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Household fuel use in developing countries, particularly as biomass and coal, is a major source of carbonaceous aerosols and other air pollutants affecting health and climate. Using state-of-the-art emission inventories, a global three-dimensional photochemical tracer/transport model of the troposphere, and a global radiative transfer model based on methods presented in the latest IPCC Assessment Report (2007-AR4), we estimate the radiative forcing (RF) attributable to household fuel combustion in Asia in terms of current global annual-mean RF and future global integrated RF for a one-year pulse of emissions (2000) over two time horizons (100 and 20 years). Despite the significant emissions of black carbon (BC) aerosols, these estimates indicate that shorter-lived (non-Kyoto) air pollutants from household fuel use in the region overall seem to exert a small net negative RF because of the strong influence of reflective aerosols. There are, however, major uncertainties in emission estimates for solid fuel burning, and about the sustainability of household fuel wood harvesting in Asia (the carbon neutrality of harvesting). In addition, there is still substantial uncertainty associated with the BC radiative forcing. As a result we find that the sign of the RF from household biomass burning in the region cannot be established. While recognizing the value of integrating climate change and air pollution policies, we are concerned that for a ‘Kyoto style’ post-Kyoto treaty (with global cap-and-trade and the Global Warming Potential as the metric) expanding the basket of components with a selection of short-lived species without also including the wider range of co-emitted species may lead to unintended consequences for global-scale climate. Additional measurement, modelling, and policy research is urgently needed to reduce the uncertainties so that the net impact on climate of emissions and mitigation measures in this sector can be accurately assessed.

In this study, background concentration sites of Deokjeok and Gosan, which were deemed suitable for monitoring the impact of long-range transported air pollutants, were selected. An investigation of the source types of pollutants, their locations, and relative quantitative contributions to the particulate concentrations at both sites using appropriate methodologies to make initial estimations was conducted. Episodic measurements of PM2.5, PM10, and size distribution, along with its ion and carbon components were performed from 2005 to 2007, and a comprehensive analysis of the results was conducted utilizing back trajectory analysis. As for frequency of wind direction, it was quite apparent that the two sites are heavily influenced by air masses originating from the eastern and northern regions of China. For PM2.5 and PM10, the mass concentrations from north and east China were higher than other cases, originating from the ocean. In the northerly-wind case, meteorological properties for Deokjeok and Gosan and the influence of carbon emissions from northwest Korea resulted in a changing of air mass properties during transport. As was the case with mass concentration, the highest contribution for ionic and carbon components of PM2.5 and PM10 for both sites appeared for the westerly wind case. A specially high relative contribution, greater than 1.4 times, was apparent in the secondary aerosol case because of a large influence of long-range transported pollutants from east China. Carbon components exhibited different behaviors for the northerly and westerly wind cases compared with secondary aerosol. The major reason for this discrepancy appears to be the carbon emissions from northwest Korea.

In this study, NO2 columns from the US EPA Models-3/CMAQ model simulations carried out using the 2001 ACE-ASIA (Asia Pacific Regional Aerosol Characterization Experiment) emission inventory over East Asia were compared with the GOME-derived NO2 columns. There were large discrepancies between the CMAQ-predicted and GOME-derived NO2 columns in the fall and winter seasons. In particular, while the CMAQ-predicted NO2 columns produced larger values than the GOME-derived NO2 columns over South Korea for all four seasons, the CMAQ-predicted NO2 columns produced smaller values than the GOME-derived NO2 columns over North China for all seasons with the exception of summer (summer anomaly). It is believed that there might be some error in the NOx emission estimates as well as uncertainty in the NOx chemical loss rates over North China and South Korea. Regarding the latter, this study further focused on the biogenic VOC (BVOC) emissions that were strongly coupled with NOx chemistry during summer in East Asia. This study also investigated whether the CMAQ-modeled NO2/NOx ratios with the possibly overestimated isoprene emissions were higher than those with reduced isoprene emissions. Although changes in both the NOx chemical loss rates and NO2/NOx ratios from CMAQ-modeling with the different isoprene emissions affected the CMAQ-modeled NO2 levels, the effects were found to be limited, mainly due to the low absolute levels of NO2 in summer. Seasonal variations of the NOx emission fluxes over East Asia were further investigated by a set of sensitivity runs of the CMAQ model. Although the results still exhibited the summer anomaly possibly due to the uncertainties in both NOx-related chemistry in the CMAQ model and the GOME measurements, it is believed that consideration of both the seasonal variations in NOx emissions and the correct BVOC emissions in East Asia are critical. Overall, it is estimated that the NOx emissions are underestimated by ~57.3% in North China and overestimated by ~46.1% in South Korea over an entire year. In order to confirm the uncertainty in NOx emissions, the NOx emissions over South Korea and China were further investigated using the ACE-ASIA, REAS (Regional Emission inventory in ASia), and CAPSS (Clean Air Policy Support System) emission inventories. The comparison between the CMAQ-calculated and GOME-derived NO2 columns indicated that both the ACE-ASIA and REAS inventories have some uncertainty in NOx emissions over North China and South Korea, which can also lead to some errors in modeling the formation of ozone and secondary aerosols in South Korea and North China.

An assessment of how future climate change will impact regional air quality requires projecting emissions many decades into the future in a consistent manner. An approach that integrates the impact of both the current regulations and the longer-term national and global trends is developed to construct an emissions inventory (EI) for North America for the mid-century in support of a regional modeling study of ozone and particulate matter (PM) less than or equal to 2.5 microm (PM2.5). Because the time horizon of such a distant projection is beyond that of EIs used in typical modeling studies, it is necessary to identify a practical approach that allows the emission projections to account for emission controls and climatic and energy-use changes. However, a technical challenge arises because this requires integration of various different types of information with which emissions from human activities are associated. Often, emission information in global models has less detail and uses coarser spatiotemporal resolution. The method developed here is based on data availability, spatiotemporal coverage and resolution, and future-scenario consistency (i.e., Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios [IPCC SRES] A1B), and consists of two major steps: (1) near-future EI projection (to the year 2020), and (2) longer-term EI projection (to mid-century). The first step is based closely on the U.S. Environmental Protection Agency Clean Air Interstate Rule EI, the Environment Canada EI, as well estimates of Mexico's EI; whereas the second step follows approaches proposed by the EI from the Integrated Model to Assess the Global Environment (IMAGE), developed by Netherlands's National Institute for Public Health and the Environment (RIVM). For the United States, the year-2050 emissions for nitrogen oxides (NOx), sulfur dioxide (SO2), PM2.5, anthropogenic volatile organic compounds (VOCs), and ammonia are projected to change by -55, -55, -30, -40, and +20%, respectively, compared with 2001. NOx and SO2 emission changes are very similar in total amount but different in sectoral contribution. The projected emission trends for Canada and Mexico differ considerably. After taking into account the modeled climate changes, biogenic VOC emission increases from three countries overwhelm the decreases in anthropogenic VOC emissions, leading to a net small increase (approximately 2%) in overall VOC emissions.

