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Journal articles on the topic 'Forest-derived methane'
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1
Sinha, V., J. Williams, P. J. Crutzen, and J. Lelieveld. "Methane emissions from boreal and tropical forest ecosystems derived from in-situ measurements." Atmospheric Chemistry and Physics Discussions 7, no. 5 (September 28, 2007): 14011–39. http://dx.doi.org/10.5194/acpd-7-14011-2007.
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Abstract. Methane is a climatologically important greenhouse gas, which plays a key role in regulating water vapour in the stratosphere and hydroxyl radicals in the troposphere. Recent findings that vegetation emits methane have stimulated efforts to ascertain the impact of this source on the global budget. In this work, we present the results of high frequency (ca. 1 min−1) methane measurements conducted in the boreal forests of Finland and the tropical forests of Suriname, in April–May, 2005 and October 2005 respectively. The measurements were performed using a gas chromatograph – flame ionization detector (GC-FID). The average of the median mixing ratios during a typical diel cycle were 1.83 μmol mol−1 and 1.74 μmol mol−1 for the boreal forest ecosystem and tropical forest ecosystem respectively, with remarkable similarity in the time series of both the boreal and tropical diel profiles. Night time methane emission flux of the boreal forest ecosystem, calculated from the increase of methane during the night and measured nocturnal boundary layer heights yields a flux of (3.62±0.87)×1011 molecules cm−2 s−1(or 45.5±11 Tg CH4 yr−1 for global boreal forest area). This is a source contribution of circa 8% of the global methane budget. These results highlight the importance of the boreal and tropical forest ecosystems for the global budget of methane. The results are also discussed in the context of recent work reporting high methane mixing ratios over tropical forests using space borne near infra-red spectroscopy measurements.
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Lönnqvist, Tomas, Stefan Grönkvist, and Thomas Sandberg. "Forest-derived methane in the Swedish transport sector: A closing window?" Energy Policy 105 (June 2017): 440–50. http://dx.doi.org/10.1016/j.enpol.2017.03.003.
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Mohanty, Santosh R., Paul L. E. Bodelier, Virgilio Floris, and Ralf Conrad. "Differential Effects of Nitrogenous Fertilizers on Methane-Consuming Microbes in Rice Field and Forest Soils." Applied and Environmental Microbiology 72, no. 2 (February 2006): 1346–54. http://dx.doi.org/10.1128/aem.72.2.1346-1354.2006.
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ABSTRACT The impact of environmental perturbation (e.g., nitrogenous fertilizers) on the dynamics of methane fluxes from soils and wetland systems is poorly understood. Results of fertilizer studies are often contradictory, even within similar ecosystems. In the present study the hypothesis of whether these contradictory results may be explained by the composition of the methane-consuming microbial community and hence whether methanotrophic diversity affects methane fluxes was investigated. To this end, rice field and forest soils were incubated in microcosms and supplemented with different nitrogenous fertilizers and methane concentrations. By labeling the methane with 13C, diversity and function could be coupled by analyses of phospholipid-derived fatty acids (PLFA) extracted from the soils at different time points during incubation. In both rice field and forest soils, the activity as well as the growth rate of methane-consuming bacteria was affected differentially. For type I methanotrophs, fertilizer application stimulated the consumption of methane and the subsequent growth, while type II methanotrophs were generally inhibited. Terminal restriction fragment length polymorphism analyses of the pmoA gene supported the PLFA results. Multivariate analyses of stable-isotope-probing PLFA profiles indicated that in forest and rice field soils, Methylocystis (type II) species were affected by fertilization. The type I methanotrophs active in forest soils (Methylomicrobium/Methylosarcina related) differed from the active species in rice field soils (Methylobacter/Methylomonas related). Our results provide a case example showing that microbial community structure indeed matters, especially when assessing and predicting the impact of environmental change on biodiversity loss and ecosystem functioning.
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Lewis, A. C., M. J. Evans, J. R. Hopkins, S. Punjabi, K. A. Read, S. Andrews, S. J. Moller, et al. "The influence of boreal forest fires on the global distribution of non-methane hydrocarbons." Atmospheric Chemistry and Physics Discussions 12, no. 9 (September 10, 2012): 23433–69. http://dx.doi.org/10.5194/acpd-12-23433-2012.
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Abstract. Boreal forest fires are a significant source of chemicals to the atmosphere including numerous non-methane hydrocarbons (NMHCs). We report airborne measurements of NMHCs, acetone and methanol from > 500 whole air samples collected over Eastern Canada, including interception of several different boreal biomass burning plumes. From these and concurrent measurements of carbon monoxide (CO) we derive fire emission ratios for 29 different species relative to the emission of CO. These range from 8.9 ± 3.2 ppt ppb−1 CO for methanol to 0.007 ± 0.004 ppt ppb−1 CO for cyclopentane. The ratios are in good to excellent agreement with recent literature values. Using the GEOS-Chem global 3-D chemical transport model (CTM) we show the influence of biomass burning on the global distributions of benzene, toluene, ethene and propene (species considered generally as indicative tracers of anthropogenic activity). Using our derived emission ratios and the GEOS-Chem CTM, we show that biomass burning can be the largest fractional contributor to observed benzene, toluene, ethene and propene in many global locations. The widespread biomass burning contribution to atmospheric benzene, a heavily regulated air pollutant, suggests that pragmatic approaches are needed when setting air quality targets as tailpipe and solvent emissions continue to decline. We subsequently determine the extent to which the 28 Global WMO-GAW stations worldwide are influenced by biomass burning sourced benzene, toluene, ethene and propene when compared to their exposure to anthropogenic emissions.
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Henckel, Thilo, Udo Jäckel, Sylvia Schnell, and Ralf Conrad. "Molecular Analyses of Novel Methanotrophic Communities in Forest Soil That Oxidize Atmospheric Methane." Applied and Environmental Microbiology 66, no. 5 (May 1, 2000): 1801–8. http://dx.doi.org/10.1128/aem.66.5.1801-1808.2000.
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ABSTRACT Forest and other upland soils are important sinks for atmospheric CH4, consuming 20 to 60 Tg of CH4 per year. Consumption of atmospheric CH4 by soil is a microbiological process. However, little is known about the methanotrophic bacterial community in forest soils. We measured vertical profiles of atmospheric CH4 oxidation rates in a German forest soil and characterized the methanotrophic populations by PCR and denaturing gradient gel electrophoresis (DGGE) with primer sets targeting thepmoA gene, coding for the α subunit of the particulate methane monooxygenase, and the small-subunit rRNA gene (SSU rDNA) of all life. The forest soil was a sink for atmospheric CH4 in situ and in vitro at all times. In winter, atmospheric CH4was oxidized in a well-defined subsurface soil layer (6 to 14 cm deep), whereas in summer, the complete soil core was active (0 cm to 26 cm deep). The content of total extractable DNA was about 10-fold higher in summer than in winter. It decreased with soil depth (0 to 28 cm deep) from about 40 to 1 μg DNA per g (dry weight) of soil. The PCR product concentration of SSU rDNA of all life was constant both in winter and in summer. However, the PCR product concentration of pmoAchanged with depth and season. pmoA was detected only in soil layers with active CH4 oxidation, i.e., 6 to 16 cm deep in winter and throughout the soil core in summer. The same methanotrophic populations were present in winter and summer. Layers with high CH4 consumption rates also exhibited more bands of pmoA in DGGE, indicating that high CH4oxidation activity was positively correlated with the number of methanotrophic populations present. The pmoA sequences derived from excised DGGE bands were only distantly related to those of known methanotrophs, indicating the existence of unknown methanotrophs involved in atmospheric CH4 consumption.
