Source Of CO Emission Research Articles

North Korean CO emissions reconstruction using DMZ ground observations, TROPOMI space-borne data, and the CMAQ air quality model

Emission uncertainty in North Korea can act as an obstacle when developing air pollution management plans in the country and neighboring countries when the transboundary transport of air pollutants is considered. This study introduces a novel approach for adjusting and reallocating North Korean CO emissions, aiming to complement the limited observational and emissions data on the country's air pollutants. We utilized ground observations from demilitarized zone (DMZ) and vertical column density (VCD) data from a TROPOspheric Monitoring Instrument (TROPOMI), which were combined with the Community Multi-Scale Air Quality (CMAQ) chemistry transport model simulations. The Clean Air Support System (CAPSS) and Satellite Integrated Joint Monitoring of Air Quality (SIJAQ) emissions inventories served as the basis for our initial simulations. A two-step procedure was proposed to adjust both the emission intensity and the spatial distribution of emissions. First, air quality simulations were conducted to explore model sensitivity to changes in North Korean CO emissions with respect to ground concentrations. DMZ observations then constrained these simulations to estimate corresponding emission intensity. Second, the spatial structure of North Korean CO emission sources was reconstructed with the help of TROPOMI CO VCD distributions. Our two-step hybrid method outperformed individual emissions adjustment and spatial reallocation based solely on surface or satellite observations. Validation using ground observations from the Chinese Dandong site near the China-North Korea border revealed significantly improved model simulations when applying the updated CO emissions. The adjusted CO emissions were 10.9 times higher than those derived from the bottom-up emissions used in this study, highlighting the lack of information on North Korean pollutants and emission sources. This approach offers an efficient and practical solution for identifying potential missing emission sources when there is limited on-site information about air quality on emissions.

Evolution of the Outflow in the Water Fountain Source IRAS 18043–2116* *Released on 2021 March 1.

We present the spectral and spatial evolution of H2O masers associated with the water fountain source IRAS 18043−2116, found in observations with the Nobeyama 45 m Telescope and the Australia Telescope Compact Array. We have found new highest-velocity components of the H2O masers (at the redshifted side V LSR ≃ 376 km s−1 and at the blueshifted side V LSR ≃ −165 km s−1), and the resulting velocity spread of ≃540 km s−1 breaks the speed record of fast jets/outflows in this type of sources. The locations of those components have offsets from the axis joining the two major maser clusters, indicating a large opening angle of the outflow (∼60°). The evolution of the maser cluster separation of ∼2.9 mas yr−1 and the compact (∼0.″2) CO emission source mapped with the Atacama Large Millimeter-submillimeter Array suggest a very short (∼30 yr) timescale of the outflow. We also confirmed an increase in the flux density of the 22 GHz continuum source. The properties of the jet and the continuum sources and their possible evolution in the transition to the planetary nebula phase are further discussed.

Analysis of source distribution of high carbon monoxide events using airborne and surface observations in Korea

