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.
Estimates of biomass burning in Asia are developed to facilitate the modeling of Asian and global air quality. A survey of national, regional, and international publications on biomass burning is conducted to yield consensus estimates of “typical” (i.e., non‐year‐specific) estimates of open burning (excluding biofuels). We conclude that 730 Tg of biomass are burned in a typical year from both anthropogenic and natural causes. Forest burning comprises 45% of the total, the burning of crop residues in the field comprises 34%, and 20% comes from the burning of grassland and savanna. China contributes 25% of the total, India 18%, Indonesia 13%, and Myanmar 8%. Regionally, forest burning in Southeast Asia dominates. National, annual totals are converted to daily and monthly estimates at 1° × 1° spatial resolution using distributions based on AVHRR fire counts for 1999–2000. Several adjustment schemes are applied to correct for the deficiencies of AVHRR data, including the use of moving averages, normalization, TOMS Aerosol Index, and masks for dust, clouds, landcover, and other fire sources. Good agreement between the national estimates of biomass burning and adjusted fire counts is obtained (R 2 = 0.71–0.78). Biomass burning amounts are converted to atmospheric emissions, yielding the following estimates: 0.37 Tg of SO 2 , 2.8 Tg of NO x , 1100 Tg of CO 2 , 67 Tg of CO, 3.1 Tg of CH 4 , 12 Tg of NMVOC, 0.45 Tg of BC, 3.3 Tg of OC, and 0.92 Tg of NH 3 . Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of ±65% for CO 2 emissions in Japan to a high of ±700% for BC emissions in India.
Abstract Obtaining a burning plasma is a critical step towards self-sustaining fusion energy 1 . A burning plasma is one in which the fusion reactions themselves are the primary source of heating in the plasma, which is necessary to sustain and propagate the burn, enabling high energy gain. After decades of fusion research, here we achieve a burning-plasma state in the laboratory. These experiments were conducted at the US National Ignition Facility, a laser facility delivering up to 1.9 megajoules of energy in pulses with peak powers up to 500 terawatts. We use the lasers to generate X-rays in a radiation cavity to indirectly drive a fuel-containing capsule via the X-ray ablation pressure, which results in the implosion process compressing and heating the fuel via mechanical work. The burning-plasma state was created using a strategy to increase the spatial scale of the capsule 2,3 through two different implosion concepts 4–7 . These experiments show fusion self-heating in excess of the mechanical work injected into the implosions, satisfying several burning-plasma metrics 3,8 . Additionally, we describe a subset of experiments that appear to have crossed the static self-heating boundary, where fusion heating surpasses the energy losses from radiation and conduction. These results provide an opportunity to study α-particle-dominated plasmas and burning-plasma physics in the laboratory.
A source apportionment study was performed for particulate matter in the small village of Roveredo, Switzerland, where more than 70% of the households use wood burning for heating purposes. A two-lane trans-Alpine highway passes through the village and contributes to the total aerosol burden in the area. The village is located in a steep Alpine valley characterized by strong and persistent temperature inversions during winter, especially from December to February. During two winter and one early spring campaigns, a seven-wavelength aethalometer, high volume (HIVOL) samplers, an Aerodyne quadrupole aerosol mass spectrometer (AMS), an optical particle counter (OPC), and a Sunset Laboratory OCEC analyzer were deployed to study the contribution of wood burning and traffic aerosols to particulate matter. A linear regression model of the carbonaceous particulate mass in the submicrometer size range CM(PM1) as a function of aerosol light absorption properties measured by the aethalometer is introduced to estimate the particulate mass from wood burning and traffic (PM(wb), PM(traffic)). This model was calibrated with analyses from the 14C method using HIVOL filter measurements. These results indicate that light absorption exponents of 1.1 for traffic and 1.8-1.9 for wood burning calculated from the light absorption at 470 and 950 nanometers should be used to obtain agreement of the two methods regarding the relative wood burning and traffic emission contributions to CM(PM1) and also to black carbon. The resulting PM(wb) and PM(traffic) values explain 86% of the variance of the CM(PM1) and contribute, on average, 88 and 12% to CM(PM1), respectively. The black carbon is estimated to be 51% due to wood burning and 49% due to traffic emissions. The average organic carbon/total carbon (OC/TC) values were estimated to be 0.52 for traffic and 0.88 for wood burning particulate emissions.
