Surface ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Research Aircraft ◽  
The Mean

Abstract. We report on airborne measurements of tropospheric mixing ratios and vertical profiles of formaldehyde (CH2O), glyoxal (C2H2O2), methylglyoxal and higher carbonyls (C3H4O2*) (see below), and carbon monoxide (CO) over the Amazon Basin during the ACRIDICON-CHUVA campaign from the German High Altitude and Long-range research aircraft (HALO) in autumn 2014. The joint observation of in situ CO and remotely measured CH2O, C2H2O2, and C3H4O2*, together with visible imagery and air mass back-trajectory modelling using NOAA HYSPLIT (National Oceanic Atmospheric Administration, HYbrid Single-Particle Lagrangian Integrated Trajectory), allows us to discriminate between the probing of background tropical air, in which the concentration of the measured species results from the oxidation of biogenically emitted volatile organic compounds (VOCs, mostly isoprene), and measurements of moderately to strongly polluted air masses affected by biomass burning emissions or the city plume of Manaus. For 12 near-surface measurements of fresh biomass burning plumes, normalized excess mixing ratios of C2H2O2 and C3H4O2* with respect to CH2O are inferred and compared to recent studies. The mean glyoxal-to-formaldehyde ratio RGF=0.07 (range 0.02–0.11) is in good agreement with recent reports which suggest RGF to be significantly lower than previously assumed in global chemical transport models (CTMs). The mean methylglyoxal-to-formaldehyde ratio RMF=0.98 (range 0.09–1.50) varies significantly during the different observational settings but overall appears to be much larger (up to a factor of 5) than previous reports suggest even when applying a correction factor of 2.0±0.5 to account for the additional dicarbonyls included in the C3H4O2* measurements. Using recently reported emission factors of CH2O for tropical forests, our observations suggest emission factors of EFG=0.25 (range 0.11 to 0.52) g kg−1 for C2H2O2 and EFM = 4.7 (range 0.5 to 8.64) g kg−1 for C3H4O2*. While EFG agrees well with recent reports, EFM is (like RMF) slightly larger than reported in other studies, presumably due to the different plume ages or fuels studied. Our observations of these critical carbonyls and intermediate oxidation products may support future photochemical modelling of air pollution over tropical vegetation, as well as validate past and present space-borne observations of the respective species.

scholarly journals Profiling of formaldehyde, glyoxal, methylglyoxal, and CO over the Amazon: Normalised excess mixing ratios and related emission factors in biomass burning plumes

2020 ◽  
Author(s):  
Flora Kluge ◽  
Tilman Hüneke ◽  
Matthias Knecht ◽  
Michael Lichtenstern ◽  
Meike Rotermund ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Amazon Basin ◽  
Emission Factors ◽  
Oxidation Products ◽  
Back Trajectory ◽  
Near Surface ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Research Aircraft ◽  
The Mean

Abstract. We report on airborne measurements of tropospheric mixing ratios and vertical profiles of CH2O, C2H2O2, C3H4O2*, and CO over the Amazon Basin during the ACRIDICON-CHUVA campaign from the German High Altitude and Long-range research aircraft (HALO) in fall 2014. The joint observation of in situ CO and remotely measured CH2O, C2H2O2, C3H4O2*, together with visible imagery and air mass back trajectory modelling using NOAA HYSPLIT (National Oceanic Atmospheric Administration, HYbrid Single-Particle Lagrangian Integrated Trajectory) allow us to discriminate between the probing of background tropical air, in which the concentration of the measured species results from the oxidation of biogenically emitted VOCs (mostly isoprene), and measurements of moderately to strongly polluted air masses affected by biomass burning emissions or the city plume of Manaus. For twelve near surface measurements of fresh biomass burning plumes, normalized excess mixing ratios of C2H2O2 and C3H4O2* with respect to CH2O are inferred and compared to recent studies. The mean RGF = 0.07 (range 0.02–0.11) is in good agreement with recent reports which suggest RGF to be significantly lower than previously assumed in global CTM models. The mean RMF = 0.98 (range 0.09–1.50) varies significantly during the different observational settings, but overall appears to be much larger (up to a factor of 5) than previous reports suggest when applaying a correction factor of 2.0 ± 0.5 to account for the additional dicarbonyls included in the C3H4O2* measurements. Using recently reported emission factors of CH2O for tropical forests, our observations suggest emission factors of EFG = 0.25 (range 0.11 to 0.52) g per kg for C2H2O2, and EFM = 4.7 (range 0.5 to 8.64) g per kg for C3H4O2*. While EFG agrees well with recent reports, EFM is (like RMF) slightly larger than reported in other studies, presumably due to the different plume ages or fuels studied. Our observations of these critical carbonyls and intermediate oxidation products may support future photochemical modelling of air pollution over tropical vegetation, as well as validate past and present space-borne observations of the respective species.