Carbon monoxide (CO) is a key tracer of anthropogenic pollution, and it indirectly affects climate change. Anmyeon-do (AMY, 36.54° N, 126.33° E), a World Meteorological Organization/Global Atmosphere Watch Program (WMO/GAW) regional background station in Korea, provides continuous observations of CO mole fractions at the surface and vertical profiles within 0.5–9 km that are also collected by aircraft campaigns. The vertical profiles collected in 2019 were analyzed using meteorological parameters such as vertical velocity and boundary layer height (BLH), and a strong relationship was observed among them; however, the vertical distribution, which was influenced by unexpected strong pollution plumes, did not exhibit a strong relationship with vertical velocity and BLH. On November 16, we captured a strong CO signal within the boundary layer and at approximately 2 km above the BLH, where vertical profiles of the aerosol scattering coefficient at 550 nm were simultaneously observed with the same vertical structure. To identify the origins and source types of the stratification of the pollution plume for CO and aerosol, we also analyzed surface in situ observations of particle size distributions and reactive gases (NOx, O3, and SO2) as well as the column averaged dry-air mole fraction of carbon monoxide (XCO) and measurements of aerosol optical depth obtained from the tropospheric monitoring instrument (TROPOMI) and moderate resolution imaging spectroradiometer (MODIS) satellite, respectively. The high CO event within the BLH, including observations at the surface site, was attributed to domestic burning sources. Convective uplifting of industrial fossil fuel emissions from eastern China was responsible for the high CO dry mole fraction in the low free troposphere (FT) and the elevated aerosol scattering coefficient. Statistical analyses of one-year surface in situ observations of CO reveal that CO-emission sources from eastern China contributed to extremely high CO spikes (≥80th percentile of CO or ≥ 350 ppb, approximately) in 2019. Therefore, we concluded that emissions from eastern China have a potentially leading role in the observed high pollution events at the surface and the lower FT over the AMY station in 2019. The increase in ground temperature, with the acceleration of the global warming process, can intensify the convective uplifting of pollution plumes from emission source regions to FT over East Asian regions. In addition, such an occurrence of the stratification of the atmospheric pollution plume in the troposphere should be considered in future studies on radiative forcing to improve air-quality forecasting in this region.

A SUBLIME 3D Model for Cometary Coma Emission: The Hypervolatile-rich Comet C/2016 R2 (PanSTARRS)

Abstract The coma of comet C/2016 R2 (PanSTARRS) is one of the most chemically peculiar ever observed, in particular due to its extremely high CO/H2O and N 2 + /H2O ratios, and unusual trace volatile abundances. However, the complex shape of its CO emission lines, as well as uncertainties in the coma structure and excitation, has lead to ambiguities in the total CO production rate. We performed high-resolution, spatially, spectrally, and temporally resolved CO observations using the James Clerk Maxwell Telescope and Submillimeter Array to elucidate the outgassing behavior of C/2016 R2. Results are analyzed using a new, time-dependent, three-dimensional radiative transfer code (SUBlimating gases in LIME; SUBLIME, based on the open-source version of the LIne Modeling Engine), incorporating for the first time, accurate state-to-state collisional rate coefficients for the CO–CO system. The total CO production rate was found to be in the range of (3.8 − 7.6) × 1028 s−1 between 2018 January 13 and February 1 (at r H = 2.8–2.9 au), with a mean value of (5.3 ± 0.6) × 1028 s−1. The emission is concentrated in a near-sunward jet, with a half-opening angle of ∼62° and an outflow velocity of 0.51 ± 0.01 km s−1, compared to 0.25 ± 0.01 km s−1 in the ambient (and nightside) coma. Evidence was also found for an extended source of CO emission, possibly due to icy grain sublimation around 1.2 × 105 km from the nucleus. Based on the coma molecular abundances, we propose that the nucleus ices of C/2016 R2 can be divided into a rapidly sublimating apolar phase, rich in CO, CO2, N2, and CH3OH, and a predominantly frozen (or less abundant), polar phase containing more H2O, CH4, H2CO, and HCN.

CO emission regularity and its influencing factors in a fully mechanized caving face

To explore the problem of CO concentration overrun in fully mechanized caving faces, a multiphysical field coupling model of CO emission regularity was established in this study based on the gas flow theory, gas concentration field theory, and heat transfer theory. Taking the 014N1−1 working face of the No. 1 coal seam in Ruian coal mine as the research object, the model was applied to simulate the CO concentration in the fully mechanized caving face. The simulation results were found to be consistent with the field detection results. Based on the simulation results, the effects of advancing speed and wind velocity on the CO emissions in the gob and the CO concentration distribution in the working face were analyzed. The results showed that, the lower the wind velocity, the greater the CO emissions. With increasing advancing speed, the CO emissions in the gob first increased, reached maximum, and then decreased. The production conditions were found to be most suitable when the advancing speed and wind velocity were 2 and 1.8 m/s, respectively. Moreover, the CO emission characteristics of the fully mechanized caving face under the conditions of periodic roof weighting, production process, and atmospheric pressure change were monitored and analyzed. We verified the presence of CO in the coal seam and its emission with the progress of coal seam mining. Our results will be useful in the research and analysis of CO emission source, emission regularity, and overrun warning in fully mechanized working faces.

