scholarly journals Modelling constraints on the emission inventory and on vertical dispersion for CO and SO<sub>2</sub> in the Mexico City Metropolitan Area using Solar FTIR and zenith sky UV spectroscopy

2007 ◽  
Vol 7 (3) ◽  
pp. 781-801 ◽  
Author(s):  
B. de Foy ◽  
W. Lei ◽  
M. Zavala ◽  
R. Volkamer ◽  
J. Samuelsson ◽  
...  
Keyword(s):  
Power Plant ◽  
Mexico City ◽  
Urban Areas ◽  
Emission Inventory ◽  
Uv Spectroscopy ◽  
Transport Processes ◽  
Point Sources ◽  
Large Power ◽  
Vertical Dispersion ◽  
Current Emission

Abstract. Emissions of air pollutants in and around urban areas lead to negative health impacts on the population. To estimate these impacts, it is important to know the sources and transport mechanisms of the pollutants accurately. Mexico City has a large urban fleet in a topographically constrained basin leading to high levels of carbon monoxide (CO). Large point sources of sulfur dioxide (SO2) surrounding the basin lead to episodes with high concentrations. An Eulerian grid model (CAMx) and a particle trajectory model (FLEXPART) are used to evaluate the estimates of CO and SO2 in the current emission inventory using mesoscale meteorological simulations from MM5. Vertical column measurements of CO are used to constrain the total amount of emitted CO in the model and to identify the most appropriate vertical dispersion scheme. Zenith sky UV spectroscopy is used to estimate the emissions of SO2 from a large power plant and the Popocatépetl volcano. Results suggest that the models are able to identify correctly large point sources and that both the power plant and the volcano impact the MCMA. Modelled concentrations of CO based on the current emission inventory match observations suggesting that the current total emissions estimate is correct. Possible adjustments to the spatial and temporal distribution can be inferred from model results. Accurate source and dispersion modelling provides feedback for development of the emission inventory, verification of transport processes in air quality models and guidance for policy decisions.

scholarly journals Modelling constraints on the emission inventory and on vertical diffusion for CO and SO<sub>2</sub> in the Mexico City Metropolitan Area using Solar FTIR and zenith sky UV spectroscopy

2006 ◽  
Vol 6 (4) ◽  
pp. 6125-6181 ◽  
Author(s):  
B. de Foy ◽  
W. Lei ◽  
M. Zavala ◽  
R. Volkamer ◽  
J. Samuelsson ◽  
...  
Keyword(s):  
Power Plant ◽  
Mexico City ◽  
Urban Areas ◽  
Emission Inventory ◽  
Uv Spectroscopy ◽  
Transport Processes ◽  
Point Sources ◽  
Vertical Diffusion ◽  
Large Power ◽  
Current Emission

Abstract. Emissions of air pollutants in and around urban areas lead to negative health impacts on the population. To estimate these impacts, it is important to know the sources and transport mechanisms of the pollutants accurately. Mexico City has a large urban fleet in a topographically constrained basin leading to high levels of carbon monoxide (CO). Large point sources of sulfur dioxide (SO2) surrounding the basin lead to episodes with high concentrations. An Eulerian grid model (CAMx) and a particle trajectory model (FLEXPART) are used to evaluate the estimates of CO and SO2 in the current emission inventory using mesoscale meteorological simulations from MM5. Vertical column measurements of CO are used to constrain the total amount of emitted CO in the model and to identify the most appropriate vertical diffusion scheme. Zenith sky UV spectroscopy is used to estimate the emissions of SO2 from a large power plant and the Popocatépetl volcano. Results suggest that the models are able to identify correctly large point sources and that both the power plant and the volcano impact the MCMA. Modelled concentrations of CO based on the current emission inventory match observations suggesting that the current total emissions estimate is correct. Possible adjustments to the spatial and temporal distribution can be inferred from model results. Accurate source and dispersion modelling provides feedback for development of the emission inventory, verification of transport processes in air quality models and guidance for policy decisions.

scholarly journals Impact of model resolution on chemical ozone formation in Mexico City: application of the WRF-Chem model

