scholarly journals NO<sub><I>x</I></sub> lifetimes and emissions of hotspots in polluted background estimated by satellite observations

2015 ◽  
Vol 15 (17) ◽  
pp. 24179-24215 ◽  
Author(s):  
F. Liu ◽  
S. Beirle ◽  
Q. Zhang ◽  
S. Dörner ◽  
K. B. He ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Power Plants ◽  
Nox Emissions ◽  
Wind Fields ◽  
Mountainous Regions ◽  
Wind Speeds ◽  
The Us ◽  
Calm Wind ◽  
Global Inventory ◽  
Good Agreement

Abstract. We present a new method to quantify NOx emissions and corresponding atmospheric lifetimes from OMI NO2 observations together with ECMWF wind fields without further model input for sources located in polluted background. NO2 patterns under calm wind conditions are used as proxy for the spatial patterns of NOx emissions, and the effective atmospheric NOx lifetime is determined from the change of spatial patterns measured at larger wind speeds. Emissions are subsequently derived from the NO2 mass above background integrated around the source of interest. Lifetimes and emissions are estimated for 17 power plants and 53 cities located in non-mountainous regions across China and the US. The derived lifetimes for non-mountainous sites are 3.8 ± 1.0 h on average with ranges of 1.8 to 7.5 h. The derived NOx emissions show generally good agreement with bottom-up inventories for power plants and cities. Global inventory significantly underestimated NOx emissions in Chinese cities, most likely due to uncertainties associated with downscaling approaches.

scholarly journals NO<sub><i>x</i></sub> lifetimes and emissions of cities and power plants in polluted background estimated by satellite observations

2016 ◽  
Vol 16 (8) ◽  
pp. 5283-5298 ◽  
Author(s):  
Fei Liu ◽  
Steffen Beirle ◽  
Qiang Zhang ◽  
Steffen Dörner ◽  
Kebin He ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Power Plants ◽  
Nox Emissions ◽  
Wind Fields ◽  
Mountainous Regions ◽  
Wind Speeds ◽  
The Usa ◽  
Calm Wind ◽  
Global Inventory ◽  
Good Agreement

Abstract. We present a new method to quantify NOx emissions and corresponding atmospheric lifetimes from OMI NO2 observations together with ECMWF wind fields without further model input for sources located in a polluted background. NO2 patterns under calm wind conditions are used as proxy for the spatial patterns of NOx emissions, and the effective atmospheric NOx lifetime is determined from the change of spatial patterns measured at larger wind speeds. Emissions are subsequently derived from the NO2 mass above the background, integrated around the source of interest. Lifetimes and emissions are estimated for 17 power plants and 53 cities located in non-mountainous regions across China and the USA. The derived lifetimes for the ozone season (May–September) are 3.8 ± 1.0 h (mean ± standard deviation) with a range of 1.8 to 7.5 h. The derived NOx emissions show generally good agreement with bottom-up inventories for power plants and cities. Regional inventory shows better agreement with top-down estimates for Chinese cities compared to global inventory, most likely due to different downscaling approaches adopted in the two inventories.

scholarly journals Catalog of NO<sub>x</sub> emissions from point sources as derived from the divergence of the NO<sub>2</sub> flux for TROPOMI

2021 ◽  
Author(s):  
Steffen Beirle ◽  
Christian Borger ◽  
Steffen Dörner ◽  
Henk Eskes ◽  
Vinod Kumar ◽  
...  
Keyword(s):  
Power Plants ◽  
Indian Subcontinent ◽  
Point Sources ◽  
Nox Emissions ◽  
Wind Fields ◽  
High Background ◽  
Mountainous Regions ◽  
Automated Algorithm ◽  
Background Pollution ◽  
Highly Sensitive

Abstract. We present version 1.0 of a global catalog of NOx emissions from point sources, derived from TROPOMI measurements of tropospheric NO2 for 2018–2019. The identification of sources and quantification of emissions are based on the divergence (spatial derivative) of the mean horizontal flux, which is highly sensitive for point sources like power plant exhaust stacks. The catalog lists 451 locations which could be clearly identified as NOx point source by a fully automated algorithm, while ambiguous cases as well as area sources such as Megacities are skipped. 242 of these point sources could be automatically matched to power plants. Other NOx point sources listed in the catalog are metal smelters, cement plants, or industrial areas. The four largest localized NOx emitters are all coal combustion plants in South Africa. About 1/4 of all detected point sources are located in the Indian subcontinent and are mostly associated with power plants. The catalog is incomplete, mainly due to persisting gaps in the TROPOMI NO2 product at some coastlines, inaccurate or complex wind fields in coastal and mountainous regions, and high noise in the divergence maps for high background pollution. The derived emissions are generally too low, lacking a factor of up to 2, mainly due to a low bias of TROPOMI NO2 columns. Still, the catalog has high potential for checking and improving emission inventories, as it provides accurate and independent up-to-date information on the location of sources of NOx, and thus also CO2. The catalog of NOx emissions from point sources is freely available at https://doi.org/10.26050/WDCC/Quant_NOx_TROPOMI (Beirle et al., 2020).