The purpose of this study is to understand the impact that temperature and relative humidity have on the volatilization loss of particulate nitrate from Teflon filters during measurements of ambient fine particles . Fine particles were measured using an annular denuder system (ADS) at four representive areas in Seoul. The measurements were made during 28 different days at 24-hr sampling intervals from February 14 to October 15, 1997. In this study, nitrate losses. calculated by the ratio of nitrate on the nylon filter to their sum in both Teflon and nylon titters, varied seasonally in the following order: summer (45.5%) > spring (23.8%) > fall (20.6%) > winter (19.7%). The results showed strong correlations with temperature, but we did not observe any significant effects of relative humidity. However, we observed that both temperature and relative humidity influenced the ambient gas/particle nitrate ratio in a different case study using a denuder.

Potential impacts of global climate and emissions changes on regional air quality over southern (western and eastern) Canada and northern Mexico are examined by comparing future summers' (i.e., 2049–2051) average regional O3 and PM2.5 concentrations with historic concentrations (i.e., 2000–2002 summers). Air quality modeling was conducted using CMAQ and meteorology downscaled from the GISS-GCM using MM5. Emissions for North America are found using US EPA, Mexican and Canadian inventories and projected emissions following CAIR and IPCC A1B emissions scenario. Higher temperatures for all sub-regions and regional changes in mixing height, insolation and precipitation are forecast in the 2049-2051 period. Future emissions are calculated to be lower over both Canadian sub-regions, but higher over northern Mexico. Global climate change, alone, is predicted to affect PM2.5 concentrations more than O3 for the projections used in this study: average daily maximum eight (8) hour O3 (M8hO3) concentrations are estimated to be slightly different in all examined sub-regions while average PM2.5 concentrations are estimated to be higher over both Canadian sub-regions (8% over western and 3% over eastern) but 11% lower over northern Mexico. More days are forecast where M8hO3 concentrations are over 75 ppb in all examined sub-regions but the number of days where PM2.5 concentration will be over 15 μg/m3 is projected higher only over western Canada. Climate change combined with the projected emissions lead to greater change in pollutant concentrations: average M8hO3 concentrations are simulated to be 6% lower over western Canada and 8% lower over eastern Canada while average PM2.5 concentrations are simulated to be 5% lower over western Canada and 11% lower over eastern Canada. Although future emissions over northern Mexico are projected higher, pollutant concentrations are simulated to be lower due to US emissions reductions. Global climate change combined with the projected emissions will decrease average M8hO3 4% and PM2.5 17% over northern Mexico. Significant reductions in the number of days where M8hO3 concentrations are over 75 ppb and PM2.5 concentration over 15 μg/m3 are also projected with a significant reduction in peak values.

A numerical simulation study to quantify the effect of upstream transport and fossil-fuel and biomass-burning emissions from East Asia on the surface ozone near Taiwan has been performed based on data taken April 8-13, 2001, when a cold air outbreak occurred. The TAQM (Taiwan Air Quality Model) is employed in this study. Results show that, without considering emissions in East Asia, upstream transport of chemical species associated with the movement of the cold air mass increased the levels of CO and ozone near Taiwan from 75 to 180ppbv, and 35 to 55ppbv, respectively. Fossil-fuel and biomass-burning emissions can thus result in a significant increase of CO and ozone levels (70-150% and 50-100%, respectively) from the emissionless background. The most noteworthy phenomenon is that biomass burning in Eastern China alone can contribute up to 20% of the increase for these species, while the biomass burning in Southeast Asia has negligible influence.

The fate and transport of mercury in East Asia is evaluated using the Sulfur Transport and dEposition Model (STEM)-Hg 3-D model. The model calculates mercury transport, transformation and deposition in East Asia during April 2001, the period of the ACE-Asia field campaign. Model predictions of dry and wet deposition are compared with the observations from 10 sampling sites in Japan. The model results are consistent with the observations, but tend to over-predict dry deposition. Sensitivity analysis of predicted results to uncertainties in the mercury reaction rates suggests that the oxidation of Hg0 to Hg(II) in the gas phase is the dominant pathway for atmospheric mercury removal processes. Simulation based on the most recently published reaction rate constants for gas phase oxidation of Hg0 to Hg(II) overestimates the production of Hg(II) in the gas phase. The regional mercury budget is calculated which shows that most of the reactive gas phase mercury (RGM) and particulate mercury (Hgp) are deposited around the source region while 28.5 Mg of Hg0 is exported out of East Asia during April 2001. The sensitivity analysis in the regional Hg budget to major uncertainties associated with Hg emission estimates and Hg chemistry are also evaluated.

An inverse modeling method using the four-dimensional variational data assimilation approach is developed to provide a top-down estimate of mercury emission inventory in China. The mercury observations on board the C130 aircraft during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) campaign in April 2001 are assimilated into a regional chemical transport model, STEM. Using a 340 Mg of elemental mercury emitted in 1999, the assimilation results in an increase in Hg 0 emissions for China to 1140 Mg in 2001. This is an upper limit amount of the elemental mercury required in China. The average emission-scaling factor is ∼3.4 in China. The spatial changes in the mercury emissions after the assimilation are also evaluated. The largest changes are estimated on the China north-east coastal areas and the areas of north-center China. The influences of the observation and inventory uncertainties and the initial and boundary conditions on the emission estimates are discussed. Increasing the boundary conditions of Hg from 1.2 to 1.5 ng m −3 , results in a top-down estimate of Hg 0 emissions for China of 718 Mg, and leads the average scaling factor from 3.4 to 2.1.

In this study, the accuracy of NH3 emissions in East Asia is evaluated by a comparison of measured and predicted NH4NO3 concentrations. For the prediction of particulate NH4NO3 concentrations, this study uses the USEPA Models-3/Community Multi-scale Air Quality (Models-3/CMAQ) model. The measurement data are collected from 4 ground-based stations (Beijing, Shanghai, Qingdao, and Kangwha) and ACE-ASIA C130 Flights #6, #7, and #10. The four ground-based stations and air flight tracks are located in and around the Yellow Sea in East Asia. According to the results, the predicted fine-mode NH4+concentrations are 1.2–3.8 times overestimated compared to those measured on the mass basis, and fine-mode NO3− concentrations are 1.9–7.6 times overestimated on the mass basis. It is also revealed in this study that aberrantly high predicted fine-mode NO3− concentrations in East Asia can be attributed to the overestimated NH3 emissions. The predicted gas-phase NH3 concentrations and estimated NH3 emissions are likely to be 1.2–3.8 times overestimated in East Asia on the mass basis. Therefore, it is recommended that approximately 20–75% reduced NH3 emission fields should be used in future modeling studies for East Asia.

Long-range transport of pollutants influenced by anthropogenic and natural emission sources in East Asia is investigated by using backward trajectory analysis along the NASA TRACE-P flight tracks and a numerical simulation with the three-dimensional chemical transport model (STEM-2k1). Observation-based regional distributions of trace gases are reconstructed using the observations obtained by measurements on board the DC-8 and P3-B aircrafts. Systematic features of the spatial distribution for each species are identified. It is found that the observed concentrations of CO and some NMHCs, and the ratios between these species, are highly associated with the source distribution features and their regional characteristics. Reconstructed fields of the observed and modeled ethane/CO and ethane/propane are found to reproduce well the estimated emission ratios in East Asia. We also investigated the time rate of change of the concentration of species and their ratio along the trajectory. From this analysis the propane/ethane and propane/acetylene ratios are shown to preserve their emission ratios during regional transport. However systematic differences in the propane vs. acetylene/CO relationships are found between the model and observation values. This analysis suggests that further efforts are needed to improve the estimates of biomass burning emissions in SE Asia. The results presented in this paper also suggest ways to further extend the capabilities to derive observation-based inventories.