2010 ◽  
Vol 10 (18) ◽  
pp. 8983-8995 ◽  
Author(s):  
X. Tie ◽  
G. Brasseur ◽  
Z. Ying
Keyword(s):  
Mexico City ◽  
Urban Areas ◽  
Air Pollutants ◽  
Emission Inventory ◽  
Meteorological Conditions ◽  
Transport Processes ◽  
Ozone Production ◽  
Model Resolution ◽  
Coarse Resolution ◽  
Photochemical Ozone

Abstract. The resolution of regional chemical/dynamical models has important effects on the calculation of the distributions of air pollutants in urban areas. In this study, the sensitivity of air pollutants and photochemical ozone production to different model resolutions is assessed by applying a regional chemical/dynamical model (version 3 of Weather Research and Forecasting Chemical model – WRF-Chemv3) to the case of Mexico City. The model results with 3, 6, 12, and 24 km resolutions are compared to local surface measurements of CO, NOx, and O3. The study shows that the model resolutions of 3 and 6 km provide reasonable simulations of surface CO, NOx, and O3 concentrations and of diurnal variations. The model tends to underestimate the measurements when the resolution is reduced to 12 km or less. The calculated surface CO, NOx, and O3 concentrations at 24 km resolution are significantly lower than measured values. This study suggests that the ratio of the city size to the threshold resolution is 6 to 1, and that this ratio can be considered as a test value in other urban areas for model resolution setting. There are three major factors related to the effects of model resolution on the calculations of O3 and O3 precursors, including; (1) the calculated meteorological conditions, (2) the spatial distribution for the emissions of ozone precursors, and (3) the non-linearity in the photochemical ozone production. Model studies suggest that, for the calculations of O3 and O3 precursors, spatial resolutions (resulting from different meteorological condition and transport processes) have larger impacts than the effect of the resolution associated with emission inventories. The model shows that, with coarse resolution of emission inventory (24 km) and high resolution for meteorological conditions (6 km), the calculated CO and O3 are considerably improved compared to the results obtained with coarse resolution for both emission inventory and meteorological conditions (24 km). The resolution of the surface emissions has important effects on the calculated concentration fields, but the effects are smaller than those resulting from the model resolution. This study also suggests that the effect of model resolution on O3 precursors leads to important impacts on the photochemical formation of ozone. This results directly from the non-linear relationship between O3 formation and O3 precursor concentrations. Finally, this study suggests that, considering the balance between model performance and required computation time on current computers, the 6 km resolution is an optimal resolution for the calculation of ozone and its precursors in urban areas like Mexico City.

scholarly journals NH<sub>3</sub> emissions from large point sources derived from CrIS and IASI satellite observations

2019 ◽  
Author(s):  
Enrico Dammers ◽  
Chris A. McLinden ◽  
Debora Griffin ◽  
Mark W. Shephard ◽  
Shelley Van Der Graaf ◽  
...  
Keyword(s):  
Human Health ◽  
Reactive Nitrogen Species ◽  
Emission Inventory ◽  
Point Sources ◽  
Satellite Observations ◽  
Order Of Magnitude ◽  
Short And Long Term ◽  
Current Emission ◽  
Human Kind

Abstract. Ammonia (NH3) is an essential reactive nitrogen species in the biosphere and through its use in agriculture in the form of fertilizer important for sustaining human kind. The current emission levels however, are up to four times higher than in the previous century and continue to grow with uncertain consequences to human health and the environment. While NH3 at its current levels is a hazard to the environmental and human health the atmospheric budget is still highly uncertain, which is a product of an overall lack of measurements. The capability to measure NH3 with satellites has opened up new ways to study the atmospheric NH3 budget. In this study we present the first estimates of NH3 emissions, lifetimes, and plume widths from large (> ~ 5 kt/yr) agricultural and industrial point sources from CrIS satellite observations across the globe with a consistent methodology. The same methodology is also applied to the IASI (A and B) satellite observations and we show that the satellites typically provide comparable results that are within the uncertainty of the estimates. The computed NH3 lifetime for large point sources is on average 2.35 ± 1.16 hours. For the 249 sources with emission levels detectable by the CrIS satellite, there are currently 55 locations missing (or underestimated by more than an order of magnitude) from the current HTAPv2 emission inventory, and only 72 locations with emissions within a factor 2 compared to the inventories. We find a total of 5622 kt/yr, for the sources analyzed in this study, which is equivalent to a factor ~ 2.5 between the CrIS estimated and HTAPv2 emissions. Furthermore, the study shows that it is possible to accurately detect short and long-term changes in emissions, demonstrating the possibility of using satellite observed NH3 to constrain emission inventories.