Abstract. Biomass burning, the largest global source of elemental carbon (EC) and primary organic carbon (OC), is strongly associated with many subjects of great scientific concern, such as secondary organic aerosol and brown carbon which exert important effects on the environment and on climate in particular. This study investigated the relationships between levoglucosan and other biomass burning tracers (i.e., water soluble potassium and mannosan) based on both ambient samples collected in Beijing and source samples. Compared with North America and Europe, Beijing was characterized by high ambient levoglucosan concentrations and low winter to summer ratios of levoglucosan, indicating significant impact of biomass burning activities throughout the year in Beijing. Comparison of levoglucosan and water soluble potassium (K+) levels suggested that it was acceptable to use K+ as a biomass burning tracer during summer in Beijing, while the contribution of fireworks to K+ could be significant during winter. Moreover, the levoglucosan to K+ ratio was found to be lower during the typical summer period (0.21 ± 0.16) compared with the typical winter period (0.51 ± 0.15). Levoglucosan correlated strongly with mannosan (R2 = 0.97) throughout the winter and the levoglucosan to mannosan ratio averaged 9.49 ± 1.63, whereas levoglucosan and mannosan exhibited relatively weak correlation (R2 = 0.73) during the typical summer period when the levoglucosan to mannosan ratio averaged 12.65 ± 3.38. Results from positive matrix factorization (PMF) model analysis showed that about 50% of the OC and EC in Beijing were associated with biomass burning processes. In addition, a new source identification method was developed based on the comparison of the levoglucosan to K+ ratio and the levoglucosan to mannosan ratio among different types of biomass. Using this method, the major source of biomass burning aerosol in Beijing was suggested to be the combustion of crop residuals, while the contribution from softwood burning was also non-negligible, especially in winter.
Abstract. Biomass burning represents an important source of atmospheric aerosols and greenhouse gases, yet little is known about its interannual variability or the underlying mechanisms regulating this variability at continental to global scales. Here we investigated fire emissions during the 8 year period from 1997 to 2004 using satellite data and the CASA biogeochemical model. Burned area from 2001–2004 was derived using newly available active fire and 500 m. burned area datasets from MODIS following the approach described by Giglio et al. (2006). ATSR and VIRS satellite data were used to extend the burned area time series back in time through 1997. In our analysis we estimated fuel loads, including organic soil layer and peatland fuels, and the net flux from terrestrial ecosystems as the balance between net primary production (NPP), heterotrophic respiration (Rh), and biomass burning, using time varying inputs of precipitation (PPT), temperature, solar radiation, and satellite-derived fractional absorbed photosynthetically active radiation (fAPAR). For the 1997–2004 period, we found that on average approximately 58 Pg C year−1 was fixed by plants as NPP, and approximately 95% of this was returned back to the atmosphere via Rh. Another 4%, or 2.5 Pg C year−1 was emitted by biomass burning; the remainder consisted of losses from fuel wood collection and subsequent burning. At a global scale, burned area and total fire emissions were largely decoupled from year to year. Total carbon emissions tracked burning in forested areas (including deforestation fires in the tropics), whereas burned area was largely controlled by savanna fires that responded to different environmental and human factors. Biomass burning emissions showed large interannual variability with a range of more than 1 Pg C year−1, with a maximum in 1998 (3.2 Pg C year−1) and a minimum in 2000 (2.0 Pg C year−1).