The relationship between SO 2 emissions and the effective particle radius of low-level water clouds ( r e ) over China was investigated to determine anthropogenic effects on clouds. Sulfur dioxide emission values were obtained from a statistical inventory, and r e origins were retrieved by satellite remote sensing on a 0.5° grid. Comparisons between annual mean SO 2 emissions and r e showed generally decreasing r e values, explained by the Twomey effect. The existence of the Twomey effect is supported by comparisons with simulated aerosol optical depths. Results further suggest that clouds over land show sensitivity to the Twomey effect as well as clouds over the ocean.

Asia is undergoing rapid urbanization resulting in increasing air pollution threats in its cities. The contribution of megacities to sulfur emissions and pollution in Asia is studied over a 25-year period (1975–2000) using a multi-layer Lagrangian puff transport model. Asian megacities cover 10% in 2000. Two future emission scenarios are evaluated for 2020—“business as usual (BAU)” and “maximum feasible controls (MAXF)” to establish the range of reductions possible for these cities. The MAXF scenario would result in 2020 S-emissions that are ∼80% lower than those in 2000, at an estimated control cost of US $87 billion per year (1995 US$) for all of Asia. An urban scale analysis of sulfur pollution for four megacities—Shanghai, and Chongqing in China; Seoul in South Korea; and Mumbai (formerly Bombay) in India is presented. If pollution levels were allowed to increase under BAU, over 30 million people in these cities alone would be exposed to levels in excess of the WHO guidelines.

Emissions in East Asia for 1993 by administrative units and source types are estimated to support regional emission assessments and transport modeling studies. Total emission of SOx, NOx, soil NOx, N2O, and NH3 are 24 150, 12 610, 1963, 908, and 8263 kton yr-1, respectively.China's emission contribution is the highest for every species.The area sources are the most significant source type for SOx and NOx, but the fraction due to mobile source is highest for NOx. Major LPSs are located from the middle to the east part of China, south and middle-west part of South Korea, and the east part of Japan. The area sources of SOx show a pattern similar to population density, whereas NH3 shows a strong landuse dependency. Detail emissions analysis reveals higher SOx emission `cores' within each province. The estimated emissions are used to estimate sulfur deposition in the regions. The seasonal average sulfur distribution amounts are estimated from the ATMOS2 chemical transport model. The results showed anti-correlation with temperature for sulfur (SO2 + SO4-2) concentrations and a positive correlation with rainfall for deposition.

An intercomparison study involving eight long-range transport models for sulfur deposition in East Asia has been initiated. The participating models included Eulerian and Lagrangian frameworks, with a wide variety of vertical resolutions and numerical approaches. Results from this study, in which models used common data sets for emissions, meteorology, and dry, wet and chemical conversion rates, are reported and discussed. Model results for sulfur dioxide and sulfate concentrations, wet deposition amounts, for the period January and May 1993, are compared with observed quantities at 18 surface sites in East Asia. At many sites the ensemble of models is found to have high skill in predicting observed quantities. At other sites all models show poor predictive capabilities. Source–receptor relationships estimated by the models are also compared. The models show a high degree of consistency in identifying the main source–receptor relationships, as well as in the relative contributions of wet/dry pathways for removal. But at some locations estimated deposition amounts can vary by a factor or 5. The influence of model structure and parameters on model performance is discussed. The main factors determining the deposition fields are the emissions and underlying meteorological fields. Model structure in terms of vertical resolution is found to be more important than the parameterizations used for chemical conversion and removal, as these processes are highly coupled and often work in compensating directions.

Emissions of air pollutants in East Asia play an important role in the regional and global atmospheric environment. In this study we evaluated the recent emission trends of sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), and non-methane volatile organic compounds (NMVOC) in East Asia, and projected their future emissions up until 2030 with six emission scenarios. The results will provide future emission projections for the modeling community of the model inter-comparison program for Asia (MICS-Asia). During 2005–2010, the emissions of SO2 and PM2.5 in East Asia decreased by 15 and 12%, respectively, mainly attributable to the large-scale deployment of flue gas desulfurization (FGD) at China's power plants, and the promotion of highly efficient PM removal technologies in China's power plants and cement industry. During this period, the emissions of NOx and NMVOC increased by 25 and 15%, driven by rapid increase in the emissions from China due to inadequate control strategies. In contrast, the NOx and NMVOC emissions in East Asia except China decreased by 13–17%, mainly due to the implementation of stringent vehicle emission standards in Japan and South Korea. Under current regulations and current levels of implementation, NOx, SO2, and NMVOC emissions in East Asia are projected to increase by about one-quarter over 2010 levels by 2030, while PM2.5 emissions are expected to decrease by 7%. Assuming enforcement of new energy-saving policies, emissions of NOx, SO2, PM2.5 and NMVOC in East Asia are expected to decrease by 28, 36, 28, and 15%, respectively, compared with the baseline case. The implementation of "progressive" end-of-pipe control measures would lead to another one-third reduction of the baseline emissions of NOx, and about one-quarter reduction of SO2, PM2.5, and NMVOC. Assuming the full application of technically feasible energy-saving policies and end-of-pipe control technologies, the emissions of NOx, SO2, and PM2.5 in East Asia would account for only about one-quarter, and NMVOC for one-third, of the levels of the baseline projection. Compared with previous projections, this study projects larger reductions in NOx and SO2 emissions by considering aggressive governmental plans and standards scheduled to be implemented in the next decade, and quantifies the significant effects of detailed progressive control measures on NMVOC emissions up until 2030.

Monitoring air quality for daily life gets more and more attention Especially in modern urban environment with high skylines and unexpected pollution events, it is important to have micro-scale monitoring in addition to traditional monitoring methods We propose a micro-scale modeling system as well as a micro-scale air quality monitoring system, which comprises as a micro-scale air quality management system, named AirScope AirScope consists of CFD-based air quality modeling, USN-based sensor monitoring, and multi-modal interaction platform In this paper, we present a brief overview of AirScope and several aspects of constructed initial indoor test environment with a few validity tests The proposed system will be extended to an outdoor real-world testbed with most of modern urban elements.

This paper provides a synthesis of results that have emerged from recent modeling studies of the potential sensitivity of U.S. regional ozone (O3) concentrations to global climate change (ca. 2050). This research has been carried out under the auspices of an ongoing U.S. Environmental Protection Agency (EPA) assessment effort to increase scientific understanding of the multiple complex interactions among climate, emissions, atmospheric chemistry, and air quality. The ultimate goal is to enhance the ability of air quality managers to consider global change in their decisions through improved characterization of the potential effects of global change on air quality, including O3 The results discussed here are interim, representing the first phase of the EPA assessment. The aim in this first phase was to consider the effects of climate change alone on air quality, without accompanying changes in anthropogenic emissions of precursor pollutants. Across all of the modeling experiments carried out by the different groups, simulated global climate change causes increases of a few to several parts per billion (ppb) in summertime mean maximum daily 8-h average O3 concentrations over substantial regions of the country. The different modeling experiments in general do not, however, simulate the same regional patterns of change. These differences seem to result largely from variations in the simulated patterns of changes in key meteorological drivers, such as temperature and surface insolation. How isoprene nitrate chemistry is represented in the different modeling systems is an additional critical factor in the simulated O3 response to climate change.