scholarly journals Catalog of NO<sub><i>x</i></sub> emissions from point sources as derived from the divergence of the NO<sub>2</sub> flux for TROPOMI

2021 ◽  
Vol 13 (6) ◽  
pp. 2995-3012
Author(s):  
Steffen Beirle ◽  
Christian Borger ◽  
Steffen Dörner ◽  
Henk Eskes ◽  
Vinod Kumar ◽  
...  
Keyword(s):  
Power Plants ◽  
Indian Subcontinent ◽  
Point Sources ◽  
Nox Emissions ◽  
Wind Fields ◽  
Near Surface ◽  
High Background ◽  
Mountainous Regions ◽  
Automated Algorithm ◽  
Background Pollution

Abstract. We present version 1.0 of a global catalog of NOx emissions from point sources, derived from TROPOspheric Monitoring Instrument (TROPOMI) measurements of tropospheric NO2 for 2018–2019. The identification of sources and quantification of emissions are based on the divergence (spatial derivative) of the mean horizontal flux, which is highly sensitive for point sources like power plant exhaust stacks. The catalog lists 451 locations which could be clearly identified as NOx point sources by a fully automated algorithm, while ambiguous cases as well as area sources such as megacities are skipped. A total of 242 of these point sources could be automatically matched to power plants. Other NOx point sources listed in the catalog are metal smelters, cement plants, or industrial areas. The four largest localized NOx emitters are all coal combustion plants in South Africa. About 1/4 of all detected point sources are located in the Indian subcontinent and are mostly associated with power plants. The catalog is incomplete, mainly due to persisting gaps in the TROPOMI NO2 product at some coastlines, inaccurate or complex wind fields in coastal and mountainous regions, and high noise in the divergence maps for high background pollution. The derived emissions are generally too low, lacking a factor of about 2 up to 8 for extreme cases. This strong low bias results from combination of different effects, most of all a strong underestimation of near-surface NO2 in TROPOMI NO2 columns. Still, the catalog has high potential for checking and improving emission inventories, as it provides accurate and independent up-to-date information on the location of sources of NOx and thus also CO2. The catalog of NOx emissions from point sources is freely available at https://doi.org/10.26050/WDCC/Quant_NOx_TROPOMI (Beirle et al., 2020).

scholarly journals The effect of coal-fired power-plant SO<sub>2</sub> and NO<sub>x</sub> control technologies on aerosol nucleation in the source plumes

2012 ◽  
Vol 12 (23) ◽  
pp. 11519-11531 ◽  
Author(s):  
C. R. Lonsdale ◽  
R. G. Stevens ◽  
C. A. Brock ◽  
P. A. Makar ◽  
E. M. Knipping ◽  
...  
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Particle Formation ◽  
Particle Nucleation ◽  
Nox Emissions ◽  
Emissions Control ◽  
So2 Emissions ◽  
The Us ◽  
Order Of Magnitude ◽  
Control Technologies

Abstract. Nucleation in coal-fired power-plant plumes can greatly contribute to particle number concentrations near source regions. The changing emissions rates of SO2 and NOx due to pollution-control technologies over recent decades may have had a significant effect on aerosol formation and growth in the plumes with ultimate implications for climate and human health. We use the System for Atmospheric Modeling (SAM) large-eddy simulation model with the TwO-Moment Aerosol Sectional (TOMAS) microphysics algorithm to model the nucleation in plumes of coal-fired plants. We test a range of cases with varying emissions to simulate the implementation of emissions-control technologies between 1997 and 2010. We start by simulating the W. A. Parish power plant (near Houston, TX) during this time period, when NOx emissions were reduced by ~90% and SO2 emissions decreased by ~30%. Increases in plume OH (due to the reduced NOx) produced enhanced SO2 oxidation and an order-of-magnitude increase in particle nucleation in the plume despite the reduction in SO2 emissions. These results suggest that NOx emissions could strongly regulate particle nucleation and growth in power-plant plumes. Next, we test a range of cases with varying emissions to simulate the implementation of SO2 and NOx emissions-control technologies. Particle formation generally increases with SO2 emission, while NOx shows two different regimes: increasing particle formation with increasing NOx under low-NOx emissions and decreasing particle formation with increasing NOx under high-NOx emissions. Next, we compare model results with airborne measurements made in the W. A. Parish power-plant plume in 2000 and 2006, confirming the importance of NOx emissions on new particle formation and highlighting the substantial effect of background aerosol loadings on this process (the more polluted background of the 2006 case caused more than an order-of-magnitude reduction in particle formation in the plume compared to the cleaner test day in 2000). Finally, we calculate particle-formation statistics of 330 coal-fired power plants in the US in 1997 and 2010, and the model results show a median decrease of 19% in particle formation rates from 1997 to 2010 (whereas the W. A. Parish case study showed an increase). Thus, the US power plants, on average, show a different result than was found for the W. A. Parish plant specifically, and it shows that the strong NOx controls (90% reduction) implemented at the W. A. Parish plant (with relatively weak SO2 emissions reductions, 30%) are not representative of most power plants in the US during the past 15 yr. These results suggest that there may be important climate implications of power-plant controls due to changes in plume chemistry and microphysics, but the magnitude and sign of the aerosol changes depend greatly on the relative reductions in NOx and SO2 emissions in each plant. More extensive plume measurements for a range of emissions of SO2 and NOx and in varying background aerosol conditions are needed, however, to better quantify these effects.