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Sánchez-Carrillo, Salvador, Jaime Garatuza-Payan, Raquel Sánchez-Andrés, Francisco J. Cervantes, María Carmen Bartolomé, Martín Merino-Ibarra, and Frederic Thalasso. "Methane Production and Oxidation in Mangrove Soils Assessed by Stable Isotope Mass Balances." Water 13, no. 13 (July 4, 2021): 1867. http://dx.doi.org/10.3390/w13131867.
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Considerable variability in methane production and emissions has been reported in mangroves, explained by methane inhibition and oxidation. In this study, soil pore waters were collected from mangrove forests located in the Gulf of California (Mexico) exposed to shrimp farm disturbance. The δ13C of dissolved inorganic carbon (DIC) and CH4 were analyzed along with the δ13C of the soil organic matter to assess the proportion of CO2 derived from methanogenesis, its main pathway, and the fraction of methane oxidized. We performed slurry incubation experiments to fit the isotope–mass balance approach. Very low stoichiometric ratios of CH4/CO2 were measured in pore waters, but isotope mass balances revealed that 30–70% of the total CO2 measured was produced by methanogenesis. Mangrove soils receiving effluent discharges shifted the main methanogenesis pathway to CO2 reduction because of an increase in refractory organic matter. Isotope–mass balances of incubations indicated that methane was mainly oxidized by anaerobic oxidation of methane (AOM) coupled to sulfate reduction, and the increase in recalcitrant organic matter should fuel AOM as humus serves as a terminal electron acceptor. Since methanogenesis in mangrove soils is strongly controlled by the oxygen supply provided by mangrove roots, conservation of the forest plays a crucial role in mitigating greenhouse gas emissions.
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Allen, D. E., D. S. Mendham, Bhupinderpal-Singh, A. Cowie, W. Wang, R. C. Dalal, and R. J. Raison. "Nitrous oxide and methane emissions from soil are reduced following afforestation of pasture lands in three contrasting climatic zones." Soil Research 47, no. 5 (2009): 443. http://dx.doi.org/10.1071/sr08151.
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Land use change from agriculture to forestry offers potential opportunities for carbon (C) sequestration and thus partial mitigation of increasing levels of carbon dioxide (CO2) in the atmosphere. The effects of land use change of grazed pastures on in situ fluxes of nitrous oxide (N2O) and methane (CH4) from soil were examined across 3 forest types in Australian temperate, Mediterranean, and subtropical regions, using a network of paired pasture−forest sites, representing 3 key stages of forest stand development: establishment, canopy-closure, and mid to late rotation. During the 12-month study, soil temperature ranged from –6° to 40°C and total rainfall from 487 to 676 mm. Rates of N2O flux ranged between 1 and 100 μg/m2.h in pasture soils and from –5 to 50 μg/m2.h in forest soils; magnitudes were generally similar across the 3 climate zones. Rates of CH4 flux varied from –1 to –50 μg/m2.h in forest soil and from +10 to –30 μg/m2.h in pasture soils; CH4 flux was highest at the subtropics sites and lowest at the Mediterranean sites. In general, N2O emissions were lower, and CH4 consumption was higher, under forest than pasture soils, suggesting that land use change from pasture to forest can have a positive effect on mitigation of non-CO2 greenhouse gas (GHG) emissions from soil as stands become established. The information derived from this study can be used to improve the capacity of models for GHG accounting (e.g. FullCAM, which underpins Australia’s National Carbon Accounting System) to estimate N2O and CH4 fluxes resulting from land use change from pasture to forest in Australia. There is still, however, a need to test model outputs against continuous N2O and CH4 measurements over extended periods of time and across a range of sites with similar land use, to increase confidence in spatial and temporal estimates at regional levels.
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Degelmann, Daniela M., Werner Borken, Harold L. Drake, and Steffen Kolb. "Different Atmospheric Methane-Oxidizing Communities in European Beech and Norway Spruce Soils." Applied and Environmental Microbiology 76, no. 10 (March 26, 2010): 3228–35. http://dx.doi.org/10.1128/aem.02730-09.
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ABSTRACT Norway spruce (Picea abies) forests exhibit lower annual atmospheric methane consumption rates than do European beech (Fagus sylvatica) forests. In the current study, pmoA (encoding a subunit of membrane-bound CH4 monooxygenase) genes from three temperate forest ecosystems with both beech and spruce stands were analyzed to assess the potential effect of tree species on methanotrophic communities. A pmoA sequence difference of 7% at the derived protein level correlated with the species-level distance cutoff value of 3% based on the 16S rRNA gene. Applying this distance cutoff, higher numbers of species-level pmoA genotypes were detected in beech than in spruce soil samples, all affiliating with upland soil cluster α (USCα). Additionally, two deep-branching genotypes (named 6 and 7) were present in various soil samples not affiliating with pmoA or amoA. Abundance of USCα pmoA genes was higher in beech soils and reached up to (1.2 ± 0.2) × 108 pmoA genes per g of dry weight. Calculated atmospheric methane oxidation rates per cell yielded the same trend. However, these values were below the theoretical threshold necessary for facilitating cell maintenance, suggesting that USCα species might require alternative carbon or energy sources to thrive in forest soils. These collective results indicate that the methanotrophic diversity and abundance in spruce soils are lower than those of beech soils, suggesting that tree species-related factors might influence the in situ activity of methanotrophs.
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Bartsch, Annett, Carsten Pathe, Wolfgang Wagner, and Klaus Scipal. "Detection of permanent open water surfaces in central Siberia with ENVISAT ASAR wide swath data with special emphasis on the estimation of methane fluxes from tundra wetlands." Hydrology Research 39, no. 2 (April 1, 2008): 89–100. http://dx.doi.org/10.2166/nh.2008.041.
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Permanent water bodies not only store dissolved CO2 but are essential for the maintenance of wetlands in their proximity. From the viewpoint of greenhouse gas (GHG) accounting wetland functions comprise sequestration of carbon under anaerobic conditions and methane release. The investigated area in central Siberia covers boreal and sub-arctic environments. Small inundated basins are abundant on the sub-arctic Taymir lowlands but also in parts of severe boreal climate where permafrost ice content is high and feature important freshwater ecosystems. Satellite radar imagery (ENVISAT ScanSAR), acquired in summer 2003 and 2004, has been used to derive open water surfaces with 150 m resolution, covering an area of approximately 3 Mkm2. The open water surface maps were derived using a simple threshold-based classification method. The results were assessed with Russian forest inventory data, which includes detailed information about water bodies. The resulting classification has been further used to estimate the extent of tundra wetlands and to determine their importance for methane emissions. Tundra wetlands cover 7% (400 000 km2) of the study region and methane emissions from hydromorphic soils are estimated to be 45 000 t d−1 for the Taymir peninsula.
