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Emission factors for open and domestic biomass burning for use in atmospheric models
Abstract and Figures
Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially true for non methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New EF should improve regional to global BB emissions estimates and therefore, the input for atmospheric models. In this work we present an up-to-date, comprehensive tabulation of EF for known pyrogenic species based on measurements made in smoke that has cooled to ambient temperature, but not yet undergone significant photochemical processing. All the emission factors are converted to one standard form (g compound emitted per kg dry biomass burned) using the carbon mass balance method and they are categorized into 14 fuel or vegetation types. We compile a large number of measurements of biomass consumption per unit area for important fire types and summarize several recent estimates of global biomass consumption by the major types of biomass burning. Biomass burning terminology is defined to promote consistency. Post emission processes are discussed to provide a context for the emission factor concept within overall atmospheric chemistry and also highlight the potential for rapid changes relative to the scale of some models or remote sensing products. Recent work shows that individual biomass fires emit significantly more gas-phase NMOC than previously thought and that including additional NMOC can improve photochemical model performance. A detailed global estimate suggests that BB emits at least 400 Tg yr−1 of gas-phase NMOC, which is about 4 times larger than most previous estimates. Selected recent results (e.g. measurements of HONO and the BB tracers HCN and CH3CN) are highlighted and key areas requiring future research are briefly discussed.
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... This might have been caused by anthropogenic sources of CO in Thailand, which gave low BC/CO emission ratios in the model (4−6 ng m −3 ppb −1 as shown in Fig. S5d in the supplement). The BC/CO emission ratio calculated from the aircraftbased measurements was also similar to ratios calculated in previous studies, including from an emission factor database (Akagi et al., 2011), when simulated using the WRF-Chem (FINNv1.5) system , from previous airborne observations Warneke et al., 2009), and from observations at a ground-based station with biomass-burning 510 influence (Zhu et al., 2019) (Table S5 in the supplement). ...
Accurate estimates of short-lived climate forcers (SLCFs) emissions are required to allow efficient strategies that mitigate climate change to be developed. However, there remain large uncertainties about emissions of SLCFs from Asia. We identified and improved the constraints of combustion-related emissions of black carbon (BC) and CO using the WRF/CMAQ model (v5.0.2) and the EMeRGe airborne observation data for East Asia in spring 2018. We performed case studies of air masses containing emissions from fires near Thailand and emissions from urban areas in the Philippines and China. Chinese emissions were analysed in depth. Unlike observations at ground-based stations, the observations from aircraft used here would not have been strongly influenced by local emissions and near-surface processes. We confirmed that the GFEDv4.1s inventory provided accurate data for emissions from fires near Thailand. However, anthropogenic BC and CO emissions from the Philippines (REASv2.1) were negatively biased. Marked positive and negative differences were found for BC (+1.62 µg m−3) and CO (−400 ppbv) from the HTAPv2.2z emission inventory for Chinese air masses, consistent with the results of previous ground-based studies. The Chinese BC/CO emission ratio, 3.5±0.1 ng m−3 ppb−1, calculated using data from airborne observations in the altitude range ~0.3–1 km also agreed with the ground-based results. Linearly scaling BC emissions using an observation/model ratio (E(BC) = 0.48±0.13) gave our best estimate of 0.65±0.25 (Tg BC) yr-1. The calculated BC/CO and CO/CO2 ratios led us to estimate that emissions from China are 166±65 (Tg CO) yr-1 and 12.4±4.8 (Pg CO2) yr-1. The results suggested that downward and upward revisions of Chinese emissions of BC (−50 %) and CO (+20 %), respectively, are required in HTAPv2.2z emission inventory.
... First, we conduct several sensitivity simulations with 4°× 5°GEOS-Chem to investigate the impacts of fire. Then, we calculate the mass of monthly total fire-induced HCHO (m HCHO ; Equation 7) based on the mass (m) of burned dry matter from different land cover types (i), which is provided by GFED4s inventory, and emission factors (k) to HCHO documented in Akagi et al. (2011). These emission factors are measured after smoke cooled down to ambient temperature without undergoing significant photochemical processes. ...