Topics discussed at the March 1990 American Geophysical Union's Conference on biomass burning which was attended by more than 175 participants representing 19 countries are presented. Conference highlights include discussion of remote sensing data concerning biomass burning (BB), gaseous and particle emissions resulting from BB in the tropics, BB in temperate and boreal ecosystems, the historic and prehistoric perspectives on BB, BB and global budgets for carbon, nitrogen, and oxygen, and the BB and the greenhouse effect. Global estimates of annual amounts of biomass burning and of the resulting release of carbon to the atmosphere and the mean gaseous emission ratios for fires in wetlands, chaparral, and boreal ecosystems are given. An overview is presented of some conference discussions including global burning from 1850-1980, the global impact of biomass burning, the great Chinese/Soviet fire of 1987, and burning and biogenic emissions.
Abstract. The last decade has seen tremendous advances in atmospheric aerosol particle research that is often performed in the context of climate and global change science. Biomass burning, one of the largest sources of accumulation mode particles globally, has been closely studied for its radiative, geochemical, and dynamic impacts. These studies have taken many forms including laboratory burns, in situ experiments, remote sensing, and modeling. While the differing perspectives of these studies have ultimately improved our qualitative understanding of biomass-burning issues, the varied nature of the work make inter-comparisons and resolutions of some specific issues difficult. In short, the literature base has become a milieu of small pieces of the biomass-burning puzzle. This manuscript, the second part of four, examines the properties of biomass-burning particle emissions. Here we review and discuss the literature concerning the measurement of smoke particle size, chemistry, thermodynamic properties, and emission factors. Where appropriate, critiques of measurement techniques are presented. We show that very large differences in measured particle properties have appeared in the literature, in particular with regards to particle carbon budgets. We investigate emissions uncertainties using scale analyses, which shows that while emission factors for grass and brush are relatively well known, very large uncertainties still exist in emission factors of boreal, temperate and some tropical forests. Based on an uncertainty analysis of the community data set of biomass burning measurements, we present simplified models for particle size and emission factors. We close this review paper with a discussion of the community experimental data, point to lapses in the data set, and prioritize future research topics.
India, the second largest agro-based economy with year-round crop cultivation, generates a large amount of agricultural waste, including crop residues. In the absence of adequate sustainable management practices, approximately 92 seems a very small number of metric tons of crop waste is burned every year in India, causing excessive particulate matter emissions and air pollution. Crop residue burning has become a major environmental problem causing health issues as well as contributing to global warming. Composting, biochar production and mechanization are a few effective sustainable techniques that can help to curtail the issue while retaining the nutrients present in the crop residue in the soil. The government of India has attempted to curtail this problem, through numerous measures and campaigns designed to promote sustainable management methods such as converting crop residue into energy. However, the alarming rise of air pollution levels caused by crop residue burning in the city of Delhi and other northern areas in India observed in recent years, especially in and after the year of 2015, suggest that the issues is not yet under control. The solution to crop residue burning lies in the effective implementation of sustainable management practices with Government interventions and policies. This manuscript addresses the underlying technical as well as policy issues that has prevented India from achieving a long-lasting solution and also potential solutions that have been overlooked. However, effective implementation of these techniques also requires us to look at other socioeconomic aspects that had not been considered. This manuscript also discusses some of the policy considerations and functionality based on the analyses and current practices. The agricultural waste sector can benefit immensely from some of the examples from other waste sectors such as the municipal solid waste (MSW) and wastewater management where collection, segregation, recycling and disposal are institutionalized to secure an operational system. Active stakeholder involvement including education and empowerment of farmers along with technical solutions and product manufacturing can also assist tremendously. Even though the issue of crop residue burning touches many sectors, such as environment, agriculture, economy, social aspects, education, and energy, the past governmental efforts mainly revolved around agriculture and energy. This sectorial thinking is another barrier that needs to be broken. The government of India as well as governments of other developing countries can benefit from the emerging concept of nexus thinking in managing environmental resources. Nexus thinking promotes a higher-level integration and higher level of stakeholder involvement that goes beyond the disciplinary boundaries, providing a supporting platform to solve issues such as crop residue burning.