Nowadays, air quality problems are getting more serious. Without having a good outdoor air quality, indoor air quality also could be a serious problem. The Seoul Metro of Korea always wants to reduce air pollution in the subway stations for people using subway as daily transportation. Fine particles (such as, PM10, PM2.5) are well known pollutants that can cause many diseases. In this paper we discuss framework design of the Integrated Air Quality Management System for Subway (IUMS) in support of subway stations' air quality improvement. By using this system the Metro subway office clerks can automatically monitoring and controlling the status of air quality in a subway station. To make this IT-based air quality system more efficient and realistic, PM10 mass and ion had been measured at the four subway stations in Seoul. The measurements were conducted in four different compartments in a station so that we can find sources and processes of particle pollution. From these joint effort of IT-ET, we are expecting to get cleaner-but-greener air quality management system.

In recent years, the environmental problems have become considerably big issues throughout the world. For knowing the environmental problems we have to measure the environment quality and get the data by monitoring the environment. Currently there are many researches are going on in this area. Those researches are using big and expensive environmental measurement equipment. In this reason, they cannot install enough equipment to measure micro-scale area. This lead us to work on a micro-scale air quality monitoring system named AirScope. In AirScope we are using small and cheep sensors for monitoring the urban air quality. In this paper we present AirScope testbed to reduce the problems when we deploy to the micro scale.

Today, the environmental observing systems are no longer strange to the people, and they are playing an important role in e-sciences, especially in researches about earthquake, climate, air pollution, etc. To be named as Airscope [1], this micro-scale air quality management system deals with unexpected pollution events in small scope, by using CFD-based air quality modeling [2], USN-based sensor monitoring model, DataTurbine middleware [3], multi-model interaction platforms and devices. Because of these complicated heterogeneity tools and devices, data transferring inside this project is very important and is a backbone for the whole system. In this paper, we will briefly introduce Airscope project and its elements, our indoor testbed and especially the data flows inside. We also describe about an extended actual system to apply in reality such as a small area in modern urban.

Uncertainties in calculated impacts of climate forecasts on future regional air quality are investigated using downscaled MM5 meteorological fields from the NASA GISS and MIT IGSM global models and the CMAQ model in 2050 in the continental US. Differences between three future scenarios: high-extreme, low-extreme and base case, are used for quantifying effects of climate uncertainty on regional air quality. GISS, with the IPCC A1B scenario, is used for the base case simulations. IGSM results, in the form of probabilistic distributions, are used to perturb the base case climate to provide the high- and low-extreme scenarios. Impacts of the extreme climate scenarios on concentrations of summertime fourth-highest daily maximum 8-h average ozone are predicted to be up to 10 ppbV (about one-seventh of the current US ozone standard of 75 ppbV) in urban areas of the Northeast, Midwest and Texas due to impacts of meteorological changes, especially temperature and humidity, on the photochemistry of tropospheric ozone formation and increases in biogenic VOC emissions, though the differences in average peak ozone concentrations are about 1–2 ppbV on a regional basis. Differences between the extreme and base scenarios in annualized PM2.5 levels are very location dependent and predicted to range between −1.0 and +1.5 μg m−3. Future annualized PM2.5 is less sensitive to the extreme climate scenarios than summertime peak ozone since precipitation scavenging is only slightly affected by the extreme climate scenarios examined. Relative abundances of biogenic VOC and anthropogenic NOx lead to the areas that are most responsive to climate change. Overall, planned controls for decreasing regional ozone and PM2.5 levels will continue to be effective in the future under the extreme climate scenarios. However, the impact of climate uncertainties may be substantial in some urban areas and should be included in assessing future regional air quality and emission control requirements., United States. Environmental Protection Agency (Science To Achieve Results (STAR) grant No. RD83096001), United States. Environmental Protection Agency (Science To Achieve Results (STAR) grant No. RD82897602), United States. Environmental Protection Agency (Science To Achieve Results (STAR) grant No. RD83107601), East Tennessee State University

In this paper, we present a framework for micro-scale air quality monitoring and sensor management system. The developed system is validated in a preliminary test environment. The test result shows that it is feasible to adopt sensor networks for micro-scale monitoring. In the future, enhancements on the VR core modules will also be investigated such as enhanced interaction devices, mobile sensors, and display devices. Finally, we will also build web-based information portal to be used by citizens whenever the information is needed.

These days the environmental problem became the most sensitive issue through the whole world. There were lots of studies in progress for monitoring and managing the environmental data. However, it usually required expensive and huge equipment, therefore, have serious restriction on this kind of research. To solve the problem we propose a solution with sensors - micro-scale environmental monitoring system. In now day the environment monitoring have not much data to share but if the micro-scale monitoring starts it could not share much data with centralized system. If we change to distribute system it could share lots of data in one way. With this monitoring system we can monitor and manage data in real-time from sensors which were spread over the target area.

Responses of ozone and PM2.5 to emission changes are coupled because of interactions between their precursors. Here we show the interdependencies of ozone and PM2.5 responses to emission changes in 2001 and 2050, with the future case accounting for both currently planned emission controls and climate change. Current responses of ozone and PM2.5 to emissions are quantified and linked on a daily basis for five cities in the continental United States: Atlanta, Chicago, Houston, Los Angeles, and NewYork. Reductions in anthropogenic NO(x) emissions decrease 24-h average PM2.5 levels but may either increase or decrease daily maximum 8-h average ozone levels. Regional ozone maxima for all the cities are more sensitive to NO(x) reductions than at the city center, particularly in New York and Chicago. Planned controls of anthropogenic NO(x) emissions lead to more positive responses to NO(x) reductions in the future. Sensitivities of ozone and PM2.5 to anthropogenic VOC emissions are predicted to decrease between 2001 and 2050. Ammonium nitrate formation is predicted to be less ammonia-sensitive in 2050 than 2001 while the opposite is true for ammonium sulfate. Sensitivity of PM2.5 to SO2 and NO(x) emissions changes little between 2001 and 2050. Both ammonium sulfate and ammonium nitrate are predicted to decrease in sensitivity to SO2 and NO(x) emissions between 2001 and 2050. The complexities, linkages, and daily changes in the pollutant responses to emission changes suggest that strategies developed to meet specific air quality standards should consider other air quality impacts as well.

[1] Potential impacts of global climate change and emissions on the total nitrogen and sulfur deposition over the US are investigated. Three future years' annual average deposition rates (i.e., 2049–2051) are compared with historic ones (i.e., 2000–2002) accounting for existing US and individual State's emission regulations and strategies. Impacts of global climate change alone on regional nitrogen and sulfur deposition are small compared to impacts from emission control-related reductions for the projections used in this study. The combined effect of climate change and emission reductions is a decrease in the annual average nitrogen and sulfur deposition over the US. Reduced nitrogen species dominate oxidized nitrogen deposition in the future. Spatial distribution plots for both components show lower deposition rates in the future mainly in the middle and eastern States where reductions in NOx and SO2 emissions are more pronounced.