Satellite column formaldehyde (HCHO) is an indicator of regional volatile organic compounds (VOC) emissions as HCHO is a short‐lived intermediate oxidation product. The Geostationary Environment Monitoring Spectrometer (GEMS), launched in 2020, is the first geostationary satellite to monitor hourly HCHO. GEMS offers unprecedented potential to reveal the diurnal variations of VOC emissions in Asia. Here, we present the first study to evaluate year‐round GEMS HCHO retrievals using TROPOMI satellite and ground‐based Pandora spectrometers. Our study shows that GEMS HCHO aligns with TROPOMI (r = 0.59–0.85; differences within 20% for most areas). Moreover, GEMS captures monthly and diurnal HCHO variations observed by Pandora spectrometers across Asia with differences overall within 15% (r ∼ 0.85). Diurnally, we find strong HCHO variations over urban areas but not in forests. During the fire season of mainland Southeast Asia, GEMS HCHO increases in the afternoon, in line with diurnal emission estimates from the Global Fire Emissions Database Version 4 with small fires (GFED4s) and GEOS‐Chem simulations. GEMS also captures the spatial patterns of fire emissions in GFED4s. GEMS HCHO shows negative bias when observing with a high (>60°) viewing zenith angle (VZA) and overly relies on model correction for observations to the north of 30°N.
... The HCs and CH3Cl shown in Fig. 6 are known to be emitted by biomass burning (Mauzerall et al., 1998;Blake et al., 1999;Akagi et al., 2011;Santee et al., 2013;Andreae, 2019). In all instances, HCs and CH3Cl were positively correlated with CO and CH4, but C2Cl4, a tracer of urban origin, remained unchanged. ...
Recent studies hypothesize that emissions from fires reaching the stratosphere can provide aerosols and aerosol precursors that initiate stratospheric ozone loss and lead to radiative heating of the stratosphere and cooling of the surface. Air from the troposphere enters the stratosphere primarily over the tropical western Pacific (TWP) during boreal winter. We report observations in the TWP of persistent, ubiquitous continental pollution in the tropical tropopause layer (TTL) and lower stratosphere (LS) during the Airborne Tropical TRopopause EXperiment (ATTREX) campaign in February–March 2014. We found concentrations of carbon monoxide (CO) enhanced up to 65 % over background levels in the deep tropics (5° S–15° N, 16 –17 km). Correlations of CO with hydrocarbon and halocarbon species indicated a biomass burning source, with the largest CO enhancements found in warmer, clear air. Satellite observations of CO did not detect the thin pollution layers observed by the aircraft, but did indicate Africa, Indonesia, and the western/central Pacific as geographical hot spots for CO in the TTL. Backward trajectories identified convective encounters in these areas as the dominant sources of polluted air in the TWP. Africa and Indonesia contributed about 60 % of the excess CO, transported to the TWP in two to four weeks. Our study confirms that air in the TTL over the TWP is affected by emissions from distant fires that can rapidly reach the LS in the principal source region for air entering the stratosphere, supporting the view that fires in tropical regions could impact stratospheric ozone and temperatures.