scholarly journals Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

2012 ◽  
Vol 12 (10) ◽  
pp. 4429-4447 ◽  
Author(s):  
S. W. Wang ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
R. V. Martin ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Emission Inventory ◽  
Transport Model ◽  
Nox Emission ◽  
Nox Emissions ◽  
Large Power ◽  
Power Plant Emissions ◽  
Tropospheric No2 ◽  
Plant Emissions

Abstract. Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.

scholarly journals A global map of emission clumps for future monitoring of fossil fuel CO<sub>2</sub> emissions from space

2019 ◽  
Vol 11 (2) ◽  
pp. 687-703 ◽  
Author(s):  
Yilong Wang ◽  
Philippe Ciais ◽  
Grégoire Broquet ◽  
François-Marie Bréon ◽  
Tomohiro Oda ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Land Surface ◽  
Urban Areas ◽  
Power Plants ◽  
Fossil Fuel ◽  
Large Fraction ◽  
Point Sources ◽  
Bottom Up ◽  
Large Power ◽  
Data Product

Abstract. A large fraction of fossil fuel CO2 emissions emanate from “hotspots”, such as cities (where direct CO2 emissions related to fossil fuel combustion in transport, residential, commercial sectors, etc., excluding emissions from electricity-producing power plants, occur), isolated power plants, and manufacturing facilities, which cover a small fraction of the land surface. The coverage of all high-emitting cities and point sources across the globe by bottom-up inventories is far from complete, and for most of those covered, the uncertainties in CO2 emission estimates in bottom-up inventories are too large to allow continuous and rigorous assessment of emission changes (Gurney et al., 2019). Space-borne imagery of atmospheric CO2 has the potential to provide independent estimates of CO2 emissions from hotspots. But first, what a hotspot is needs to be defined for the purpose of satellite observations. The proposed space-borne imagers with global coverage planned for the coming decade have a pixel size on the order of a few square kilometers and a XCO2 accuracy and precision of <1 ppm for individual measurements of vertically integrated columns of dry-air mole fractions of CO2 (XCO2). This resolution and precision is insufficient to provide a cartography of emissions for each individual pixel. Rather, the integrated emission of diffuse emitting areas and intense point sources is sought. In this study, we characterize area and point fossil fuel CO2 emitting sources which generate coherent XCO2 plumes that may be observed from space. We characterize these emitting sources around the globe and they are referred to as “emission clumps” hereafter. An algorithm is proposed to identify emission clumps worldwide, based on the ODIAC global high-resolution 1 km fossil fuel emission data product. The clump algorithm selects the major urban areas from a GIS (geographic information system) file and two emission thresholds. The selected urban areas and a high emission threshold are used to identify clump cores such as inner city areas or large power plants. A low threshold and a random walker (RW) scheme are then used to aggregate all grid cells contiguous to cores in order to define a single clump. With our definition of the thresholds, which are appropriate for a space imagery with 0.5 ppm precision for a single XCO2 measurement, a total of 11 314 individual clumps, with 5088 area clumps, and 6226 point-source clumps (power plants) are identified. These clumps contribute 72 % of the global fossil fuel CO2 emissions according to the ODIAC inventory. The emission clumps is a new tool for comparing fossil fuel CO2 emissions from different inventories and objectively identifying emitting areas that have a potential to be detected by future global satellite imagery of XCO2. The emission clump data product is distributed from https://doi.org/10.6084/m9.figshare.7217726.v1.