Abstract. 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. Uncertainties in the emissions estimates arise from several of the method steps. The use of fire hot spots, assumed area burned, land cover maps, biomass consumption estimates, and emission factors all introduce error into the model estimates. The uncertainty in the FINNv1 emission estimates are about a factor of two; but, the global estimates agree reasonably well 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.
Abstract. Because of its wide coverage over much of the globe, biomass burning has been widely studied in the context of direct radiative forcing. Such study is warranted as smoke particles scatter and at times absorb solar radiation efficiently. Further, as much of what is known about smoke transport and impacts is based on remote sensing measurements, the optical properties of smoke particles have far reaching effects into numerous aspects of biomass burning studies. Global estimates of direct forcing have been widely varying, ranging from near zero to −1 W m-2. A significant part of this difference can be traced to varying assumptions on the optical properties of smoke. This manuscript is the third part of four examining biomass-burning emissions. Here we review and discuss the literature concerning measurement and modeling of optical properties of biomass-burning particles. These include available data from published sensitivity studies, field campaigns, and inversions from the Aerosol Robotic Network (AERONET) of Sun photometer sites. As a whole, optical properties reported in the literature are varied, reflecting both the dynamic nature of fires, variations in smoke aging processes and differences in measurement technique. We find that forward modeling or ''internal closure'' studies ultimately are of little help in resolving outstanding measurement issues due to the high degree of degeneracy in solutions when using ''reasonable'' input parameters. This is particularly notable with respect to index of refraction and the treatment of black carbon. Consequently, previous claims of column closure may in fact be more ambiguous. Differences between in situ and retrieved ωo values have implications for estimates of mass scattering and mass absorption efficiencies. In this manuscript we review and discuss this community dataset. Strengths and lapses are pointed out, future research topics are prioritized, and best estimates and uncertainties of key smoke particle parameters are provided.
We present an assessment of biofuel use and agricultural field burning in the developing world. We used information from government statistics, energy assessments from the World Bank, and many technical reports, as well as from discussions with experts in agronomy, forestry, and agro‐industries. We estimate that 2060 Tg biomass fuel was used in the developing world in 1985; of this, 66% was burned in Asia, and 21% and 13% in Africa and Latin America, respectively. Agricultural waste supplies about 33% of total biofuel use, providing 39%, 29%, and 13% of biofuel use in Asia, Latin America, and Africa, and 41% and 51% of the biofuel use in India and China. We find that 400 Tg of crop residues are burned in the fields, with the fraction of available residue burned in 1985 ranging from 1% in China, 16–30% in the Middle East and India, to about 70% in Indonesia; in Africa about 1% residue is burned in the fields of the northern drylands, but up to 50% in the humid tropics. We distributed this biomass burning on a spatial grid with resolution of 1° × 1°, and applied emission factors to the amount of dry matter burned to give maps of trace gas emissions in the developing world. The emissions of CO from biofuel use in the developing world, 156 Tg, are about 50% of the estimated global CO emissions from fossil fuel use and industry. The emission of 0.9 Pg C (as CO 2 ) from burning of biofuels and field residues together is small, but nonnegligible when compared with the emissions of CO 2 from fossil fuel use and industry, 5.3 Pg C. The biomass burning source of 10 Tg/yr for CH 4 and 2.2 Tg N/yr of NO x are relatively small when compared with total CH 4 and NO x sources; this source of NO x may be important on a regional basis.