Fire is regarded as an essential climate variable, emitting greenhouse gases in the combustion process. Current global assessments of fire emissions traditionally rely on coarse remotely sensed burned-area data, along with biome-specific combustion completeness and emission factors (EFs). However, large uncertainties persist regarding burned areas, biomass affected, and emission factors. Recent increases in resolution have improved previous estimates of burned areas and aboveground biomass while increasing the information content used to derive emission factors, complemented by airborne sensors deployed in the tropics. To date, temperate forests, characterized by a lower fire incidence and stricter aerial surveillance restrictions near wildfires, have received less attention. In this study, we leveraged the distinctive fire season of 2022, which impacted western European temperate forests, to investigate fire emissions monitored by the atmospheric tower network. We examined the role of soil smoldering combustion responsible for higher carbon emissions, locally reported by firefighters but not accounted for in temperate fire emission budgets. We assessed the CO/CO2 ratio released by major fires in the Mediterranean, Atlantic pine, and Atlantic temperate forests of France. Our findings revealed low modified combustion efficiency (MCE) for the two Atlantic temperate regions, supporting the assumption of heavy smoldering combustion. This type of combustion was associated with specific fire characteristics, such as long-lasting thermal fire signals, and affected ecosystems encompassing needle leaf species, peatlands, and superficial lignite deposits in the soils. Thanks to high-resolution data (approximately 10 m) on burned areas, tree biomass, peatlands, and soil organic matter (SOM), we proposed a revised combustion emission framework consistent with the observed MCEs. Our estimates revealed that 6.15 Mt CO2 (±2.65) was emitted, with belowground stock accounting for 51.75 % (±16.05). Additionally, we calculated a total emission of 1.14 Mt CO (±0.61), with 84.85 % (±3.75) originating from belowground combustion. As a result, the carbon emissions from the 2022 fires in France amounted to 7.95 MtCO2-eq (±3.62). These values exceed by 2-fold the Global Fire Assimilation System (GFAS) estimates for the country, reaching 4.18 MtCO2-eq (CO and CO2). Fires represent 1.97 % (±0.89) of the country's annual carbon footprint, corresponding to a reduction of 30 % in the forest carbon sink this year. Consequently, we conclude that current European fire emission estimates should be revised to account for soil combustion in temperate forests. We also recommend the use of atmospheric mixing ratios as an effective monitoring system of prolonged soil fires that have the potential to re-ignite in the following weeks.
Trace gases and aerosols play a fundamental role for climate and air quality, yet predicting their ambient distributions remains challenging, particularly in urban environments. Primary and secondary sources of trace gases and aerosols in the urban atmosphere are diverse and dominated by combustion sources (e.g. traffic or residential energy use), direct emissions (e.g. solvents), or secondary formation processes (e.g. gas to particle conversion). Novel instrumentation is needed to better constrain the fate of these species. With the advance of chemical ionisation mass spectrometry it is now possible to quantify a range of important atmospheric species. Here we use selected volatile organic compound (VOC) and organic aerosol (OA) observations obtained by PTR-TOF-MS and CHARON PTR-TOF-MS technology to decipher chemical source signatures in the urban area of Innsbruck. Chemically speciated gas phase and aerosol measurements were analyzed using positive matrix factorization, suggesting an externally mixed aerosol population with characteristic source contributions from domestic biomass burning, traffic, secondary sources from atmospheric oxidation, gas-fired furnaces and possibly from aircraft operations. We identified specific ions in the mass spectra associated with biomass burning, (e.g. levoglucosan (C6H10O5.H⁺ and fragment ions), furan (C4H4O.H⁺), methyl furans (C5H6O.H⁺), benzene (C6H6.H⁺) and polycyclic aromatic hydrocarbons (C10H8.H⁺)) that were elevated after the passage of a cold front leading to increased domestic biomass burning activities. Overall, the influence of biomass burning on PM1 (particulate matter <1 μm) is heavily dependent on meteorology as wood operated fireplaces are predominantly used as additional heating in the residential sector. Our observations show that the cumulative number density of fine particulate (CFP) matter (defined as 190–1357 nm) was dominated by secondary (e.g. photochemically aged) sources with contributions from primary sources such as traffic, local primary sources and biomass burning, whilethe traffic sector contributes notably to ultrafine particulate matter (UFP) (<90 nm). In addition, a second source of ultrafine particulate matter was identified in the west sector, which includes likely emissions from a nearby airport and/or a gas-fired district heating plant.
Air quality issues are of remarkable interest due to the relevant number of people affected; in the case of ground-level aviation emissions many inventories exist but several degrees of uncertainty, mostly related to the intrinsic variability of aircraft operations and environmental factors, can be highlighted. Via an interdisciplinary-to-transdisciplinary approach accounting for various disciplines, such as Atmospheric Physics, Earth Sciences and Aeronautical procedures, this research paper provides a new insight on the above mentioned uncertainties and calls for more attention be focused on airport air quality measurements and evaluations.