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Vainio, Elisa, Olli Peltola, Ville Kasurinen, Antti-Jussi Kieloaho, Eeva-Stiina Tuittila, and Mari Pihlatie. "Topography-based statistical modelling reveals high spatial variability and seasonal emission patches in forest floor methane flux." Biogeosciences 18, no. 6 (March 19, 2021): 2003–25. http://dx.doi.org/10.5194/bg-18-2003-2021.
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Abstract. Boreal forest soils are globally an important sink for methane (CH4), while these soils are also capable of emitting CH4 under favourable conditions. Soil wetness is a well-known driver of CH4 flux, and the wetness can be estimated with several terrain indices developed for the purpose. The aim of this study was to quantify the spatial variability of the forest floor CH4 flux with a topography-based upscaling method connecting the flux with its driving factors. We conducted spatially extensive forest floor CH4 flux and soil moisture measurements, complemented by ground vegetation classification, in a boreal pine forest. We then modelled the soil moisture with a random forest model using digital-elevation-model-derived topographic indices, based on which we upscaled the forest floor CH4 flux. The modelling was performed for two seasons: May–July and August–October. Additionally, we evaluated the number of flux measurement points needed to get an accurate estimate of the flux at the whole study site merely by averaging. Our results demonstrate high spatial heterogeneity in the forest floor CH4 flux resulting from the soil moisture variability as well as from the related ground vegetation. The mean measured CH4 flux at the sample points was −5.07 µmol m−2 h−1 in May–July and −8.67 µmol m−2 h−1 in August–October, while the modelled flux for the whole area was −7.42 and −9.91 µmol m−2 h−1 for the two seasons, respectively. The spatial variability in the soil moisture and consequently in the CH4 flux was higher in the early summer (modelled range from −12.3 to 6.19 µmol m−2 h−1) compared to the autumn period (range from −14.6 to −2.12 µmol m−2 h−1), and overall the CH4 uptake rate was higher in autumn compared to early summer. In the early summer there were patches emitting high amounts of CH4; however, these wet patches got drier and smaller in size towards the autumn, changing their dynamics to CH4 uptake. The mean values of the measured and modelled CH4 fluxes for the sample point locations were similar, indicating that the model was able to reproduce the results. For the whole site, upscaling predicted stronger CH4 uptake compared to simply averaging over the sample points. The results highlight the small-scale spatial variability of the boreal forest floor CH4 flux and the importance of soil chamber placement in order to obtain spatially representative CH4 flux results. To predict the CH4 fluxes over large areas more reliably, the locations of the sample points should be selected based on the spatial variability of the driving parameters, in addition to linking the measured fluxes with the parameters.
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Knief, Claudia, André Lipski, and Peter F. Dunfield. "Diversity and Activity of Methanotrophic Bacteria in Different Upland Soils." Applied and Environmental Microbiology 69, no. 11 (November 2003): 6703–14. http://dx.doi.org/10.1128/aem.69.11.6703-6714.2003.
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ABSTRACT Samples from diverse upland soils that oxidize atmospheric methane were characterized with regard to methane oxidation activity and the community composition of methanotrophic bacteria (MB). MB were identified on the basis of the detection and comparative sequence analysis of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. MB commonly detected in soils were closely related to Methylocaldum spp., Methylosinus spp., Methylocystis spp., or the “forest sequence cluster” (USC α), which has previously been detected in upland soils and is related to pmoA sequences of type II MB (Alphaproteobacteria). As well, a novel group of sequences distantly related (<75% derived amino acid identity) to those of known type I MB (Gammaproteobacteria) was often detected. This novel “upland soil cluster γ” (USC γ) was significantly more likely to be detected in soils with pH values of greater than 6.0 than in more acidic soils. To identify active MB, four selected soils were incubated with 13CH4 at low mixing ratios (<50 ppm of volume), and extracted methylated phospholipid fatty acids (PLFAs) were analyzed by gas chromatography-online combustion isotope ratio mass spectrometry. Incorporation of 13C into PLFAs characteristic for methanotrophic Gammaproteobacteria was observed in all soils in which USC γ sequences were detected, suggesting that the bacteria possessing these sequences were active methanotrophs. A pattern of labeled PLFAs typical for methanotrophic Alphaproteobacteria was obtained for a sample in which only USC α sequences were detected. The data indicate that different MB are present and active in different soils that oxidize atmospheric methane.
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Noriyasu, Atsuko, Kohei Otsuka, Yuki Ishizaki, Yutaka Tanaike, Ken Matsuyama, Kazuya Uezu, and Tomonori Kawano. "A Novel Wild-Land Fire-Fighting Foam for Minimizing the Phytotoxicity of Wood Burning-Derived Smoke Tested in Living Plant Cells." Advanced Materials Research 875-877 (February 2014): 725–33. http://dx.doi.org/10.4028/www.scientific.net/amr.875-877.725.
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Impact of wild-land fires to the ecosystem is highly complex. Damages to the ecosystem can be attributed not only to the direct impact of fire and release of toxic post-combustion gasses but also to the spraying of fire-fighting chemicals. Fire-fighting foam (FFF) agents are frequently applied for controls in wild-land fires including forest fire. However, effects of FFFs on the composition of the post-combustion gasses and the phytotoxicity of smoke derived from burning woods have not been determined to date. In the present study, with Fourier transform infrared spectroscopy (FT-IR), we have analyzed the chemical composition of the gasses derived from wood slices exposed to two distinct manners of combustion, namely, smoldering (gradual combustion without flame) and rapid burning (combustion with flame). Tested samples include slices of Japanese cedar, Japanese cypress, and Western hemlock. The amount of hydrocarbons, detected in the post-combustion gas such as methane, ethane, ethylene, propane, hexane, formaldehyde, acrolein and phenol, were higher in the gasses from smoldered samples. The major hydrocarbon found in the post-combustion gases processed in the presence of pilot flame was methane. Other hydrocarbons were hardly detectable. Addition of FFFs, namely, a soap-based FFF (designated as MK-08) and a detergent co cocktail-based FFF (Phos-chek) onto wooden slices resulted in slight increase in other hydrocarbons in the gasses derived from flame-driven combustion of wood slices. Interestingly, addition of Phos-chek drastically elevated the phytotoxicity of post-combustion gas derived from Western hemlock slices heated in the presence of pilot flame when assessed using the suspension cultured tobacco cells. In contrast, the soap-based FFF tested here did not alter the phytotoxicity of the post-combustion gasses, suggesting that soap-based FFF might minimize the impact of the fire-fighting activity to the living plants consisting the ecosystem in the forests and wild-land.