ANALYSIS OF CO EMISSION OF HETEROGENEOUS TRAFFIC USING CALINE 4 AT DAYA PASSENGER TERMINAL IN MAKASSAR INDONESIA

Motor vehicles have been a primary source of CO emissions in many major cities in the world,including in Makassar, Indonesia. The increasing of the motor vehicle under heterogeneous traffic conditionon the Daya Passenger Terminal (DPT) leads to the air pollution rise that emitted by the vehicles asconsequently. This study aims to predict the quantity and model of CO emissions distribution using the Caline4 in DPT. In 2016, vehicle volume and CO emission data collection were conducted on 10 receptors in DPTand meteorological data obtained from Indonesia Agency in the Makassar region. The results are the emissionstend to be the same in 2016 and 2017 with the largest amount of CO emissions in receptor 9 and compared to2018 decrease by 33%. The CO emission distribution model is highly influenced by wind speed and dominantdirection and has different models, which are 5, 3, 4 in 2016, 2017, and 2018 respectively. For further research,this study is particularly useful as preliminary information related to air quality mitigation.

A DECADAL ANALYSIS AND SENSITIVITY STUDY USING MOPITT CO COLUMNS OVER ASIA

Abstract. Biomass burning and urbanization are both significant sources of CO emissions and atmospheric loadings in the real environment. The sources of CO are due to incomplete combustion, on one hand of biomass from agriculture or forest clearing, and on the other hand from coal, oil, gas, and other similar materials. However, the spatial and temporal underlying properties and patterns are quite different between these two types of source regions, with urban regions having a relatively constant source of CO emissions, with only short term concentration fluctuations due to local meteorology. On the other hand, in biomass burning regions, the emissions themselves tend to be highly concentrated over a short burning period, and very low otherwise. We hence present a new technique to classify and quantify biomass burning regions and urban regions based on an objective analysis of the CO total column measurements from the MOPITT satellite. By using all of the data from 2000–2016, in connection with averages and standard deviation cutoffs, we successfully determine these regions. By performing a sensitivity analysis, in connection with additional ground-based measurements, we determine that the ideal cutoffs for the mean column loading and standard deviation of the column loading 28 × 1017 mol/cm2 and 6 × 1017 mol/cm2 respectively. These results are capable of representing known urban regions and biomass burning regions well throughout China, Southeast Asia, and South Asia, specifically including Beijing, Hebei, Shandong, Jiangsu, Anhui, Hunan, Guangdong, and Bangkok on one hand, and Northeastern India, Myanmar, Laos, Northern Thailand, and Vietnam on the other hand. A detailed analysis of the time series over the different classified regions show that while the urban areas have a much higher annual value, and a relatively long peak time, that their maximum is never as high as the peaks in the biomass burning regions, and that these peaks in the biomass burning regions are extremely short in duration, although they occur annually or bi-annually. Finally, we have not been able to obtain a statistically relevant decreasing trend, as others have found, making CO possibly an interesting species for future studies.

The Arizona Radio Observatory CO Mapping Survey of Galactic Molecular Clouds. VI. The Cep OB3 Cloud (Cepheus B and C) in CO J = 2–1, 13CO J = 2–1, and CO J = 3–2