scholarly journals An aircraft gas chromatograph–mass spectrometer System for Organic Fast Identification Analysis (SOFIA): design, performance and a case study of Asian monsoon pollution outflow

2017 ◽  
Vol 10 (12) ◽  
pp. 5089-5105 ◽  
Author(s):  
Efstratios Bourtsoukidis ◽  
Frank Helleis ◽  
Laura Tomsche ◽  
Horst Fischer ◽  
Rolf Hofmann ◽  
...  
Keyword(s):  
Time Resolution ◽  
Asian Monsoon ◽  
Electrical Safety ◽  
Back Trajectory ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Fast Identification ◽  
Chemistry Research ◽  
Identification Analysis

Abstract. Volatile organic compounds (VOCs) are important for global air quality and oxidation processes in the troposphere. In addition to ground-based measurements, the chemical evolution of such species during transport can be studied by performing in situ airborne measurements. Generally, aircraft instrumentation needs to be sensitive, robust and sample at higher frequency than ground-based systems while their construction must comply with rigorous mechanical and electrical safety standards. Here, we present a new System for Organic Fast Identification Analysis (SOFIA), which is a custom-built fast gas chromatography–mass spectrometry (GC-MS) system with a time resolution of 2–3 min and the ability to quantify atmospheric mixing ratios of halocarbons (e.g. chloromethanes), hydrocarbons (e.g isoprene), oxygenated VOCs (acetone, propanal, butanone) and aromatics (e.g. benzene, toluene) from sub-ppt to ppb levels. The relatively high time resolution is the result of a novel cryogenic pre-concentration unit which rapidly cools (∼ 6 °C s−1) the sample enrichment traps to −140 °C, and a new chromatographic oven designed for rapid cooling rates (∼ 30 °C s−1) and subsequent thermal stabilization. SOFIA was installed in the High Altitude and Long Range Research Aircraft (HALO) for the Oxidation Mechanism Observations (OMO) campaign in August 2015, aimed at investigating the Asian monsoon pollution outflow in the tropical upper troposphere. In addition to a comprehensive instrument characterization we present an example monsoon plume crossing flight as a case study to demonstrate the instrument capability. Hydrocarbon, halocarbon and oxygenated VOC data from SOFIA are compared with mixing ratios of carbon monoxide (CO) and methane (CH4), used to define the pollution plume. By using excess (ExMR) and normalized excess mixing ratios (NEMRs) the pollution could be attributed to two air masses of distinctly different origin, identified by back-trajectory analysis. This work endorses the use of SOFIA for aircraft operation and demonstrates the value of relatively high-frequency, multicomponent measurements in atmospheric chemistry research.

scholarly journals Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

2012 ◽  
Vol 12 (13) ◽  
pp. 6041-6065 ◽  
Author(s):  
M. O. Andreae ◽  
P. Artaxo ◽  
V. Beck ◽  
M. Bela ◽  
S. Freitas ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Large Scale ◽  
Amazon Basin ◽  
Photochemical Degradation ◽  
Wet Season ◽  
Biomass Smoke ◽  
Airborne Measurements ◽  
Basin Scale