[1] High resolution in situ measurements of atmospheric CO2 were made from the NASA DC-8 aircraft during the Intercontinental Chemical Transport Experiment–North America (INTEX-NA) campaign, part of the wider International Consortium for Atmospheric Research on Transport and Transformation (ICARTT). During the summer of 2004, eighteen flights comprising 160 h of measurements were conducted within a region bounded by 27 to 53°N and 36 to 139°W over an altitude range of 0.15 to 12 km. These large-scale surveys provided the opportunity to examine the characteristics of the atmospheric CO2 signal over sparsely sampled areas of North America and adjacent ocean basins. The observations showed a high degree of variability (≤18%) due to the myriad source and sink processes influencing the air masses intercepted over the INTEX-NA sampling domain. Surface fluxes had strong effects on continental scale concentration gradients. Clear signatures of CO2 uptake were seen east of the Mississippi River, notably a persistent CO2 deficit in the lowest 2–3 km. When combining the airborne CO2 measurements with LANDSAT and MODIS data products, the lowest CO2 mixing ratios observed during the campaign (337 ppm) were tied to mid-continental agricultural fields planted in corn and soybeans. We used simultaneous measurements of CO, O3, C2Cl4, C2H6, C2H2 and other unique chemical tracers to differentiate air mass types. Coupling these distinct air mass chemical signatures with transport history permitted identification of convection, stratosphere-troposphere exchange, long-range transport from Eastern Asia, boreal wildfires, and continental outflow as competing processes at multiple scales influencing the observed concentrations. Our results suggest these are important factors contributing to the large-scale distribution in CO2 mixing ratios thus these observations offer new constraints in the computation of the North American carbon budget.

Simulated future summers (i.e., 2049-2051) and annual (i.e., 2050) average regional O 3 and PM2.5 concentrations over North America are compared with historic (i.e., 2000-2002 summers and all of 2001) levels to investigate the potential impacts of global climate change on regional air quality. Meteorological inputs to the CMAQ chemical transport model are developed by downscaling the GISS Global Climate Model simulations using an MM5-based regional climate model. Future-year emissions for North America are developed by growing the US EPA CAIR inventory, Mexican and Canadian emissions and by using the IMAGE model with the IPCC A1B emissions scenario that is also used in projecting future climate. Reductions of more than 50% in NOX and SO2 emissions are forecast. The impacts of global climate change alone on regional air quality are small compared to impacts from emission control-related reductions in the US and Canada. The combined effect of climate change and emission reductions lead to a 20% decrease (regionally varying from -11% to -28% regionally) in the mean summer maximum daily 8-hr ozone levels (M8hO3) over the US, -8% over Canada and -10% over Northern Mexico. The mean annual PM2.5 concentrations are estimated to be 23% lower (varies from -9% tomore » -32%) over the US, -7% and -15% over Western and Eastern Canada, respectively and -25% over Northern Mexico. Major reductions are expected in sulfate, nitrate and ammonium fractions of annually-averaged PM2.5 for all sub-regions. The limited reduction in organic carbon over the US and Northern Mexico and the higher concentrations over Canada suggests that organic carbon will be the dominant component of PM2.5 mass over most of the continent in the future. Regionally, the Eastern US benefits more than the rest of the regions from reductions in both M8hO3 and PM2.5, due to both spatial variations in the meteorological and emissions changes. Reduction in the higher M8hO3 concentrations is also estimated for all sub-regions and less days with M8hO3 above the air quality standards in urban sites with Atlanta in the Southeast benefiting most.« less

[1] The regional radiative impact of biomass-burning aerosols in Asia is estimated using the new and detailed emission data during the experimental period of Transport and Chemical Evolution over the Pacific (TRACE-P) in March 2001. Integration of the USA National Oceanic and Atmospheric Administration (NOAA) Hybrid Single-Particle Lagrangian Integrated Transport model (HYSPLIT) and a solar radiative transfer model (CLIRAD-SW) allow us to simulate the spatial and temporal distributions of black carbon (BC) and organic carbon (OC) aerosols from biomass burning in the South Asian region. It also allows us to estimate further their aerosol optical properties and radiative forcing. We find that an anticyclone over Bay of Bengal dominates the transport of pollutants of the South Asian region. The monthly mean surface concentration of OC and BC is 1.1 μg m−3 in this region. Western Myanmar has the maximum value, with the concentration reaching 12.5 μg m−3. The monthly mean clear-sky direct shortwave radiative forcing ranges from −1.9 to 0.4 W m−2 at the top of the atmosphere and from −0.5 to −12.0 W m−2 at surface, resulting in an increase of the atmospheric heating rate from 0.01 to 0.3°C day−1. Owing to the spatial distributions of the aerosol optical depth ratio (OC/BC) and the surface albedo, there is a strong gradient of heating rate near the source regions, which may modify local circulations.

[1] Mercury tracer model simulations are performed to support the analysis of the total gas phase mercury (TGM) observations on 15 flights of the NSF/NCAR C-130 aircraft during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) campaign conducted during April 2001. Ninety-seven percent of the observed mercury concentrations are greater than 1.2 ng/m3. The mean value of the observations is 1.9 ng/m3. No simple relationships between Hg-CO and Hg-total sulfur are found; however, strong correlations are observed in individual flight segments. Backward trajectory analysis is used to help characterize regional of Hg/CO ratios, and these are compared with emission-based ratios from the various sectors. Model predictions using new Hg emission estimates are presented and compared to the observations. Under the condition of a mercury background level of 1.2 ng/m3 the tracer model underestimates the observations when the flights were over the Yellow Sea but is consistent with the observations when the flights were over the Japan Sea. Further analysis suggests that Hg emissions are underestimated in north central China and the eastern coastal areas of China. Model sensitivity studies indicate that the emissions of China may be underestimated by 80–200%.

New emission inventories were developed in support of the Aerosol Characterization Experiments(ACE)-Asia and Transport and Chemical Evolution over the Pacific (TRACE-P) experiments work on. We combine our inventories into the ACCESS(AceAsia and Trace-P Modeling and Emission Support System) for more integrated support for these two field studies. To support field experiments and complex atmospheric models such as STEM-II, highly resolved level of spatial, temporal, and speciescomponent detail are needed in emission inventories. To satisfy these requirements we include not only the gaseous pollutants CO, and NMVOC, but particulate pollutants such as Black Carbon, Organic Carbon, and for the study domain of Asia. Our domain was designed to cover – 13°~53° in latitude and 60°~157° in longitude. It includes 22 Asian countries, 60 subregions. 115 active LPSs and 22 volcanos are also included as point sources. The data system includes information on various emission sources, compiled by fuels and by economic sector activities, and natural emission sources such as volcano and forest fires. So, the methodologies for estimating emission are different between anthropogenic and biomass burning from fires. For anthropogenic emission, we use year 2000 emission database from Argonne National Laboratory. The data themselves are administrative–level estimates recently compiled from official national statistics and projections. For spatial allocation of regional emission, we use geographical data from The International Institute for Applied Systems Analysis (IIASA), Global Emissions Inventory Activity (GEIA), Central