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Monarca, D., A. Colantoni, M. Cecchini, L. Longo, L. Vecchione, M. Carlini, and A. Manzo. "Energy Characterization and Gasification of Biomass Derived by Hazelnut Cultivation: Analysis of Produced Syngas by Gas Chromatography." Mathematical Problems in Engineering 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/102914.
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Modern agriculture is an extremely energy intensive process. However, high agricultural productivities and the growth of green revolution has been possible only by large amount of energy inputs, especially those coming from fossil fuels. These energy resources have not been able to provide an economically viable solution for agricultural applications. Biomass energy-based systems had been extensively used for transportation and on farm systems during World War II: the most common and reliable solution was wood or biomass gasification. The latter means incomplete combustion of biomass resulting in production of combustible gases which mostly consist of carbon monoxide (CO), hydrogen (H2) and traces of methane (CH4). This mixture is called syngas, which can be successfully used to run internal combustion engines (both compression and spark ignition) or as substitute for furnace oil in direct heat applications. The aim of the present paper is to help the experimentation of innovative plants for electric power production using agro-forest biomass derived by hazelnut cultivations. An additional purpose is to point out a connection among the chemical and physical properties of the outgoing syngas by biomass characterization and gas-chromatography analysis.
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Schneising, O., M. Buchwitz, M. Reuter, J. Heymann, H. Bovensmann, and J. P. Burrows. "Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY." Atmospheric Chemistry and Physics 11, no. 6 (March 28, 2011): 2863–80. http://dx.doi.org/10.5194/acp-11-2863-2011.
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Abstract. Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002) was the first and is now with TANSO onboard GOSAT (launch 2009) one of only two satellite instruments currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest. We present long-term SCIAMACHY retrievals (2003–2009) of column-averaged dry air mole fractions of both gases (denoted XCO2 and XCH4) derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR) spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2) of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4) being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics. The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved global annual mean XCO2 increase agrees with CarbonTracker within the error bars (1.80±0.13 ppm yr−1 compared to 1.81±0.09 ppm yr−1). The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3±0.2 ppm for the Northern Hemisphere and 1.4±0.2 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker. An investigation of the boreal forest carbon uptake during the growing season via the analysis of longitudinal gradients shows good agreement between SCIAMACHY and CarbonTracker concerning the overall magnitude of the gradients and their annual variations. The analysis includes a discussion of the relative uptake strengths of the Russian and North American boreal forest regions. The retrieved XCH4 results show that after years of stability, atmospheric methane has started to rise again in recent years which is consistent with surface measurements. The largest increase is observed for the tropics and northern mid- and high-latitudes amounting to about 7.5±1.5 ppb yr−1 since 2007. Due care has been exercised to minimise the influence of detector degradation on the quantitative estimate of this anomaly.
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Wolfe, Glenn M., S. Randy Kawa, Thomas F. Hanisco, Reem A. Hannun, Paul A. Newman, Andrew Swanson, Steve Bailey, et al. "The NASA Carbon Airborne Flux Experiment (CARAFE): instrumentation and methodology." Atmospheric Measurement Techniques 11, no. 3 (March 28, 2018): 1757–76. http://dx.doi.org/10.5194/amt-11-1757-2018.
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Abstract. The exchange of trace gases between the Earth's surface and atmosphere strongly influences atmospheric composition. Airborne eddy covariance can quantify surface fluxes at local to regional scales (1–1000 km), potentially helping to bridge gaps between top-down and bottom-up flux estimates and offering novel insights into biophysical and biogeochemical processes. The NASA Carbon Airborne Flux Experiment (CARAFE) utilizes the NASA C-23 Sherpa aircraft with a suite of commercial and custom instrumentation to acquire fluxes of carbon dioxide, methane, sensible heat, and latent heat at high spatial resolution. Key components of the CARAFE payload are described, including the meteorological, greenhouse gas, water vapor, and surface imaging systems. Continuous wavelet transforms deliver spatially resolved fluxes along aircraft flight tracks. Flux analysis methodology is discussed in depth, with special emphasis on quantification of uncertainties. Typical uncertainties in derived surface fluxes are 40–90 % for a nominal resolution of 2 km or 16–35 % when averaged over a full leg (typically 30–40 km). CARAFE has successfully flown two missions in the eastern US in 2016 and 2017, quantifying fluxes over forest, cropland, wetlands, and water. Preliminary results from these campaigns are presented to highlight the performance of this system.
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Schneising, O., M. Buchwitz, M. Reuter, J. Heymann, H. Bovensmann, and J. P. Burrows. "Long-term analysis of carbon dioxide and methane column-averaged mole fractions retrieved from SCIAMACHY." Atmospheric Chemistry and Physics Discussions 10, no. 11 (November 11, 2010): 27479–522. http://dx.doi.org/10.5194/acpd-10-27479-2010.
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Abstract. Carbon dioxide (CO2) and methane (CH4) are the two most important anthropogenic greenhouse gases contributing to global climate change. SCIAMACHY onboard ENVISAT (launch 2002) was the first and is now together with TANSO onboard GOSAT (launch 2009) the only satellite instrument currently in space whose measurements are sensitive to CO2 and CH4 concentration changes in the lowest atmospheric layers where the variability due to sources and sinks is largest. We present long-term SCIAMACHY retrievals (2003–2009) of column-averaged mole fractions of both gases (denoted XCO2 and XCH4) derived from absorption bands in the near-infrared/shortwave-infrared (NIR/SWIR) spectral region focusing on large-scale features. The results are obtained using an upgraded version (v2) of the retrieval algorithm WFM-DOAS including several improvements, while simultaneously maintaining its high processing speed. The retrieved mole fractions are compared to global model simulations (CarbonTracker XCO2 and TM5 XCH4) being optimised by assimilating highly accurate surface measurements from the NOAA/ESRL network and taking the SCIAMACHY averaging kernels into account. The comparisons address seasonal variations and long-term characteristics. The steady increase of atmospheric carbon dioxide primarily caused by the burning of fossil fuels can be clearly observed with SCIAMACHY globally. The retrieved annual mean XCO2 increase over both hemispheres agrees with CarbonTracker within the error bars but is on average somewhat smaller (1.8 ppm yr−1 compared to 1.9 ppm yr−1). The amplitude of the XCO2 seasonal cycle as retrieved by SCIAMACHY, which is 4.3 ppm for the Northern Hemisphere and 1.4 ppm for the Southern Hemisphere, is on average about 1 ppm larger than for CarbonTracker. An investigation of the boreal forest carbon uptake during the growing season via the analysis of longitudinal gradients shows good agreement between SCIAMACHY and CarbonTracker concerning the overall magnitude of the gradients and their annual variations. The retrieved XCH4 results show that after years of stability, atmospheric methane has started to rise again in recent years which is consistent with surface measurements. The largest increase is observed for the tropics and northern mid- and high-latitudes amounting to about 8 ppb yr−1 since 2007. Due care has been exercised to minimise the influence of detector degradation on the quantitative estimate of this anomaly.