Abstract We present (1) new fully sampled maps of CO and J = 2–1 emission and CO J = 3–2 emission toward the molecular clouds Cep B and C, associated with the Cep OB3 association; (2) a map of extinction, A V , derived from IR colors of background stars; and (3) the distribution of young stellar objects (YSOs) over the same field as the molecular maps. An LTE analysis of the CO and maps yields the distribution of molecular column densities and temperatures. Substantial variations are evident across the clouds; smaller subregions show correlations between molecular properties and dust extinction, consistent with a picture of outer photodissociation regions with a layer of CO-dark molecular gas, a CO self-shielded interior, and an inner cold dense region where CO is largely depleted onto grains. Comparing the distribution of YSOs with molecular gas surface density shows a power-law relation very similar in slope to that for the giant molecular cloud associated with the H ii region Sh2-235 from a previous paper in this series that employed the same methodology. We note the presence of several compact, isolated CO emission sources in the J = 3–2 maps. The gas temperature and velocity dispersion yield a map of the sonic Mach number, which varies across the cloud but always exceeds unity, confirming the pervasiveness of supersonic turbulence over length scales ≳0.1 pc (the map resolution). We also compute a J = 2–1 CO X-factor that varies with position but is, on average, within 20% of the Galactic average derived from CO J = 1–0 observations.

권역별 대기오염물질의 연도별 배출 특성 분석

Using the CAPSS emissions data, we analysed changes and reasons in the annual air pollutant emission trends from 1999 to 2014. The CO emissions in the metropolitan area decreased steadily since 2001, when the latest model year of automobiles and high efficiency fuel were applied. However, other regions have not changed significantly in annual emissions. NOx emissions continued to increase since 2003, and unchanged after the decline in 2007. SOx emissions are steadily declining due to the supply of low sulfur oil. The PM10 and PM2.5 emissions were repeatedly affected by the influence of motor vehicles activities in the metropolitan area. In Gangwon and Chungcheong Provinces, emissions are increasing according to the use of coal in the manufacturing sector. And VOC and NH3 emissions are increasing steadily every year. The major CO emission sources was automobiles in the metropolitan area. However, agricultural residue burning was the biggest CO sources in the Chungchong, Honam and Yeongnam Provinces. The major sources of NOx emissions differ from region to region. In the Metropolitan area, Honam and Yeongnam region, the truck was the largest emitter of NOx. However, the cement kiln was the largest producer of NOx in Gangwon region, and the power plant is the largest emitter in Chungcheong Provinces.

ディーゼル燃焼のCO 排出要因解析（第2報）

ディーゼル燃焼のCO 排出要因解析（第2報）

ディーゼル燃焼のCO 排出要因解析（第３報) − CO 排出低減方法とその検証 −

ディーゼル燃焼のCO 排出要因解析（第３報) − CO 排出低減方法とその検証 −

Seasonal variability of surface and column carbon monoxide over the megacity Paris, high-altitude Jungfraujoch and Southern Hemispheric Wollongong stations

Abstract. This paper studies the seasonal variation of surface and column CO at three different sites (Paris, Jungfraujoch and Wollongong), with an emphasis on establishing a link between the CO vertical distribution and the nature of CO emission sources. We find the first evidence of a time lag between surface and free tropospheric CO seasonal variations in the Northern Hemisphere. The CO seasonal variability obtained from the total columns and free tropospheric partial columns shows a maximum around March–April and a minimum around September–October in the Northern Hemisphere (Paris and Jungfraujoch). In the Southern Hemisphere (Wollongong) this seasonal variability is shifted by about 6 months. Satellite observations by the IASI–MetOp (Infrared Atmospheric Sounding Interferometer) and MOPITT (Measurements Of Pollution In The Troposphere) instruments confirm this seasonality. Ground-based FTIR (Fourier transform infrared) measurements provide useful complementary information due to good sensitivity in the boundary layer. In situ surface measurements of CO volume mixing ratios at the Paris and Jungfraujoch sites reveal a time lag of the near-surface seasonal variability of about 2 months with respect to the total column variability at the same sites. The chemical transport model GEOS-Chem (Goddard Earth Observing System chemical transport model) is employed to interpret our observations. GEOS-Chem sensitivity runs identify the emission sources influencing the seasonal variation of CO. At both Paris and Jungfraujoch, the surface seasonality is mainly driven by anthropogenic emissions, while the total column seasonality is also controlled by air masses transported from distant sources. At Wollongong, where the CO seasonality is mainly affected by biomass burning, no time shift is observed between surface measurements and total column data.