The burning of living and dead biomass, including forests, savanna grasslands and agricultural wastes is much more widespread and extensive than previously believed and may consume as much as 8700 teragrams of dry biomass matter per year. The burning of this much biomass releases about 3940 teragrams of total carbon or about 3550 teragrams of carbon in the form of CO2, which is about 40% of the total global annual production of CO2. Biomass burning may also produce about 32% of the world’s annual production of CO, 24% of the nonmethane hydrocarbons, 20% of the oxides of nitrogen, and biomass burn combustion products may be responsible for producing about 38% of the ozone in the troposphere. Biomass burning has increased with time and today is overwhelmingly human‐initiated.
Biomass‐burning plumes and haze layers were observed during the ABLE 2A flights in July/August 1985 over the central Amazon Basin. The haze layers occurred at altitudes between 1000 and 4000 m and were usually only some 100 to 300‐m thick but extended horizontally over several 100 km. They could be traced by satellite imaging and trajectory studies to biomass burning at the southern perimeter of the Amazon Basin, with transport times estimated to be 1–2 days. These layers strongly influenced the chemical and optical characteristics of the atmosphere over the eastern Amazon Basin. The concentrations of CO, CO 2 , O 3 , and NO were significantly elevated in the plumes and haze layers relative to the regional background. The NO/CO ratio in fresh plumes was much higher than in the aged haze layers, suggesting that more than 80% of the NO x in the haze layers had been converted to nitrate and organic nitrogen species subsequent to emission. The haze aerosol was composed predominantly of organic material, NH 4 + , K + , NO 3 − , SO 4 = , and anionic organic species (formate, acetate, and oxalate). While the concentrations of most aerosol ions were substantially higher in the haze layers than in the regional background aerosol, the ratios between the aerosol ions in the haze layer aerosols were very similar to those in the boundary layer aerosol over the central Amazon region. Simultaneous measurements of trace gas and aerosol species in the haze layers made it possible to derive emission ratios for CO, NO x , NH 3 , sulfur oxides, and aerosol constituents relative to CO 2 . Regional and global emission estimates based on these ratios indicate that biomass burning is an important contributor in the global and regional cycles of carbon, sulfur, and nitrogen species. Similar considerations suggest that photochemical ozone production in the biomass‐burning plumes contributes significantly to the regional ozone budget.
Biomass burning is widespread, especially in the tropics. It serves to clear land for shifting cultivation, to convert forests to agricultural and pastoral lands, and to remove dry vegetation in order to promote agricultural productivity and the growth of higher yield grasses. Furthermore, much agricultural waste and fuel wood is being combusted, particularly in developing countries. Biomass containing 2 to 5 petagrams of carbon is burned annually (1 petagram = 10(15) grams), producing large amounts of trace gases and aerosol particles that play important roles in atmospheric chemistry and climate. Emissions of carbon monoxide and methane by biomass burning affect the oxidation efficiency of the atmosphere by reacting with hydroxyl radicals, and emissions of nitric oxide and hydrocarbons lead to high ozone concentrations in the tropics during the dry season. Large quantities of smoke particles are produced as well, and these can serve as cloud condensation nuclei. These particles may thus substantially influence cloud microphysical and optical properties, an effect that could have repercussions for the radiation budget and the hydrological cycle in the tropics. Widespread burning may also disturb biogeochemical cycles, especially that of nitrogen. About 50 percent of the nitrogen in the biomass fuel can be released as molecular nitrogen. This pyrdenitrification process causes a sizable loss of fixed nitrogen in tropical ecosystems, in the range of 10 to 20 teragrams per year (1 teragram = 10(12) grams).