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Smith, T. E. L., C. Paton-Walsh, C. P. Meyer, G. D. Cook, S. W. Maier, J. Russell-Smith, M. J. Wooster, and C. P. Yates. "New emission factors for Australian vegetation fires measured using open-path Fourier transform infrared spectroscopy – Part 2: Australian tropical savanna fires." Atmospheric Chemistry and Physics 14, no. 20 (October 29, 2014): 11335–52. http://dx.doi.org/10.5194/acp-14-11335-2014.
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Abstract. Savanna fires contribute approximately 40–50% of total global annual biomass burning carbon emissions. Recent comparisons of emission factors from different savanna regions have highlighted the need for a regional approach to emission factor development, and better assessment of the drivers of the temporal and spatial variation in emission factors. This paper describes the results of open-path Fourier transform infrared (OP-FTIR) spectroscopic field measurements at 21 fires occurring in the tropical savannas of the Northern~Territory, Australia, within different vegetation assemblages and at different stages of the dry season. Spectra of infrared light passing through a long (22–70 m) open-path through ground-level smoke released from these fires were collected using an infrared lamp and a field-portable FTIR system. The IR spectra were used to retrieve the mole fractions of 14 different gases present within the smoke, and these measurements used to calculate the emission ratios and emission factors of the various gases emitted by the burning. Only a handful of previous emission factor measures are available specifically for the tropical savannas of Australia and here we present the first reported emission factors for methanol, acetic acid, and formic acid for this biome. Given the relatively large sample size, it was possible to study the potential causes of the within-biome variation of the derived emission factors. We find that the emission factors vary substantially between different savanna vegetation assemblages; with a majority of this variation being mirrored by variations in the modified combustion efficiency (MCE) of different vegetation classes. We conclude that a significant majority of the variation in the emission factor for trace gases can be explained by MCE, irrespective of vegetation class, as illustrated by variations in the calculated methane emission factor for different vegetation classes using data sub-set by different combustion efficiencies. Therefore, the selection of emission factors for emissions modelling purposes need not necessarily require detailed fuel type information, if data on MCE (e.g. from future spaceborne total column measurements) or a correlated variable were available. From measurements at 21 fires, we recommend the following emission factors for Australian tropical savanna fires (in grams of gas emitted per kilogram of dry fuel burned), which are our mean measured values: 1674 ± 56 g kg−1 of carbon dioxide; 87 ± 33 g kg−1 of carbon monoxide; 2.1 ± 1.2 g kg−1 of methane; 0.11 ± 0.04 g kg−1 of acetylene; 0.49 ± 0.22 g kg−1 of ethylene; 0.08 ± 0.05 g kg−1 of ethane; 1.57 ± 0.44 g kg−1 of formaldehyde; 1.06 ± 0.87 g kg−1 of methanol; 1.54 ± 0.64 g kg−1 of acetic acid; 0.16 ± 0.07 g kg−1 of formic acid; 0.53 ± 0.31 g kg−1 of hydrogen cyanide; and 0.70 ± 0.36 g kg−1 of ammonia. In a companion paper, similar techniques are used to characterise the emissions from Australian temperate forest fires.
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Lin, Xueju, Malak M. Tfaily, J. Megan Steinweg, Patrick Chanton, Kaitlin Esson, Zamin K. Yang, Jeffrey P. Chanton, William Cooper, Christopher W. Schadt, and Joel E. Kostka. "Microbial Community Stratification Linked to Utilization of Carbohydrates and Phosphorus Limitation in a Boreal Peatland at Marcell Experimental Forest, Minnesota, USA." Applied and Environmental Microbiology 80, no. 11 (March 28, 2014): 3518–30. http://dx.doi.org/10.1128/aem.00205-14.
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ABSTRACTThis study investigated the abundance, distribution, and composition of microbial communities at the watershed scale in a boreal peatland within the Marcell Experimental Forest (MEF), Minnesota, USA. Through a close coupling of next-generation sequencing, biogeochemistry, and advanced analytical chemistry, a biogeochemical hot spot was revealed in the mesotelm (30- to 50-cm depth) as a pronounced shift in microbial community composition in parallel with elevated peat decomposition. The relative abundance ofAcidobacteriaand theSyntrophobacteraceae, including known hydrocarbon-utilizing genera, was positively correlated with carbohydrate and organic acid content, showing a maximum in the mesotelm. The abundance ofArchaea(primarily crenarchaeal groups 1.1c and 1.3) increased with depth, reaching up to 60% of total small-subunit (SSU) rRNA gene sequences in the deep peat below the 75-cm depth. Stable isotope geochemistry and potential rates of methane production paralleled vertical changes in methanogen community composition to indicate a predominance of acetoclastic methanogenesis mediated by theMethanosarcinalesin the mesotelm, while hydrogen-utilizing methanogens predominated in the deeper catotelm. RNA-derived pyrosequence libraries corroborated DNA sequence data to indicate that the above-mentioned microbial groups are metabolically active in the mid-depth zone. Fungi showed a maximum in rRNA gene abundance above the 30-cm depth, which comprised only an average of 0.1% of total bacterial and archaeal rRNA gene abundance, indicating prokaryotic dominance. Ratios of C to P enzyme activities approached 0.5 at the acrotelm and catotelm, indicating phosphorus limitation. In contrast, P limitation pressure appeared to be relieved in the mesotelm, likely due to P solubilization by microbial production of organic acids and C-P lyases. Based on path analysis and the modeling of community spatial turnover, we hypothesize that P limitation outweighs N limitation at MEF, and microbial communities are structured by the dominant shrub,Chamaedaphne calyculata, which may act as a carbon source for major consumers in the peatland.
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Jones, C. E., S. Kato, Y. Nakashima, and Y. Kajii. "A novel fast gas chromatography method for higher time resolution measurements of speciated monoterpenes in air." Atmospheric Measurement Techniques 7, no. 5 (May 15, 2014): 1259–75. http://dx.doi.org/10.5194/amt-7-1259-2014.
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Abstract. Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9-C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in ambient air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C9-C15 BVOC composition of single plant emissions may be characterised within a 14.5 min analysis time. Moreover, in-situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an 11.7 min chromatographic separation time (increasing to 19.7 min when simultaneous quantification of multiple oxygenated C9-C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). These analysis times potentially allow for a twofold to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in-situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC (OBVOC) linalool in ambient air. During this field deployment within a suburban forest ~30 km west of central Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes was 4–5 ppt, and the agreement between Fast-GC and PTR-MS derived total monoterpene mixing ratios was consistent with previous GC/PTR-MS comparisons. The measurement uncertainties associated with the Fast-GC quantification of monoterpenes are ≤ 12%, while larger uncertainties (up to ~25%) are associated with the OBVOC and sesquiterpene measurements.
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Jones, C. E., S. Kato, Y. Nakashima, and Y. Kajii. "A novel Fast Gas Chromatography based technique for higher time resolution measurements of speciated monoterpenes in air." Atmospheric Measurement Techniques Discussions 6, no. 6 (December 17, 2013): 10921–54. http://dx.doi.org/10.5194/amtd-6-10921-2013.