Variation Trend and Characteristics of Anthropogenic CO Column Content in the Atmosphere over Beijing and Moscow

The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing, China, and Moscow, Russia, during 1992-2012. Some specific variation char- acteristics and long-term variation trends of the CO col- umn content in the atmosphere in these regions are dis- cussed. An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992-2012, while for the Moscow region, it de- creases yearly by about 1.4% for the same period. High CO concentrations appear quite frequently in Beijing, but much less frequently in Moscow, except during the natu- ral fire events in summer 2010. From back trajectory analysis, the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.

Diffusion factors of street canyon pollutants in the cold winter of Xi’an city based on back propagation neural network analysis

The factors affecting pollutant diffusion in street canyons during the cold winter of Xi’an City, China, were analysed by measuring the near-surface atmospheric parameters at the height of 1.5 m from ground surface and the aspect ratios (ARs) of 40 street canyons. SPSS software was adopted to obtain eight multiple regression models, including the city street locations, street orientations and street widths. A back propagation neural network was employed to obtain the weight of the factors and their sensitivities. The near-surface atmospheric parameters, leaf area index (LAI) and street canyon AR in the pedestrian area could have an effect on the pollution in street canyons. CO diffusion is strongly influenced by near-surface atmospheric parameters, such as wind velocity, air temperature and relative humidity (RH), together with the CO emission source intensity, street canyon AR and LAI. Their weights were 0.360, 0.275, 0.137, 0.113, 0.068 and 0.047. In particular, near-surface atmospheric parameters were shown to be affected by the street orientation in the city.

NIR SPECTROSCOPY OF THE HAeBe STAR HD 100546. III. FURTHER EVIDENCE OF AN ORBITING COMPANION?

We report high resolution NIR spectroscopy of CO and OH emission from the Herbig Be star HD100546. We discuss how our results bear striking resemblance to several theoretically predicted signposts of giant planet formation. The properties of the CO and OH emission lines are consistent with our earlier interpretation that these diagnostics provide indirect evidence for a companion that orbits the star close to the disk wall (at ~13au). The asymmetry of the OH spectral line profiles and their lack of time variability are consistent with emission from gas in an eccentric orbit at the disk wall that is approximately stationary in the inertial frame. The time variable spectroastrometric properties of the CO v=1-0 emission line point to an orbiting source of CO emission with an emitting area similar to that expected for a circumplanetary disk (~0.1au^2) assuming the CO emission is optically thick. We also consider a counterhypothesis to this interpretation, namely that the variable CO emission arises from a bright spot on the disk wall. We conclude with a brief suggestion of further work that can distinguish between these scenarios.

Variation Trend and Characteristics of Anthropogenic CO Column Content in the Atmosphere over Beijing and Moscow

The anthropogenic CO column content in the atmosphere is derived from measurements with infrared grating spectrometers in Beijing,China,and Moscow,Russia,during 1992–2012.Some specific variation characteristics and long-term variation trends of the CO column content in the atmosphere in these regions are discussed.An evident variation trend of anthropogenic CO in the atmosphere for the Beijing region is not observed during 1992–2012,while for the Moscow region,it decreases yearly by about 1.4% for the same period.High CO concentrations appear quite frequently in Beijing,but much less frequently in Moscow,except during the natural fire events in summer 2010.From back trajectory analysis,the high CO concentration observed in Beijing can be attributed to the intensive CO emission sources in its surrounding areas.