Emissions of heavy metals into river basins of Germany

2003 ◽  
Vol 47 (7-8) ◽  
pp. 251-257 ◽  
Author(s):  
U. Scherer ◽  
S. Fuchs ◽  
H. Behrendt ◽  
T. Hillenbrand
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Urban Areas ◽  
Municipal Wastewater ◽  
River Basins ◽  
Large River ◽  
Transport Processes ◽  
Point Sources ◽  
Geographical Information ◽  
Large River Basins

The input of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) into the large river basins of Germany via various point and diffuse pathways were estimated for the period of 1985 through 2000. To quantify the emissions via point sources a nationwide survey on heavy metal data of municipal wastewater treatment plants and industrial direct discharges was carried out. The input via diffuse pathways was calculated using an adapted version of the model MONERIS. This model accounts for the significant transport processes, and it includes a Geographical Information System (GIS) that provides digital maps as well as extensive statistical information. For a comparison of the calculated heavy metal emission with the measured heavy metal load at monitoring stations the losses of heavy metals due to retention processes within the river systems have to be considered. Therefore heavy metal retention was calculated according to the retention functions given by Vink and Behrendt. For the large river basins a good correspondence could be found between estimated and measured heavy metal loads in rivers. The total emission into the North Sea decreased for each metal during the period of 1985 to 2000. The reduction varies between 87% for Hg and 41% for Ni mainly caused by the decline via point sources. Today's emissions of heavy metals into river basins of Germany are dominated by the input via diffuse pathways. The most important diffuse emission pathways are “paved urban areas” and “erosion”.

scholarly journals High-resolution inventory of technologies, activities, and emissions of coal-fired power plants in China from 1990 to 2010

2015 ◽  
Vol 15 (23) ◽  
pp. 13299-13317 ◽  
Author(s):  
F. Liu ◽  
Q. Zhang ◽  
D. Tong ◽  
B. Zheng ◽  
M. Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Power Plant ◽  
Power Plants ◽  
Emission Inventory ◽  
Control Measures ◽  
Growth Trend ◽  
Large Power ◽  
Unit Level ◽  
Power Plant Emissions ◽  
Plant Emissions

Abstract. This paper, which focuses on emissions from China's coal-fired power plants during 1990–2010, is the second in a series of papers that aims to develop a high-resolution emission inventory for China. This is the first time that emissions from China's coal-fired power plants were estimated at unit level for a 20-year period. This inventory is constructed from a unit-based database compiled in this study, named the China coal-fired Power plant Emissions Database (CPED), which includes detailed information on the technologies, activity data, operation situation, emission factors, and locations of individual units and supplements with aggregated data where unit-based information is not available. Between 1990 and 2010, compared to a 479 % growth in coal consumption, emissions from China's coal-fired power plants increased by 56, 335, and 442 % for SO2, NOx, and CO2, respectively, and decreased by 23 and 27 % for PM2.5 and PM10 respectively. Driven by the accelerated economic growth, large power plants were constructed throughout the country after 2000, resulting in a dramatic growth in emissions. The growth trend of emissions has been effectively curbed since 2005 due to strengthened emission control measures including the installation of flue gas desulfurization (FGD) systems and the optimization of the generation fleet mix by promoting large units and decommissioning small ones. Compared to previous emission inventories, CPED significantly improved the spatial resolution and temporal profile of the power plant emission inventory in China by extensive use of underlying data at unit level. The new inventory developed in this study will enable a close examination of temporal and spatial variations of power plant emissions in China and will help to improve the performances of chemical transport models by providing more accurate emission data.

scholarly journals High-resolution inventory of technologies, activities, and emissions of coal-fired power plants in China from 1990 to 2010

2015 ◽  
Vol 15 (13) ◽  
pp. 18787-18837 ◽  
Author(s):  
F. Liu ◽  
Q. Zhang ◽  
D. Tong ◽  
B. Zheng ◽  
M. Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Power Plant ◽  
Power Plants ◽  
Emission Inventory ◽  
Control Measures ◽  
Growth Trend ◽  
Large Power ◽  
Unit Level ◽  
Power Plant Emissions ◽  
Plant Emissions