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Abstract. Biogenic emissions supply the largest fraction of non-methane volatile organic compounds (VOC) from the biosphere to the atmospheric boundary layer, and typically comprise a complex mixture of reactive terpenes. Due to this chemical complexity, achieving comprehensive measurements of biogenic VOC (BVOC) in air within a satisfactory time resolution is analytically challenging. To address this, we have developed a novel, fully automated Fast Gas Chromatography (Fast-GC) based technique to provide higher time resolution monitoring of monoterpenes (and selected other C9–C15 terpenes) during plant emission studies and in ambient air. To our knowledge, this is the first study to apply a Fast-GC based separation technique to achieve quantification of terpenes in air. Three chromatography methods have been developed for atmospheric terpene analysis under different sampling scenarios. Each method facilitates chromatographic separation of selected BVOC within a significantly reduced analysis time compared to conventional GC methods, whilst maintaining the ability to quantify individual monoterpene structural isomers. Using this approach, the C10–C15 BVOC composition of single plant emissions may be characterised within a ~ 14 min analysis time. Moreover, in situ quantification of 12 monoterpenes in unpolluted ambient air may be achieved within an ~ 11 min chromatographic separation time (increasing to ~ 19 min when simultaneous quantification of multiple oxygenated C9–C10 terpenoids is required, and/or when concentrations of anthropogenic VOC are significant). This corresponds to a two- to fivefold increase in measurement frequency compared to conventional GC methods. Here we outline the technical details and analytical capability of this chromatographic approach, and present the first in situ Fast-GC observations of 6 monoterpenes and the oxygenated BVOC linalool in ambient air. During this field deployment within a suburban forest ~ 30 km west of central Tokyo, Japan, the Fast-GC limit of detection with respect to monoterpenes was 4–5 ppt, and the agreement between Fast-GC and PTR-MS derived total monoterpene mixing ratios was consistent with previous GC/PTR-MS comparisons. The measurement uncertainties associated with the Fast-GC quantification of monoterpenes are ≤ 10%, while larger uncertainties (up to ~ 25%) are associated with the OBVOC and sesquiterpene measurements.
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Henry, Beverley K., D. Butler, and S. G. Wiedemann. "A life cycle assessment approach to quantifying greenhouse gas emissions from land-use change for beef production in eastern Australia." Rangeland Journal 37, no. 3 (2015): 273. http://dx.doi.org/10.1071/rj14112.
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In life cycle assessment studies, greenhouse gas (GHG) emissions from direct land-use change have been estimated to make a significant contribution to the global warming potential of agricultural products. However, these estimates have a high uncertainty due to the complexity of data requirements and difficulty in attribution of land-use change. This paper presents estimates of GHG emissions from direct land-use change from native woodland to grazing land for two beef production regions in eastern Australia, which were the subject of a multi-impact life cycle assessment study for premium beef production. Spatially- and temporally consistent datasets were derived for areas of forest cover and biomass carbon stocks using published remotely sensed tree-cover data and regionally applicable allometric equations consistent with Australia’s national GHG inventory report. Standard life cycle assessment methodology was used to estimate GHG emissions and removals from direct land-use change attributed to beef production. For the northern-central New South Wales region of Australia estimates ranged from a net emission of 0.03 t CO2-e ha–1 year–1 to net removal of 0.12 t CO2-e ha–1 year–1 using low and high scenarios, respectively, for sequestration in regrowing forests. For the same period (1990–2010), the study region in southern-central Queensland was estimated to have net emissions from land-use change in the range of 0.45–0.25 t CO2-e ha–1 year–1. The difference between regions reflects continuation of higher rates of deforestation in Queensland until strict regulation in 2006 whereas native vegetation protection laws were introduced earlier in New South Wales. On the basis of liveweight produced at the farm-gate, emissions from direct land-use change for 1990–2010 were comparable in magnitude to those from other on-farm sources, which were dominated by enteric methane. However, calculation of land-use change impacts for the Queensland region for a period starting 2006, gave a range from net emissions of 0.11 t CO2-e ha–1 year–1 to net removals of 0.07 t CO2-e ha–1 year–1. This study demonstrated a method for deriving spatially- and temporally consistent datasets to improve estimates for direct land-use change impacts in life cycle assessment. It identified areas of uncertainty, including rates of sequestration in woody regrowth and impacts of land-use change on soil carbon stocks in grazed woodlands, but also showed the potential for direct land-use change to represent a net sink for GHG.
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Urbanski, S. P. "Combustion efficiency and emission factors for US wildfires." Atmospheric Chemistry and Physics Discussions 13, no. 1 (January 3, 2013): 33–78. http://dx.doi.org/10.5194/acpd-13-33-2013.
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Abstract. In the US wildfires and prescribed burning present significant challenges to air regulatory agencies attempting to achieve and maintain compliance with National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations. Wildland fire emission inventories (EI) provide critical inputs for atmospheric chemical transport models used by air regulatory agencies to understand and to predict the impact of fires on air quality. Fire emission factors (EF), which quantify the amount of pollutants released per mass of biomass burned, are essential input for the emission models used to develop EI. Over the past decade substantial progress has been realized in characterizing the composition of fresh biomass burning (BB) smoke and in quantifying BB EF. However, most BB studies of temperate ecosystems have focused on emissions from prescribed burning. Little information is available on EF for wildfires in the temperate forests of the conterminous US. Current emission estimates for US wildfires rely largely on EF measurements from prescribed burns and it is unknown if these fires are a reasonable proxy for wildfires. Over 8 days in August of 2011 we deployed airborne chemistry instruments and sampled emissions from 3 wildfires and a prescribed fire that occurred in mixed conifer forests of the northern Rocky Mountains. We measured the combustion efficiency, quantified as the modified combustion efficiency (MCE), and EF for CO2, CO, and CH4. Our study average values for MCE, EFCO2, EFCO, and EFCH4 were 0.883, 1596 g kg−1, 135 g kg−1, 7.30 g kg−1, respectively. Compared with previous field studies of prescribed fires in similar forest types, the fires sampled in our study had significantly lower MCE and EFCO2 and significantly higher EFCO and EFCH4. An examination of our study and 47 temperate forest prescribed fires from previously published studies shows a clear trend in MCE across US region/fire type: southeast (MCE = 0.933) > southwest (MCE = 0.922) > northwest (MCE = 0.900) > northwest wildfires (MCE = 0.883). The fires sampled in this work burned in areas reported to have moderate to heavy components of standing dead trees and dead down wood due to insect activity and previous fire, but fuel consumption data was not available for any of the fires. However, fuel consumption data was available for 18 prescribed fires reported in the literature. For these 18 fires we found a significant negative correlation (r =-0.83, p-value = 1.7e-5) between MCE and the ratio of heavy fuel (large diameter dead wood and duff) consumption to total fuel consumption. This observation suggests the relatively low MCE measured for the fires in our study resulted from the availability of heavy fuels and conditions that facilitated combustion of these fuels. More generally, our measurements and the comparison with previous studies indicate that fuel composition is an important driver of variability in MCE and EF. This study only measured EF for CO2, CO, and CH4; however, we used our study average MCE to estimate wildfire EF for PM2.5 and 13 other species using EF–MCE linear relationships reported in the literature. The EF we derived for several non-methane organic compounds (NMOC) were substantially larger (by a factor of 1.5 to 4) than the published prescribed fire EF. Wildfire EFPM2.5 estimated in our analysis is approximately twice that reported for temperate forests in a two widely used reviews of BB emission studies. Likewise, western US wildfire PM2.5 emissions reported in a recent national emission inventory are based on an effective EFPM2.5 that is only 40% of that estimated in our study. If the MCE of the fires sampled in this work are representative of the combustion characteristics of wildfires across western US forests then the use of EF based on prescribed fires may result in a significant underestimate of wildfire PM2.5 and NMOC emissions. Given the magnitude of biomass consumed by western US wildfires, the failure to use wildfire appropriate EFPM2.5 has significant implications for the forecasting and management of regional air quality. The contribution of wildfires to NAAQS PM2.5 and Regional Haze may be underestimated by air regulatory agencies.