We develop a source-specific high-resolution emission inventory for the Shandong region of eastern China for 2000 and 2020. Our emission estimates for year 2000 are higher than other studies for most pollutants, due to our inclusion of rural coal consumption, which is significant but often underestimated. Still, our inventory evaluation suggests that we likely underestimate actual emissions. We project that emissions will increase greatly from 2000 to 2020 if no additional emission controls are implemented. As a result, PM2.5 concentrations will increase; however O3 concentrations will decrease in most areas due to increased NOx emissions and VOC-limited O3 chemistry. Taking Zaozhuang Municipality in this region as a case study, we examine possible changes in emissions in 2020 given projected growth in energy consumption with no additional controls utilized (BAU), with adoption of best available end-of-pipe controls (BACT), and with advanced, low-emission coal gasification technologies (ACGT) which are capable of gasifying the high-sulfur coal that is abundant in China. Emissions of NH3 are projected to be 20% higher, NMVOC50% higher, and all other species 130–250% higher in 2020 BAU than in 2000. Both alternative 2020 emission scenarios would reduce emissions relative to BAU. Adoption of ACGT, which meets only 24% of energy service demand in Zaozhuang in 2020 would reduce emissions more than BACT with 100% penetration. In addition, coal gasification technologies create an opportunity to reduce greenhouse gas emissions by capturing and sequestering CO2 emissions below ground. r 2005 Elsevier Ltd. All rights reserved. Keyword: Air pollution; Particulate matter; CO2; Energy technology; Coal

International audience; One of the main uncertainties in the estimation of the climatic impact of aerosols is linked to our knowledge of gas and aerosol emissions. This is particularly crucial over Asia, where a strong regional fingerprint is observed, with different emission types, depending on the various vegetation and climate conditions (biomass burning emissions) and on the very fast changes of the population and industrialization (biofuel and fossil fuel emissions). The main contribution of this work is to derive a biomass burning inventory of 1° × 1° over Asia (the Asian biomass burning inventory (ABBI)) for gases and particles for the Aerosol Characterization Experiment-Asia (ACE-Asia) and Transport and Chemical Evolution Over the Pacific (TRACE-P) campaign period (March to May 2001) in 2001. In this paper we apply new estimates of burnt biomass area to estimate emissions. The method is based on burnt areas (GBA2000 project; Tansey et al. (2002) and Grégoire et al. (2003)) obtained from 1 km resolution SPOT-VEGETATION satellite data. Regional-scale maps of burnt areas are produced, and then spatial and temporal emission distribution are obtained from biomass density and emission factors. Strength and weaknesses associated with the use of satellite products are discussed, including the problem of subpixel classification and the lack of validation data for the accuracy assessment of the products for the studied area. Estimated emissions are compared with ACE-Asia and TRACE-P Modeling and Emission Support System (ACESS) climatological estimates. In addition, interannual variability is estimated by preparing inventories for the years 2000 and 2001

[1] Measurements from the Transport and Chemical Evolution over the Pacific (TRACE-P) and Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) field experiments obtained during the period of March–April 2001 are used to evaluate the impact of megacity emissions on regional air quality in east Asia. A classification method built upon back trajectory analysis and sensitivity runs using the Sulfur Transport and Emissions Model 2001 (STEM-2K1) regional chemical transport model are used to identify the aircraft observations that were influenced by megacity emissions. More than 30% of measurement points are classified as urban points, with a significant number of plumes found to have originated from Shanghai, Qingdao, Beijing, Taiyuan, Tianjin and Guiyang, Seoul, and Pusan. These data are then analyzed, and chemical characteristics of these megacities are compared. Emission estimates for the megacities are also presented and discussed in the context of expected similarities and differences in the chemical signals in the ambient air impacted by these cities. Comparisons of the observation-based ratios with emission-based estimates are presented and provide a means to test for the consistency of the emission estimates. The observation-based ratios are shown to be generally consistent with the emissions ratios. The megacity emissions are used in the STEM-2K1 model to study the effects of these emissions on criteria and photochemical species in the region. Over large portions of the Japan Sea, Yellow Sea, western Pacific Ocean, and the Bay of Bengal, megacity emissions contribute in excess of 10% of the near-surface ambient levels of O3, CO, SO2, H2SO4, HCHO, and NOz. The megacity emissions are also used to study ozone levels in Asia under a scenario where all cities evolve their emissions in a manner such that they end up with the same VOC/NOx emission ratio as that for Tokyo. Monthly mean ozone levels are found to increase by at least 5%.

[1] We evaluate the TRACE-P emission inventories for gaseous and particulate pollutants from East Asia using chemical measurements made at a rural site in China during the China-MAP Field Intensive in conjunction with a coupled regional climate/chemical transport modeling system. Time-dependent, three-dimensional fields for trace gas and particulate matter concentrations over East Asia are simulated by an updated version of the Regional Acid Deposition Model (RADM) driven by the TRACE-P emission inventories along with meteorology fields calculated by the NCAR Regional Climate Model (RegCM) for the month of November 1999. Model-calculated SO2 is in good agreement with measurements, while CO and particulate carbon (PC) are significantly smaller, and particulate sulfate (SO4� ) is somewhat smaller. Our calculations suggest that increases in the TRACE-P emission inventory of CO by � 50% and PC by 60–90% would bring the model-calculated CO, PC, and particulate sulfate concentration into agreement with the China-MAP observations. If these increases were spread uniformly throughout China and the year, it would require that there be additional emissions in China of CO and PC of 60 Tg yr � 1 and 2.5–4 Tg yr � 1 , respectively. Further analysis of high resolution gas species measurements suggests that the missing CO emissions are likely to be associated with SO2 emissions from coal burning. This in turn suggests that coal-burning facilities in China are operating at significantly lower efficiencies than currently assumed. INDEX TERMS: 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; 0368 Atmospheric Composition and Structure: Troposphere—constituent transport and chemistry; KEYWORDS: anthropogenic emissions, East Asia, regional modeling

[ 1] Regional modeling analysis for the Intercontinental Transport and Chemical Transformation 2002 (ITCT 2K2) experiment over the eastern Pacific and U. S. West Coast is performed using a multiscale modeling system, including the regional tracer model Chemical Weather Forecasting System (CFORS), the Sulfur Transport and Emissions Model 2003 (STEM-2K3) regional chemical transport model, and an off-line coupling with the Model of Ozone and Related Chemical Tracers ( MOZART) global chemical transport model. CO regional tracers calculated online in the CFORS model are used to identify aircraft measurement periods with Asian influences. Asian-influenced air masses measured by the National Oceanic and Atmospheric Administration (NOAA) WP-3 aircraft in this experiment are found to have lower DeltaAcetone/DeltaCO, DeltaMethanol/DeltaCO, and DeltaPropane/DeltaEthyne ratios than air masses influenced by U. S. emissions, reflecting differences in regional emission signals. The Asian air masses in the eastern Pacific are found to usually be well aged (> 5 days), to be highly diffused, and to have low NOy levels. Chemical budget analysis is performed for two flights, and the O-3 net chemical budgets are found to be negative ( net destructive) in the places dominated by Asian influences or clear sites and positive in polluted American air masses. During the trans-Pacific transport, part of gaseous HNO3 was converted to nitrate particle, and this conversion was attributed to NOy decline. Without the aerosol consideration, the model tends to overestimate HNO3 background concentration along the coast region. At the measurement site of Trinidad Head, northern California, high-concentration pollutants are usually associated with calm wind scenarios, implying that the accumulation of local pollutants leads to the high concentration. Seasonal variations are also discussed from April to May for this site. A high-resolution nesting simulation with 12-km horizontal resolution is used to study the WP-3 flight over Los Angeles and surrounding areas. This nested simulation significantly improved the predictions for emitted and secondary generated species. The difference of photochemical behavior between the coarse (60-km) and nesting simulations is discussed and compared with the observation.