Atmospheric aerosols significantly impact Earth’s climate and air quality. In addition to their number and mass concentrations, their chemical composition influences their environmental and health effects. This study examines global trends in aerosol composition from 2000 to 2020, using the EMAC atmospheric chemistry-climate model and a variety of observational datasets. These include PM2.5 data from regional networks and 744 PM1 datasets from AMS field campaigns conducted at 169 sites worldwide. Results show that organic aerosol (OA) is the dominant fine aerosol component in all continental regions, particularly in areas with significant biomass burning and biogenic VOC emissions. EMAC effectively reproduces the prevalence of secondary OA but underestimates the aging of OA in some cases, revealing uncertainties in distinguishing fresh and aged SOA. While sulfate is a major aerosol component in filter-based observations, AMS and model results indicate nitrate predominates in Europe and Eastern Asia. Mineral dust also plays a critical role in specific regions, as highlighted by EMAC. The study identifies substantial declines in sulfate, nitrate, and ammonium concentrations in Europe and North America, attributed to emission controls, with varying accuracy in model predictions. In Eastern Asia, sulfate reductions due to SO2 controls are partially captured by the model. OA trends differ between methodologies, with filter data showing slight decreases, while AMS data and model simulations suggest slight increases in PM1 OA across Europe, North America, and Eastern Asia. This research underscores the need for integrating advanced models and diverse datasets to better understand aerosol trends and guide environmental policy.
The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions from open burning of biomass, which includes wildfire, agricultural fires, and prescribed burning and does not include biofuel use and trash burning. Emission factors used in the calculations have been updated with recent data, particularly for the non-methane organic compounds (NMOC). The resulting global annual NMOC emission estimates are as much as a factor of 5 greater than some prior estimates. Chemical speciation profiles, necessary to allocate the total NMOC emission estimates to lumped species for use by chemical transport models, are provided for three widely used chemical mechanisms: SAPRC99, GEOS-CHEM, and MOZART-4. Using these profiles, FINNv1 also provides global estimates of key organic compounds, including formaldehyde and methanol. The uncertainty in the FINNv1 emission estimates are about a factor of two; but, the estimates agree closely with other global inventories of biomass burning emissions for CO, CO2, and other species with less variable emission factors. FINNv1 emission estimates have been developed specifically for modeling atmospheric chemistry and air quality in a consistent framework at scales from local to global. The product is unique because of the high temporal and spatial resolution, global coverage, and the number of species estimated. FINNv1 can be used for both hindcast and forecast or near-real time model applications and the results are being critically evaluated with models and observations whenever possible.
This comprehensive volume is the first to consider biomass burning as a global phenomenon and to assess its impact on the atmosphere, on climate, and on the biosphere itself.
The burning of biomass - forests, grasslands, and agricultural fields after the harvest - is much more widespread and extensive than previously believed; most biomass burning is thought to be initiated by humans and is on the increase. This comprehensive volume is the first to consider biomass burning as a global phenomenon and to assess its impact on the atmosphere, on climate, and on the biosphere itself. The 63 chapters by 158 scientists - including leading biomass burn researchers from third-world countries, such as Brazil, Nigeria, Zaire, India, and China, where biomass burning is so prevalent - point to biomass burning as a significant driver of global change on our planet. Global Biomass Burning provides a convenient and current reference on such topics as the remote sensing of biomass burning from space, the geographical distribution of burning; the combustion products of burning in tropical, temperate, and boreal ecosystems; burning as a global source of atmospheric gases and particulates; the impact of biomass burning gases and particulates on global climate; and the role of biomass burning on biodiversity and past global extinctions. Also included are contributions on the importance of biomass burning from the International Geosphere-Biosphere Program: A Study of Global Change and from the International Global Atmospheric Chemistry Project, as well as policy options prepared by the U.S. Environmental Protection Agency for managing biomass burning to mitigate global climate change.
Joel S. Levine is Senior Research Scientist in the Atmospheric Sciences Division, NASA Langley Research Center and is the Principal Investigator of NASA's research program on global biomass burning, Biospheric Research Program, Office of Space Sciences and Applications.
This comprehensive volume is the first to consider biomass burning as a global phenomenon and to assess its impact on the atmosphere, on climate, and on the biosphere itself.