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Guérette, Elise-Andrée, Clare Paton-Walsh, Maximilien Desservettaz, Thomas E. L. Smith, Liubov Volkova, Christopher J. Weston, and Carl P. Meyer. "Emissions of trace gases from Australian temperate forest fires: emission factors and dependence on modified combustion efficiency." Atmospheric Chemistry and Physics 18, no. 5 (March 14, 2018): 3717–35. http://dx.doi.org/10.5194/acp-18-3717-2018.
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Abstract. We characterised trace gas emissions from Australian temperate forest fires through a mixture of open-path Fourier transform infrared (OP-FTIR) measurements and selective ion flow tube mass spectrometry (SIFT-MS) and White cell FTIR analysis of grab samples. We report emission factors for a total of 25 trace gas species measured in smoke from nine prescribed fires. We find significant dependence on modified combustion efficiency (MCE) for some species, although regional differences indicate that the use of MCE as a proxy may be limited. We also find that the fire-integrated MCE values derived from our in situ on-the-ground open-path measurements are not significantly different from those reported for airborne measurements of smoke from fires in the same ecosystem. We then compare our average emission factors to those measured for temperate forest fires elsewhere (North America) and for fires in another dominant Australian ecosystem (savanna) and find significant differences in both cases. Indeed, we find that although the emission factors of some species agree within 20 %, including those of hydrogen cyanide, ethene, methanol, formaldehyde and 1,3-butadiene, others, such as acetic acid, ethanol, monoterpenes, ammonia, acetonitrile and pyrrole, differ by a factor of 2 or more. This indicates that the use of ecosystem-specific emission factors is warranted for applications involving emissions from Australian forest fires.
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Robinson, N. H., J. F. Hamilton, J. D. Allan, B. Langford, D. E. Oram, Q. Chen, K. Docherty, et al. "Evidence for a significant proportion of Secondary Organic Aerosol from isoprene above a maritime tropical forest." Atmospheric Chemistry and Physics Discussions 10, no. 11 (November 1, 2010): 25545–76. http://dx.doi.org/10.5194/acpd-10-25545-2010.
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Abstract. Isoprene is the most abundant non-methane biogenic volatile organic compound (BVOC), but the processes governing secondary organic aerosol (SOA) formation from isoprene oxidation are only beginning to become understood and selective quantification of the atmospheric particulate burden remains difficult. Organic aerosol above a tropical rainforest located in Danum Valley, Borneo, Malaysia, a high isoprene emission region, was studied during Summer 2008 using Aerosol Mass Spectrometry and offline detailed characterisation using comprehensive two dimensional gas chromatography. Observations indicate that a substantial fraction (up to 15% by mass) of atmospheric sub-micron organic aerosol was observed as methylfuran (MF) after thermal desorption. This observation was associated with the simultaneous measurements of established gas-phase isoprene oxidation products methylvinylketone (MVK) and methacrolein (MACR). Observations of MF were also made during experimental chamber oxidation of isoprene. Positive matrix factorisation of the AMS organic mass spectral time series produced a robust factor which accounts for an average of 23% (0.18 μg m−3), reaching as much as 53% (0.50 μg m−3) of the total oraganic loading, identified by (and highly correlated with) a strong MF signal. Assuming that this factor is generally representative of isoprene SOA, isoprene derived aerosol plays a significant role in the region. Comparisons with measurements from other studies suggest this type of isoprene SOA plays a role in other isoprene dominated environments, albeit with varying significance.
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Robinson, N. H., J. F. Hamilton, J. D. Allan, B. Langford, D. E. Oram, Q. Chen, K. Docherty, et al. "Evidence for a significant proportion of Secondary Organic Aerosol from isoprene above a maritime tropical forest." Atmospheric Chemistry and Physics 11, no. 3 (February 4, 2011): 1039–50. http://dx.doi.org/10.5194/acp-11-1039-2011.
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Abstract. Isoprene is the most abundant non-methane biogenic volatile organic compound (BVOC), but the processes governing secondary organic aerosol (SOA) formation from isoprene oxidation are only beginning to become understood and selective quantification of the atmospheric particulate burden remains difficult. Organic aerosol above a tropical rainforest located in Danum Valley, Borneo, Malaysia, a high isoprene emission region, was studied during Summer 2008 using Aerosol Mass Spectrometry and offline detailed characterisation using comprehensive two dimensional gas chromatography. Observations indicate that a substantial fraction (up to 15% by mass) of atmospheric sub-micron organic aerosol was observed as methylfuran (MF) after thermal desorption. This observation was associated with the simultaneous measurements of established gas-phase isoprene oxidation products methylvinylketone (MVK) and methacrolein (MACR). Observations of MF were also made during experimental chamber oxidation of isoprene. Positive matrix factorisation of the AMS organic mass spectral time series produced a robust factor which accounts for an average of 23% (0.18 μg m−3), reaching as much as 53% (0.50 μg m−3) of the total oraganic loading, identified by (and highly correlated with) a strong MF signal. Assuming that this factor is generally representative of isoprene SOA, isoprene derived aerosol plays a significant role in the region. Comparisons with measurements from other studies suggest this type of isoprene SOA plays a role in other isoprene dominated environments, albeit with varying significance.
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Oliveira, Viviana Maria Araújo de, Ana Lucia Basilio Carneiro, Glaucia Socorro de Barros Cauper, and Adrian Martin Pohlit. "In vitro screening of Amazonian plants for hemolytic activity and inhibition of platelet aggregation in human blood." Acta Amazonica 39, no. 4 (2009): 973–80. http://dx.doi.org/10.1590/s0044-59672009000400026.