Although continental-scale plumes of Asian dust and pollution reduce the amount of solar radiation reaching the earth's surface and perturb the chemistry of the atmosphere, our ability to quantify these effects has been limited by a lack of critical observations, particularly of layers above the surface. Comprehensive surface, airborne, shipboard, and satellite measurements of Asian aerosol chemical composition, size, optical properties, and radiative impacts were performed during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) study. Measurements within a massive Chinese dust storm at numerous widely spaced sampling locations revealed the highly complex structure of the atmosphere, in which layers of dust, urban pollution, and biomass-burning smoke may be transported long distances as distinct entities or mixed together. The data allow a first-time assessment of the regional climatic and atmospheric chemical effects of a continental-scale mixture of dust and pollution. Our results show that radiative flux reductions during such episodes are sufficient to cause regional climate change.

In this paper, aerosol composition and size distributions in east Asia are simulated using a comprehensive chemical transport model. Three-dimensional aerosol simulations for the TRACE-P and ACE-Asia periods are performed and used to help interpret actual observations. The regional chemical transport model, STEM-2K3, which includes the on-line gas-aerosol thermodynamic module SCAPE II, and explicitly considers chemical aging of dust, is used in the analysis. The model is found to represent many of the important observed features. The Asian outflow during March and April of 2001 is heavily polluted with high aerosol loadings. Under conditions of low dust loading, SO_2 condensation and gas phase ammonia distribution determine the nitrate size and gas-aerosol distributions along air mass trajectories, a situation that is analyzed in detail for two TRACE-P flights. Dust is predicted to alter the partitioning of the semivolatile components between the gas and aerosol phases as well as the size distributions of the secondary aerosol constituents. Calcium in the dust affects the gas-aerosol equilibrium by shifting the equilibrium balance to an anion-limited status, which benefits the uptake of sulfate and nitrate, but reduces the amount of aerosol ammonium. Surface reactions on dust provide an additional mechanism to produce aerosol nitrate and sulfate. The size distribution of dust is shown to be a critical factor in determining the size distribution of secondary aerosols. As much of the dust mass is found in the supermicron mode (70–90%), appreciable amounts of sulfate and nitrate are found in the supermicron particles. For sulfate the observations and the analysis indicate that 10–30% of sulfate is in the supermicron fraction during dust events; in the case of nitrate, more than 80% is found in the supermicron fraction.

[1] An extensive set of carbonyl sulfide (OCS) and carbon disulfide (CS2) observations were made as part of the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) project, which took place in the early spring 2001. TRACE-P sampling focused on the western Pacific region but in total included the geographic region 110°E to 290°E longitude, 5°N to 50°N latitude, and 0–12 km altitude. Substantial OCS and CS2 enhancements were observed for a great many air masses of Chinese and Japanese origin during TRACE-P. Over the western Pacific, mean mixing ratios of long-lived OCS and shorter-lived CS2 showed a gradual decrease by about 10% and a factor of 5–10, respectively, from the surface to 8–10 km altitude, presumably because land-based sources dominated their distribution during February through April 2001. The highest mean OCS and CS2 levels (580 and 20 pptv, respectively, based on 2.5° × 2.5° latitude bins) were observed below 2 km near the coast of Asia, at latitudes between 25°N and 35°N, where urban Asian outflow was strongest. Ratios of OCS versus CO for continental SE Asia were much lower compared to Chinese and Japanese signatures and were strongly associated with biomass burning/biofuel emissions. We present a new inventory of anthropogenic Asian emissions (including biomass burning) for OCS and CS2 and compare it to emission estimates based on regional relationships of OCS and CS2 to CO and CO2. The OCS and CS2 results for the two methods compare well for continental SE Asia and Japan plus Korea and also for Chinese CS2 emissions. However, it appears that the inventory underestimates Chinese emissions of OCS by about 30–100%. This difference may be related to the fact that we did not include natural sources such as wetland emissions in our inventory, although the contributions from such sources are believed to be at a seasonal low during the study period. Uncertainties in OCS emissions from Chinese coal burning, which are poorly characterized, likely contribute to the discrepancy.

[1] A comprehensive regional-scale chemical transport model, Sulfur Transport and Emissions Model 2001 (STEM-2K1), is employed to study dust outflows and their influence on regional chemistry in the high-dust Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) period, from 4–14 April 2001. In this period, dust storms are initialized in the Taklamagan and Gobi deserts because of cold air outbreaks, are transported eastward, and are often intensified by dust emitted from exposed soils as the front moves off the continent. Simulated dust agrees well with surface weather observations, satellite images, and the measurements of the C-130 aircraft. The C-130 aircraft observations of chemical constituents of the aerosol are analyzed for dust-rich and low-dust periods. In the submicron aerosol, dust-rich air masses have elevated ratios of ΔCa/ΔMg, ΔNH4+/ΔSO42−, and ΔNO3−/ΔCO (Δ represents the difference between observed and background concentrations). The impacts of heterogeneous reactions on dust involving O3, NO2, SO2, and HNO3 are studied by incorporating these reactions into the analysis. These reactions have significant influence on regional chemistry. For example, the low O3 concentrations in C-130 flight 6 can be explained only by the influence of heterogeneous reactions. In the near-surface layer, the modeled heterogeneous reactions indicated that O3, SO2, NO2, and HNO3 are decreased by up to 20%, 55%, 20%, and 95%, respectively, when averaged over this period. In addition, NO, HONO, and daytime OH can increase by 20%, 30%, and 4%, respectively, over polluted regions. When dust encounters fresh pollutants, these heterogeneous reactions can lead to a series of complex responses of the photochemical system. In addition, these reactions can alter the chemical-size distribution of the aerosol. Under heavy dust loadings, these reactions can lead to >20% of the sulfate and >70% of the nitrate being associated with the coarse fraction. The radiative influence of dust can also affect the photochemical system. For example, OH levels can decrease by 20% near surface. The dust radiative influence is shown to be weaker than the heterogeneous influence for most species.