Abstract. This paper, which focuses on emissions from China's coal-fired power plants during 1990–2010, is the second in a series of papers that aims to develop high-resolution emission inventory for China. This is the first time that emissions from China's coal-fired power plants were estimated at unit level for a 20 year period. This inventory is constructed from a unit-based database compiled in this study, named the China coal-fired Power plant Emissions Database (CPED), which includes detailed information on the technologies, activity data, operation situation, emission factors, and locations of individual units and supplements with aggregated data where unit-based information is not available. Between 1990 and 2010, compared to a 479 % growth in coal consumption, emissions from China's coal-fired power plants increased by 56, 335 and 442 % for SO2, NOx and CO2, respectively, and decreased by 23 % for PM2.5. Driven by the accelerated economy growth, large power plants were constructed throughout the country after 2000, resulting in dramatic growth in emissions. Growth trend of emissions has been effective curbed since 2005 due to strengthened emission control measures including the installation of flue-gas desulfurization (FGD) systems and the optimization of the generation fleet mix by promoting large units and decommissioning small ones. Compared to previous emission inventories, CPED significantly improved the spatial resolution and temporal profile of power plant emission inventory in China by extensive use of underlying data at unit level. The new inventory developed in this study will enable a close examination for temporal and spatial variations of power plant emissions in China and will help to improve the performances of chemical transport models by providing more accurate emission data.

scholarly journals Growth in NO<sub>x</sub> emissions from power plants in China: bottom-up estimates and satellite observations

2012 ◽  
Vol 12 (1) ◽  
pp. 45-91 ◽  
Author(s):  
S. W. Wang ◽  
Q. Zhang ◽  
D. G. Streets ◽  
K. B. He ◽  
R. V. Martin ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Emission Inventory ◽  
Transport Model ◽  
Nox Emission ◽  
Nox Emissions ◽  
Large Power ◽  
Power Plant Emissions ◽  
Tropospheric No2 ◽  
Plant Emissions

Abstract. Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.

scholarly journals Estimating CO2 Emissions from Large Scale Coal-Fired Power Plants Using OCO-2 Observations and Emission Inventories

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 811
Author(s):  
Yaqin Hu ◽  
Yusheng Shi
Keyword(s):  
Power Plant ◽  
Co2 Emissions ◽  
Atmospheric Carbon Dioxide ◽  
Power Plants ◽  
Large Scale ◽  
Global Climate ◽  
Gaussian Model ◽  
Point Sources ◽  
Emission Inventories ◽  
Bottom Up

The concentration of atmospheric carbon dioxide (CO2) has increased rapidly worldwide, aggravating the global greenhouse effect, and coal-fired power plants are one of the biggest contributors of greenhouse gas emissions in China. However, efficient methods that can quantify CO2 emissions from individual coal-fired power plants with high accuracy are needed. In this study, we estimated the CO2 emissions of large-scale coal-fired power plants using Orbiting Carbon Observatory-2 (OCO-2) satellite data based on remote sensing inversions and bottom-up methods. First, we mapped the distribution of coal-fired power plants, displaying the total installed capacity, and identified two appropriate targets, the Waigaoqiao and Qinbei power plants in Shanghai and Henan, respectively. Then, an improved Gaussian plume model method was applied for CO2 emission estimations, with input parameters including the geographic coordinates of point sources, wind vectors from the atmospheric reanalysis of the global climate, and OCO-2 observations. The application of the Gaussian model was improved by using wind data with higher temporal and spatial resolutions, employing the physically based unit conversion method, and interpolating OCO-2 observations into different resolutions. Consequently, CO2 emissions were estimated to be 23.06 ± 2.82 (95% CI) Mt/yr using the Gaussian model and 16.28 Mt/yr using the bottom-up method for the Waigaoqiao Power Plant, and 14.58 ± 3.37 (95% CI) and 14.08 Mt/yr for the Qinbei Power Plant, respectively. These estimates were compared with three standard databases for validation: the Carbon Monitoring for Action database, the China coal-fired Power Plant Emissions Database, and the Carbon Brief database. The comparison found that previous emission inventories spanning different time frames might have overestimated the CO2 emissions of one of two Chinese power plants on the two days that the measurements were made. Our study contributes to quantifying CO2 emissions from point sources and helps in advancing satellite-based monitoring techniques of emission sources in the future; this helps in reducing errors due to human intervention in bottom-up statistical methods.

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