The burning of biomass - forests, grasslands, and agricultural fields after the harvest - is much more widespread and extensive than previously believed; most biomass burning is thought to be initiated by humans and is on the increase. This comprehensive volume is the first to consider biomass burning as a global phenomenon and to assess its impact on the atmosphere, on climate, and on the biosphere itself. The 63 chapters by 158 scientists - including leading biomass burn researchers from third-world countries, such as Brazil, Nigeria, Zaire, India, and China, where biomass burning is so prevalent - point to biomass burning as a significant driver of global change on our planet. Global Biomass Burning provides a convenient and current reference on such topics as the remote sensing of biomass burning from space, the geographical distribution of burning; the combustion products of burning in tropical, temperate, and boreal ecosystems; burning as a global source of atmospheric gases and particulates; the impact of biomass burning gases and particulates on global climate; and the role of biomass burning on biodiversity and past global extinctions. Also included are contributions on the importance of biomass burning from the International Geosphere-Biosphere Program: A Study of Global Change and from the International Global Atmospheric Chemistry Project, as well as policy options prepared by the U.S. Environmental Protection Agency for managing biomass burning to mitigate global climate change.
Joel S. Levine is Senior Research Scientist in the Atmospheric Sciences Division, NASA Langley Research Center and is the Principal Investigator of NASA's research program on global biomass burning, Biospheric Research Program, Office of Space Sciences and Applications.
As we reach the turn of the millennium, the disparity between developed and developing world is of increasing concern. Labour, Poverty, and Development brings together a worldwide mix of contributors from both the academic and practitioner sides of the current debate, combining rigorous economic analysis and broader-based theorizing to provide a detailed picture of the causes, effects, and implications of the current situation in the developing world. All the contributions stress the vertical relationship between macro trends and micro functionings of markets. Part I deals with the interaction between employment and growth and trade policy, investigating the positive relationship betwen growth and emplyment, and the connection between trade liberalization and better working conditions. Part II looks at the situation in urban areas: the crucial and often hidden role that the informal sector plays in the urban employment market and its connection to the formal labour sector, and the collective decision-making involved in gender differentials in education. Finally, Part III investigates the other side of the ruralurban divide, with a detailed micro-study of labour supply in rural communes in China, and an analysis of a common developing-world poverty trap: the spiralling relationship between destitution and low productivity.
Rain forest covers at the most 9% of tropical Africa (Bourlière 1973, p. 280). As a consequence, comparatively little attention is paid to the rain forest in general studies of the vegetation of tropical Africa. Two important books, however, focussed attention on the African rain forest (Fig. 11.1), one by Aubréville (Climats, Forêts et Désertification de l’Afrique tropicale, 1949), and the other by Hedberg and Hedberg (Conservation of Vegetation in Africa, South of the Sahara, 1968). In both, the data are arranged by countries. In addition, a small book by Hopkins called Forest and Savanna (1965) provides an outstanding introduction to west Africa, in particular and Volumes 3 and 4 of Introduction à la Phytogéographie des Pays Tropicaux by Schnell (1976–1977) are an indispensable source of compiled data. The Netherlands were the last among the West European countries to start research on the tropical African rain forest — in 1955, at Wageningen, though a number of fine Dutch publications have appeared since then. I should add that the series of papers edited by Meggers in 1973 (Tropical Forest Ecosystems in Africa and South America), are excellent though on the whole are more of a biogeographic than ecological nature. This series includes the fauna which, unlike the flora, is as diversified as anywhere in the tropics.
The budgets of O3, NOx (NO+NO2), reactive nitrogen (NOy ), and acetic acid in the 0.6km column over weastern Alaska in summer are examined by photochemical modelling of aircraft and ground-based measurements from the Arctic Boundary Layer Expedition (ABLE 3A). It is found that concentrations of O3 in the region are regulated mainly by input from the stratosphere, and losses of comparable magnitude from photochemistry and deposition. The concentrations of NOx(10-50 ppt) are sufficiently high to slow down O3 photochemical loss appreciably relative to a NOx-free atmosphere. Decomposition of peroxyacetyl nitrate (PAN) can account for most of the NOx below 4km altitude, but for only 20% at 6km altitude. Decomposition of other organic nitrates might supply the missing source of NOx. Only 30% of the acetic acid concentrations measured during ABLE 3A can be accounted for by reactions of CH3CO3 with HO2 and CH3O2. There remains a major unidentified source of acetic acid in the atmosphere. -from Authors