[1] We present a global tabulation of black carbon (BC) and primary organic carbon (OC) particles emitted from combustion. We include emissions from fossil fuels, biofuels, open biomass burning, and burning of urban waste. Previous ‘‘bottom-up’’ inventories of black and organic carbon have assigned emission factors on the basis of fuel type and economic sector alone. Because emission rates are highly dependent on combustion practice, we consider combinations of fuel, combustion type, and emission controls and their prevalence on a regional basis. Central estimates of global annual emissions are 8.0 Tg for black carbon and 33.9 Tg for organic carbon. These estimates are lower than previously published estimates by 25–35%. The present inventory is based on 1996 fuel-use data, updating previous estimates that have relied on consumption data from 1984. An offset between decreased emission factors and increased energy use since the base year of the previous inventory prevents the difference between this work and previous inventories from being greater. The contributions of fossil fuel, biofuel, and open burning are estimated as 38%, 20%, and 42%, respectively, for BC, and 7%, 19%, and 74%, respectively, for OC. We present a bottom-up estimate of uncertainties in source strength by combining uncertainties in particulate matter emission factors, emission characterization, and fuel use. The total uncertainties are about a factor of 2, with uncertainty ranges of 4.3–22 Tg/yr for BC and 17–77 Tg/yr for OC. Low-technology combustion contributes greatly to both the emissions and the uncertainties. Advances in emission characterization for small residential, industrial, and mobile sources and topdown analysis combining field measurements and transport modeling with iterative inventory development will be required to reduce the uncertainties further. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0360 Atmospheric Composition and Structure: Transmission and scattering of radiation; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; KEYWORDS: emission, black carbon, organic carbon, fossil fuel, biofuel, biomass burning

[1] We report on mercury in the atmosphere of east Asia (Japan, Korea, and China) as measured from sea level to ∼7000 m during 16 research flights in the National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) C-130 aircraft during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) campaign (http://saga.pmel.noaa.gov/aceasia/). The air at all altitudes contained concentrations of atmospheric mercury above the global background. The atmosphere was highly stratified with plumes originating from massive dust storms carried out of China, from local industrial pollution, from volcanoes, and, less well defined, from biomass burning. Most often the air masses were mixtures, e.g., dust layers contained anthropogenic emissions or volcanic plumes were embedded in anthropogenic pollution; thus the total data set showed no significant correlations of gaseous mercury with the most common anthropogenic pollutants in the area (CO and SO2), but good correlations were observed for identifiable plumes. Highest mixing ratios for gaseous elemental mercury (GEM) were found in industrial plumes exiting China (∼6.3 ng/m3), Korea (∼3 ng/m3), and Japan (∼3 ng/m3). The core of the plume from Miyake Jima volcano contained ∼3.7 ng/m3 of GEM. Crustal mercury was also present, emitted and subsequently deposited during the outbreak of the spring dust storms. Some of the nondust aerosols contained soluble mercury in highly variable ratios with the gas-phase mercury contained in the same plume. Preliminary estimates for the export from China are 5–15 t of crustal mercury during the dust storms, ∼150 t/yr of gas-phase mercury from biomass/biofuel combustion, and ∼600 t/yr from industrial sources, mostly from coal combustion. Gaseous mercury is a useful tracer for industrial, volcanic, and biomass-burning sources, but in most cases, robust plume identification required one or more cotracers. Because of the inertness of GEM and the ease of its measurement it is well suited for the tracking of long-range transport.

[1] A comprehensive emission inventory with enhanced spatial and temporal resolution is used to help quantify the contribution from three source categories (fossil, biofuel, and biomass burning) during the NASA TRACE-P experiment. Daily biomass burning emissions are developed to support this analysis. Emissions of 27 species and their ratios, by sector, region, and source category are presented. The emission distributions and chemical composition are further analyzed using various statistical techniques. Using cluster analysis, the 27 chemical species are combined into 8 groups that have similar regional distribution, and 52 regions are assembled into 11 regional groups that have similar chemical composition. These groups are used in Chemical Mass Balance analysis to characterize air masses and to quantify the contribution of the three source categories to the observed species distributions. Five DC8 flights with 16 flight segments associated with outflow events are analyzed. In general, Asian outflow is a complex mixture of biofuel, biomass, and fossil sources. Flights in the post frontal regions at high latitudes and low altitudes have a high contribution of fossil fuel emissions. Flights in the warm sector of cold fronts are dominated by biomass burning contributions (about 70%). Biofuel contributions are high (about 70%) when air masses come from central China. The receptor model results are shown to be consistent with other 3-D chemical model sensitivity studies and analysis using ratios of indicator species (e.g., dK+/dSO42−, CH3CN/SOy, SOy/CO, and C2Cl4/CO).

[1] Measurements obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment are used in conjunction with regional modeling analysis to evaluate emission estimates for Asia. A comparison between the modeled values and the observations is one method to evaluate emissions. Based on such analysis it is concluded that the inventory performs well for the light alkanes, CO, ethyne, SO2, and NOx. Furthermore, based on model skill in predicting important photochemical species such as O3, HCHO, OH, HO2, and HNO3, it is found that the emissions inventories are of sufficient quality to support preliminary studies of ozone production. These are important finding in light of the fact that emission estimates for many species (such as speciated NMHCs and BC) for this region have only recently been estimated and are highly uncertain. Using a classification of the measurements built upon trajectory analysis, we compare observed species distributions and ratios of species to those modeled and to ratios estimated from the emissions inventory. It is shown that this technique can reconstruct a spatial distribution of propane/benzene that looks remarkably similar to that calculated from the emissions inventory. A major discrepancy between modeled and observed behavior is found in the Yellow Sea, where modeled values are systematically underpredicted. The integrated analysis suggests that this may be related to an underestimation of emissions from the domestic sector. The emission is further tested by comparing observed and measured species ratios in identified megacity plumes. Many of the model derived ratios (e.g., BC/CO, SOx/C2H2) fall within ∼25% of those observed and all fall outside of a factor of 2.5.

[1] Data obtained during the TRACE-P experiment is used to evaluate how well the CFORS/STEM-2K1 regional-scale chemical transport model is able to represent the aircraft observations. Thirty-one calculated trace gas and aerosol parameters are presented and compared to the in situ data. The regional model is shown to accurately predict many of the important features observed. The mean values of all the model parameters in the lowest 1 km are predicted within ±30% of the observed values. The correlation coefficients (R) for the meteorological parameters are found to be higher than those for the trace species. For example, for temperature, R > 0.98. Among the trace species, ethane, propane, and ozone show the highest values (0.8 < R < 0.9), followed by CO, SO2, and NOy. NO and NO2 had the lowest values (R < 0.4). Analyses of pollutant transport into the Yellow Sea by frontal events are presented and illustrate the complex nature of outflow. Biomass burning from SE Asia is transported in the warm conveyor belt at altitudes above ∼2 km and at latitudes below 30N. Outflow of pollution emitted along the east coast of China in the postfrontal regions is typically confined to the lower ∼2 km and results in high concentrations with plume-like features in the Yellow Sea. During these situations the model underpredicts CO and black carbon (among other species). An analysis of ozone production in this region is also presented. In and around the highly industrialized regions of East Asia, where fossil fuel usage dominates, ozone is NMHC-limited. South of ∼30–35N, ozone production is NOx-limited, reflecting the high NMHC/NOx ratios due to the large contributions to the emissions from biomass burning, biogenics sources, and biofuel usage in central China and SE Asia.