Abstract. We present the results of airborne measurements of carbon monoxide (CO) and aerosol particle number concentration (CN) made during the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA) program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA) program. The experiment consisted of two aircraft campaigns during November–December 2008 (BARCA-A) and May–June 2009 (BARCA-B), which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin. Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008) originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009) low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm−3; the highest values were in the southern part of the Basin at altitudes of 1–3 km. The ΔCN/ΔCO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires. During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300–500 cm−3) prevailed basinwide, and CO mixing ratios were enhanced by only ~10 ppb above the mixing line between Northern and Southern Hemisphere air. There was no detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

scholarly journals Dynamic biomass burning emission factors and their impact on atmospheric CO mixing ratios

2013 ◽  
Vol 118 (12) ◽  
pp. 6797-6815 ◽  
Author(s):  
T. T. van Leeuwen ◽  
W. Peters ◽  
M. C. Krol ◽  
G. R. van der Werf
Keyword(s):  
Biomass Burning ◽  
Emission Factors ◽  
Mixing Ratios

scholarly journals Oxygenated compounds in aged biomass burning plumes over the Eastern Mediterranean: evidence for strong secondary production of methanol and acetone

2005 ◽  
Vol 5 (1) ◽  
pp. 39-46 ◽  
Author(s):  
R. Holzinger ◽  
J. Williams ◽  
G. Salisbury ◽  
T. Klüpfel ◽  
M. de Reus ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Secondary Production ◽  
Eastern Mediterranean ◽  
Proton Transfer Reaction ◽  
Tunable Diode Laser ◽  
Airborne Measurements ◽  
Mixing Ratios ◽  
Oxygenated Compounds ◽  
Laser Absorption ◽  
Secondary Formation

Abstract. Airborne measurements of acetone, methanol, PAN, acetonitrile (by Proton Transfer Reaction Mass Spectrometry), and CO (by Tunable Diode Laser Absorption Spectroscopy) have been performed during the Mediterranean Intensive Oxidants Study (MINOS August 2001). We have identified ten biomass burning plumes from strongly elevated acetonitrile mixing ratios. The characteristic biomass burning signatures obtained from these plumes reveal secondary production of acetone and methanol, while CO photochemically declines in the plumes. Mean excess mixing ratios - normalized to CO - of 1.8%, 0.20%, 3.8%, and 0.65% for acetone, acetonitrile, methanol, and PAN, respectively, were found. By scaling to an assumed global annual source of 663-807Tg CO, biomass burning emissions of 25-31 and 29-35 Tg/yr for acetone and methanol are estimated, respectively. Our measurements suggest that the present biomass burning contributions of acetone and methanol are significantly underestimated due to the neglect of secondary formation within the plume. Median acetonitrile mixing ratios throughout the troposphere were around 150pmol/mol, in accord with current biomass burning inventories and an atmospheric lifetime of ~6 months.

scholarly journals Real-time measurements of ammonia, acidic trace gases and water-soluble inorganic aerosol species at a rural site in the Amazon Basin

2004 ◽  
Vol 4 (4) ◽  
pp. 967-987 ◽  
Author(s):  
I. Trebs ◽  
F. X. Meixner ◽  
J. Slanina ◽  
R. Otjes ◽  
P. Jongejan ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Amazon Basin ◽  
Limit Of Detection ◽  
Trace Gases ◽  
Water Soluble ◽  
Rural Site ◽  
Wet Season ◽  
Inlet System ◽  
Mixing Ratios ◽  
Inorganic Aerosol