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In the present study, different aerial parts from twelve Amazonian plant species found in the National Institute for Amazon Research's (INPA's) Adolpho Ducke Forest Reserve (in Manaus, Amazonas, Brazil) were collected. Separate portions of dried, ground plant materials were extracted with water (by infusion), methanol and chloroform (by continuous liquid-solid extraction) and solvents were removed first by rotary evaporation, and finally by freeze-drying which yielded a total of seventy-one freeze-dried extracts for evaluation. These extracts were evaluated initially at concentrations of 500 and 100 µg/mL for in vitro hemolytic activity and in vitro inhibition of platelet aggregation in human blood, respectively. Sixteen extracts (23 % of all extracts tested, 42 % of all plant species), representing the following plants: Chaunochiton kappleri (Olacaceae), Diclinanona calycina (Annonaceae), Paypayrola grandiflora (Violaceae), Pleurisanthes parviflora (Icacinaceae), Sarcaulus brasiliensis (Sapotaceae), exhibited significant inhibitory activity towards human platelet aggregation. A group of extracts with antiplatelet aggregation activity having no in vitro hemolytic activity has therefore been identified. Three extracts (4 %), all derived from Elaeoluma nuda (Sapotaceae), exhibited hemolytic activity. None of the plant species in this study has known use in traditional medicine. So, these data serve as a baseline or minimum of antiplatelet and hemolytic activities (and potential usefulness) of non-medicinal plants from the Amazon forest. Finally, in general, these are the first data on hemolytic and inhibitory activity on platelet aggregation for the genera which these plant species represent.
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Fang, Mengchan, Fan Liu, Lingling Huang, Liqing Wu, Lan Guo, and Yiqun Wan. "A Urine Metabonomics Study of Rat Bladder Cancer by Combining Gas Chromatography-Mass Spectrometry with Random Forest Algorithm." International Journal of Analytical Chemistry 2020 (September 21, 2020): 1–9. http://dx.doi.org/10.1155/2020/8839215.
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A urine metabolomics study based on gas chromatography-mass spectrometry (GC-MS) and multivariate statistical analysis was applied to distinguish rat bladder cancer. Urine samples with different stages were collected from animal models, i.e., the early stage, medium stage, and advanced stage of the bladder cancer model group and healthy group. After resolving urea with urease, the urine samples were extracted with methanol and, then, derived with N, O-Bis(trimethylsilyl) trifluoroacetamide and trimethylchlorosilane (BSTFA + TMCS, 99 : 1, v/v), before analyzed by GC-MS. Three classification models, i.e., healthy control vs. early- and middle-stage groups, healthy control vs. advanced-stage group, and early- and middle-stage groups vs. advanced-stage group, were established to analyze these experimental data by using Random Forests (RF) algorithm, respectively. The classification results showed that combining random forest algorithm with metabolites characters, the differences caused by the progress of disease could be effectively exhibited. Our results showed that glyceric acid, 2, 3-dihydroxybutanoic acid, N-(oxohexyl)-glycine, and D-turanose had higher contributions in classification of different groups. The pathway analysis results showed that these metabolites had relationships with starch and sucrose, glycine, serine, threonine, and galactose metabolism. Our study results suggested that urine metabolomics was an effective approach for disease diagnosis.
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Sun, Tianran, Juan J. L. Guzman, James D. Seward, Akio Enders, Joseph B. Yavitt, Johannes Lehmann, and Largus T. Angenent. "Suppressing peatland methane production by electron snorkeling through pyrogenic carbon in controlled laboratory incubations." Nature Communications 12, no. 1 (July 5, 2021). http://dx.doi.org/10.1038/s41467-021-24350-y.
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AbstractNorthern peatlands are experiencing more frequent and severe fire events as a result of changing climate conditions. Recent studies show that such a fire-regime change imposes a direct climate-warming impact by emitting large amounts of carbon into the atmosphere. However, the fires also convert parts of the burnt biomass into pyrogenic carbon. Here, we show a potential climate-cooling impact induced by fire-derived pyrogenic carbon in laboratory incubations. We found that the accumulation of pyrogenic carbon reduced post-fire methane production from warm (32 °C) incubated peatland soils by 13–24%. The redox-cycling, capacitive, and conductive electron transfer mechanisms in pyrogenic carbon functioned as an electron snorkel, which facilitated extracellular electron transfer and stimulated soil alternative microbial respiration to suppress methane production. Our results highlight an important, but overlooked, function of pyrogenic carbon in neutralizing forest fire emissions and call for its consideration in the global carbon budget estimation.
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Bramryd, Torleif, and Michael Johansson. "Modern Landfills as Potential Feed Back Processes to Counteract Global Warming." Linnaeus Eco-Tech, July 20, 2017, 780–87. http://dx.doi.org/10.15626/eco-tech.2010.084.
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Provided that produced biogas is effectively collected, landfills are important sinks for organic carbon compensating for emissions of CO2 from burning of fossil fuels. Sequestrating of long-lived organic carbon in the landfill itself is the most pronounced factor, but also other processes during landfill management will increase the capture and binding of CO2.. Compost produced in connection to the landfills and applied as soil improvement, is another important sink for organic carbon.The landfills in the World have been estimated to accumulate around 100 x 106 metric tons of C. Normally about 25-40 percent of the total carbon content in the waste can be converted into biogas in traditional landfills. During landfilling most of the organic carbon in fossil derived products, like plastics, synthetic rubber, textiles and other synthetic materials, As these products take part in the methane gas production, the landfill gas (biogas) can be regarded as a true biofuel. In contrast to incineration, high moisture content in the waste will not decrease the yield of energy per ton of waste. In a reactor landfill treating approximately 100 000 tons of waste per year, a longlived organic fraction corresponding to about 45 000 metric tons of carbon dioxide is longterm accumulated each year. This compensates for the annual carbon dioxide emissions from about 15 000 – 20 000 cars, provided that each one runs 15 000 km per year with fossil fuel. The technique for effective collection of landfill gas, and new techniques to upgrade and liquefy the biogas, have decreased the risk for emissions to the atmosphere. Modern bioreactor landfills have been estimated to have less than 10% diffuse biogas emissions to the atmosphere. Also in Sweden (Helsingborg), plants are built to convert landfill gas to upgraded, liquefied motor fuel. This will lead to strongly reduced diffuse emissions of landfill gas to the atmosphere. The utilization of leachates as forest fertilizer results in an improved biomass production and increased accumulation of soil organic matter. Increased tree and field layer productivity also means that the potential for water evaporation (eg. evapotranspiration) increase, reducing the costs for waste-water treatment or the risk for diffuse ground water pollution. Also in the mineral soil, increased long-lived fractions of humus normally are found. This should be added to the carbon accumulating effect of the landfill itself, where long-lived organic matter, mainly derived from lignin and from fossil fractions as plastics and synthetic textiles is long-term accumulated. In this respect the landfill system has similar effects compared to natural peatlands and lake and sea sediments, Ifproduced biogas is collected effectively, the landfill thus can be an important factor to counteract the “green-house effect” and climate change.
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Morawe, Mareen, Henrike Hoeke, Dirk K. Wissenbach, Guillaume Lentendu, Tesfaye Wubet, Eileen Kröber, and Steffen Kolb. "Acidotolerant Bacteria and Fungi as a Sink of Methanol-Derived Carbon in a Deciduous Forest Soil." Frontiers in Microbiology 8 (July 24, 2017). http://dx.doi.org/10.3389/fmicb.2017.01361.
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