HIGH-RESOLUTION NEAR-INFRARED SPECTROSCOPY OF HD 100546. II. ANALYSIS OF VARIABLE ROVIBRATIONAL CO EMISSION LINES

We present observations of rovibrational CO in HD 100546 from four epochs spanning January 2003 through December 2010. We show that the equivalent widths of the CO lines vary during this time period with the v=1-0 CO lines brightening more than the UV fluoresced lines from the higher vibrational states. While the spectroastrometric signal of the hot band lines remains constant during this period, the spectroastrometric signal of the v=1--0 lines varies substantially. At all epochs, the spectroastrometric signals of the UV fluoresced lines are consistent with the signal one would expect from gas in an axisymmetric disk. In 2003, the spectroastrometric signal of the v=1-0 P26 line was symmetric and consistent with emission from an axisymmetric disk. However, in 2006, there was no spatial offset of the signal detected on the red side of the profile, and in 2010, the spectroastrometric offset was yet more strongly reduced toward zero velocity. A model is presented that can explain the evolution of the equivalent width of the v=1-0 P26 line and its spectroastrometric signal by adding to the system a compact source of CO emission that orbits the star near the inner edge of the disk. We hypothesize that such emission may arise from a circumplanetary disk orbiting a gas giant planet near the inner edge of the circumstellar disk. We discuss how this idea can be tested observationally and be distinguished from an alternative interpretation of random fluctuations in the disk emission.

EE2-2 Analysis of CO Emission Sources in Diesel Combustion with Multiple Injections(EE: Exhaust Emissions and Measurement,General Session Papers)

EE2-2 Analysis of CO Emission Sources in Diesel Combustion with Multiple Injections(EE: Exhaust Emissions and Measurement,General Session Papers)

FT8-3 Advanced Low Emissions Combustor Design

Pratt and Whitney developed a novel water-injected industrial gas turbine combustor liner design that has demonstrated significant reduction in CO emissions when compared with typical film-cooled combustor designs. The CO reduction demonstrated in a prototype test shows that the CO quenching due to cooler film temperatures near the liner wall is a significant source of CO emissions in a conventional water-injected combustor operating on natural gas fuel. This finding paved the way for a combustor design that reduces CO emissions while still maintaining low levels of NOx emissions. This design also has potential for lower NOx since the low CO emissions characteristic enables increased water injection. This paper presents the emissions characteristic measured on prototype hardware and the design of the engine hardware for future validation. Significant reduction in gaseous emissions was demonstrated with the testing of a prototype at the United Technologies Research Center in East Hartford, CT. This reduction in emissions compared with the baseline film-cooled design for a given operating condition has many benefits to the customer, including the reduced need for exhaust catalyst cleanup and extended operating times while still meeting site permits specified in CO tons per year. Other benefits may include the ability to guarantee lower NOx emissions through increased water injection for the current CO emissions output.

On-road vehicle emission inventory and its uncertainty analysis for Shanghai, China

As vehicle population and activity increase, vehicle emissions are becoming the most predominant source of air pollution in Shanghai, China. It has become important to accurately estimate the traffic emissions in this city. This paper presents a bottom–up approach based on the International Vehicle Emission (IVE) model to develop the vehicle emission inventory for Shanghai. The results show that the total emissions of CO, VOC, NO X and PM from vehicles in Shanghai in 2004 were 57.06 × 10 4 t, 7.75 × 10 4 t, 9.20 × 10 4 t and 0.26 × 10 4 t, respectively. About 20% of the total emissions were emitted during the cold start period. Heavy-duty vehicles such as trucks and buses contributed over half of NO X and PM. Motorcycles and mopeds provided 45.0% of VOC and 36.3% of PM. Light-duty vehicles are the main source of CO emissions. An assessment of vehicle emissions by time of day and road type was also discussed. The three peak emission periods accounted for 54% to 56% of the total emissions during the day and more than 50% of the total emissions were emitted on the arterial roads. Finally, the study focused on the uncertainty analysis of two critical factors: emission factors and the estimate of the total Vehicle Kilometers Traveled (VKT). The analysis indicates that the emission factors calculated in this paper are close to those factors measured during on-road testing, and the difference between the VKT used in this paper and other calculations is less than 10%.