Abstract. We measured the mixing ratios of ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO2 and the corresponding water-soluble inorganic aerosol species, ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), chloride (Cl- and sulfate (SO42-), and their diel and seasonal variations at a pasture site in the Amazon Basin (Rondônia, Brazil). This study was conducted within the framework of LBA-SMOCC (Large Scale Biosphere Atmosphere Experiment in Amazonia - Smoke Aerosols, Clouds, Rainfall and Climate: Aerosols from Biomass Burning Perturb Global and Regional Climate). Sampling was performed from 12 September to 14 November 2002, extending from the dry season (extensive biomass burning activity), through the transition period to the wet season (background conditions). Measurements were made continuously using a wet-annular denuder (WAD) in combination with a Steam-Jet Aerosol Collector (SJAC) followed by suitable on-line analysis. A detailed description and verification of the inlet system for simultaneous sampling of soluble gases and aerosol compounds is presented. Overall measurement uncertainties of the ambient mixing ratios usually remained below 15%. The limit of detection (LOD) was determined for each single data point measured during the field experiment. Median LOD values (3σ-definition) were ≤0.015ppb for acidic trace gases and aerosol anions and ≤0.118ppb for NH3 and aerosol NH4+. Mixing ratios of acidic trace gases remained below 1ppb throughout the measurement period, while NH3 levels were an order of magnitude higher. Accordingly, mixing ratios of NH4+ exceeded those of other inorganic aerosol contributors by a factor of 4 to 10. During the wet season, mixing ratios decreased by nearly a factor of 3 for all compounds compared to those observed when intensive biomass burning took place. Additionally, N-containing gas and aerosol species featured pronounced diel variations. This is attributed to strong relative humidity and temperature variations between day and night as well as to changing photochemistry and stability conditions of the planetary boundary layer. HONO exhibited a characteristic diel cycle with high mixing ratios at nighttime and was not completely depleted by photolysis during daylight hours.

scholarly journals Peroxy radical observations over West Africa during the AMMA 2006 campaign: Photochemical activity in episodes of formation of convective systems on the basis of radical measurements

2009 ◽  
Vol 9 (1) ◽  
pp. 1585-1619 ◽  
Author(s):  
M. D. Andrés-Hernández ◽  
D. Kartal ◽  
L. Reichert ◽  
J. P. Burrows ◽  
J. Meyer Arnek ◽  
...  
Keyword(s):  
West Africa ◽  
Biomass Burning ◽  
Peroxy Radical ◽  
Photochemical Activity ◽  
Back Trajectory ◽  
Peroxy Radicals ◽  
Air Masses ◽  
Convective Systems ◽  
Mixing Ratios ◽  
Multidisciplinary Analysis

Abstract. Peroxy radical measurements made on board the DLR-Falcon research aircraft over West Africa within the African Monsoon Multidisciplinary Analysis (AMMA) campaign during the 2006 wet monsoon are presented in this study. The analysis of data focuses on the photochemical activity of air masses sampled during episodes of intense convection and biomass burning. Generally, the total sum of peroxy radical mixing ratios, measured in the outflow of convective clouds, are quite variable but occasionally are coupled with the NO variations indicating the coexistence, or simultaneously emission of NOx, with a potential radical precursor (i.e., formaldehyde, acetone or peroxides) which has likely been transported to higher atmospheric layers. Based on the measurements, significant O3 production rates up to 2 ppb/h in the MCS outflow are estimated by using a box model with simplified chemistry. Peroxy radicals having mixing ratios around 20–25 pptv and with peak values of up to 60–70 pptv are measured within biomass burning plumes, detected at the coast in Ghana. Calculations of back-trajectory densities confirm the origin of these air masses being a biomass burning region at southern latitudes and close to the Gulf of Guinea, according to satellite pictures. Measured peroxy radical concentrations agree reasonably with modelled estimations taking into account simple local chemistry. Moreover the vertical profiles taken at the aircraft base in Ouagadougou, Burkina Faso, indicate the common feature of having maximum concentrations between 2 and 4 km, in agreement with other literature values obtained under similar conditions.

scholarly journals Development of a cavity enhanced absorption spectrometer for airborne measurements of CH<sub>4</sub> and CO<sub>2</sub>

2013 ◽  
Vol 6 (1) ◽  
pp. 1-41 ◽  
Author(s):  
S. J. O'Shea ◽  
S. J.-B. Bauguitte ◽  
M. W. Gallagher ◽  
D. Lowry ◽  
C. J. Percival
Keyword(s):  
Biomass Burning ◽  
Dry Matter ◽  
First Year ◽  
Airborne Measurements ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Research Aircraft ◽  
Infrared Spectrometer ◽  
Long Term Performance ◽  
Term Performance