Burning mouth syndrome (BMS) is characterized by a burning sensation in the oral cavity although the oral mucosa is clinically normal. The syndrome mostly affects middle-aged women. Various local, systemic and psychological factors have been found to be associated with BMS, but its etiology is not fully understood. Oral complaints and salivary flow were surveyed in 669 men and 758 women randomly selected from 48,500 individuals between the ages 20 and 69 years. Fifty-three individuals (3.7%), 11 men (1.6%) and 42 women (5.5%), were classified as having BMS. In men, no BMS was found before the age group 40 to 49 years where the prevalence was 0.7%, which increased to 3.6% in the oldest age group. In women, no BMS was found in the youngest age group, but in the age group 30 to 39 years the prevalence was 0.6% and increased to 12.2% in the oldest age group. Subjective oral dryness, age, medication, taste disturbances, intake of L-thyroxines, illness, stimulated salivary flow rate, depression and anxiety were factors associated with BMS. In individuals with BMS, the most prevalent site with burning sensations was the tongue (67.9%). The intensity of the burning sensation was estimated to be 4.6 on a visual analogue scale. There were no increased levels of depression, anxiety or stress among individuals with more pain compared to those with less pain. It was concluded that BMS should be seen as a marker of illness and/or distress, and the complex etiology of BMS demands specialist treatment.
The Angstrom wavelength exponent α, which is the slope of the logarithm of aerosol optical depth (τ a ) versus the logarithm of wavelength (λ), is commonly used to characterize the wavelength dependence of τ a and to provide some basic information on the aerosol size distribution. This parameter is frequently computed from the spectral measurements of both ground‐based sunphotometers and from satellite and aircraft remote sensing retrievals. However, spectral variation of α is typically not considered in the analysis and comparison of values from different techniques. We analyze the spectral measurements of τ a from 340 to 1020 nm obtained from ground‐based Aerosol Robotic Network radiometers located in various locations where either biomass burning, urban, or desert dust aerosols are prevalent. Aerosol size distribution retrievals obtained from combined solar extinction and sky radiance measurements are also utilized in the analysis. These data show that there is significant curvature in the ln τ a versus ln λ relationship for aerosol size distributions dominated by accumulation mode aerosols (biomass burning and urban). Mie theory calculations of α for biomass burning smoke (for a case of aged smoke at high optical depth) agree well with observations, confirming that large spectral variations in α are due to the dominance of accumulation mode aerosols. A second order polynomial fit to the ln τ a versus ln λ data provides excellent agreement with differences in τ a of the order of the uncertainty in the measurements (∼0.01‐0.02). The significant curvature in ln τ a versus ln λ for high optical depth accumulation mode dominated aerosols results in α values differing by a factor of 3–5 from 340 to 870 nm. We characterize the curvature in ln τ a versus ln λ by the second derivative α′ and suggest that this parameter be utilized in conjunction with α to characterize the spectral dependence of τ a . The second derivative of ln τ a versus ln λ gives an indication of the relative influence of accumulation mode versus coarse mode particles on optical properties.
Abstract. 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 EFs 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. Biomass burning terminology is defined to promote consistency. 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. 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 almost 3 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.
This ethnography explores the emancipatory dynamics of the Burning Man project, a one-week-long antimarket event. Practices used at Burning Man to distance consumers from the market include discourses supporting communality and disparaging market logics, alternative exchange practices, and positioning consumption as self-expressive art. Findings reveal several communal practices that distance consumption from broader rhetorics of efficiency and rationality. Although Burning Man's participants materially support the market, they successfully construct a temporary hypercommunity from which to practice divergent social logics. Escape from the market, if possible at all, must be conceived of as similarly temporary and local. Copyright 2002 by the University of Chicago.
A large body of information on emissions from the various types of biomass burning has been accumulated over the past decade, to a large extent as a result of International Geosphere‐Biosphere Programme/International Global Atmospheric Chemistry research activities. Yet this information has not been readily accessible to the atmospheric chemistry community because it was scattered over a large number of publications and reported in numerous different units and reference systems. We have critically evaluated the presently available data and integrated these into a consistent format. On the basis of this analysis we present a set of emission factors for a large variety of species emitted from biomass fires. Where data were not available, we have proposed estimates based on appropriate extrapolation techniques. We have derived global estimates of pyrogenic emissions for important species emitted by the various types of biomass burning and compared our estimates with results from inverse modeling studies.