Abstract. High-resolution CH4 and CO2 measurements were made onboard the FAAM BAe 146 UK atmospheric research aircraft during a number of field campaigns. The system was based on an infrared spectrometer using the cavity enhanced absorption spectroscopy technique. Correction functions to convert the mole fractions retrieved from the spectroscopy to dry air mole fractions were derived using laboratory experiments and over a 3 month period showed good stability. Long-term performance of the system was monitored using WMO traceable calibration gases. During the first year of operation (29 flights) analysis of the system's in-flight calibrations suggest that its measurements are accurate to −0.07 ppbv (1 σ precision at 1 Hz = 2.48 ppbv) for CH4 and −0.06 ppmv (1 σ precision at 1 Hz = 0.66 ppmv) for CO2. The system was found to be very robust, no major motion or altitude dependency could be detected in the measurements. An inter-comparison between whole air samples that were analysed post-flight for CH4 and CO2 by cavity ring down spectroscopy showed a mean difference between the two techniques of −2.4 ppbv (1 σ = 2.3 ppbv) for CH4 and −0.22 ppmv (1 σ = 0.45 ppmv) for CO2. In September 2012, the system was used to sample biomass burning plumes in Brazil as part of the SAMBBA project (South American biomass burning analysis). From these and simultaneous CO measurements, emission factors for savannah fires were calculated. These were found to be 2.2 ± 0.2 g (kg dry matter)−1 for CH4 and 1710 ± 171 g (kg dry matter)−1 for CO2, which are in excellent agreement with previous estimates in the literature.

scholarly journals Development of a cavity-enhanced absorption spectrometer for airborne measurements of CH<sub>4</sub> and CO<sub>2</sub>

2013 ◽  
Vol 6 (5) ◽  
pp. 1095-1109 ◽  
Author(s):  
S. J. O'Shea ◽  
S. J.-B. Bauguitte ◽  
M. W. Gallagher ◽  
D. Lowry ◽  
C. J. Percival
Keyword(s):  
Biomass Burning ◽  
Dry Matter ◽  
First Year ◽  
Atmospheric Measurements ◽  
Airborne Measurements ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Research Aircraft ◽  
Infrared Spectrometer ◽  
Term Performance

Abstract. High-resolution CH4 and CO2 measurements were made on board the FAAM BAe-146 UK (Facility for Airborne Atmospheric Measurements, British Aerospace-146) atmospheric research aircraft during a number of field campaigns. The system was based on an infrared spectrometer using the cavity-enhanced absorption spectroscopy technique. Correction functions to convert the mole fractions retrieved from the spectroscopy to dry-air mole fractions were derived using laboratory experiments and over a 3 month period showed good stability. Long-term performance of the system was monitored using WMO (World Meteorological Office) traceable calibration gases. During the first year of operation (29 flights) analysis of the system's in-flight calibrations suggest that its measurements are accurate to 1.28 ppb (1σ repeatability at 1 Hz = 2.48 ppb) for CH4 and 0.17 ppm (1σ repeatability at 1 Hz = 0.66 ppm) for CO2. The system was found to be robust, no major motion or altitude dependency could be detected in the measurements. An inter-comparison between whole-air samples that were analysed post-flight for CH4 and CO2 by cavity ring-down spectroscopy showed a mean difference between the two techniques of −2.4 ppb (1σ = 2.3 ppb) for CH4 and −0.22 ppm (1σ = 0.45 ppm) for CO2. In September 2012, the system was used to sample biomass-burning plumes in Brazil as part of the SAMBBA project (South AMerican Biomass Burning Analysis). From these and simultaneous CO measurements, emission factors for savannah fires were calculated. These were found to be 2.2 ± 0.2 g (kg dry matter)−1 for CH4 and 1710 ± 171 g (kg dry matter)−1 for CO2, which are in excellent agreement with previous estimates in the literature.

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