scholarly journals Variability of nitrogen oxide emission fluxes and lifetimes estimated from Sentinel-5P TROPOMI observations

2021 ◽  
Author(s):  
Kezia Lange ◽  
Andreas Richter ◽  
John Philip Burrows
Keyword(s):  
Power Plants ◽  
Daily Basis ◽  
Time Variability ◽  
New Delhi ◽  
Nox Emissions ◽  
Latitudinal Dependence ◽  
Emission Fluxes ◽  
Short Time ◽  
Seasonal Dependence ◽  
Good Agreement

Abstract. Satellite observations of the high-resolution instrument TROPOMI on Sentinel-5 Precursor can be used to observe nitrogen dioxide (NO2) at city scales, to quantify short time variability of NOx emissions and lifetime on a seasonal and daily basis. In this study, two years of TROPOMI NO2 data, having a spatial resolution of 3.5 km x 5.5 km, together with ECMWF ERA5 wind data have been analyzed. NOx lifetimes and emission fluxes are calculated for 45 different NOx sources comprising cities and power plants, distributed around the world. The retrieved emissions are lower than the bottom-up emission inventories from EDGAR v5.0 but are in good agreement with other TROPOMI based estimates. Separation into seasons shows a clear seasonal dependence of emissions with in general the highest emissions during winter, except for cities in hot dessert climates, where the opposite is found. The NOx lifetime shows a systematic latitudinal dependence with an increase in lifetime from two to eight hours with latitude but only a weak seasonal dependence. For most of the 45 sources, a clear weekly pattern of emissions is found with weekend-to-week day ratios of up to 0.5, but with a high variability for the different locations. During the Covid-19 lockdown period in 2020 strong reductions in the NOx emissions were observed for New Delhi, Buenos Aires and Madrid.

scholarly journals A methodology to constrain carbon dioxide emissions from coal-fired power plants using satellite observations of co-emitted nitrogen dioxide

2020 ◽  
Vol 20 (1) ◽  
pp. 99-116 ◽  
Author(s):  
Fei Liu ◽  
Bryan N. Duncan ◽  
Nickolay A. Krotkov ◽  
Lok N. Lamsal ◽  
Steffen Beirle ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Co2 Emissions ◽  
Co2 Emission ◽  
Power Plants ◽  
Operating Conditions ◽  
Satellite Observations ◽  
Nox Emissions ◽  
Bottom Up ◽  
Monitoring Instrument ◽  
The Us

Abstract. We present a method to infer CO2 emissions from individual power plants based on satellite observations of co-emitted nitrogen dioxide (NO2), which could serve as complementary verification of bottom-up inventories or be used to supplement these inventories. We demonstrate its utility on eight large and isolated US power plants, where accurate stack emission estimates of both gases are available for comparison. In the first step of our methodology, we infer nitrogen oxides (NOx) emissions from US power plants using Ozone Monitoring Instrument (OMI) NO2 tropospheric vertical column densities (VCDs) averaged over the ozone season (May–September) and a “top-down” approach that we previously developed. Second, we determine the relationship between NOx and CO2 emissions based on the direct stack emissions measurements reported by continuous emissions monitoring system (CEMS) programs, accounting for coal quality, boiler firing technology, NOx emission control device type, and any change in operating conditions. Third, we estimate CO2 emissions for power plants using the OMI-estimated NOx emissions and the CEMS NOx∕CO2 emission ratio. We find that the CO2 emissions estimated by our satellite-based method during 2005–2017 are in reasonable agreement with the US CEMS measurements, with a relative difference of 8 %±41 % (mean ± standard deviation). The broader implication of our methodology is that it has the potential to provide an additional constraint on CO2 emissions from power plants in regions of the world without reliable emissions accounting. We explore the feasibility by comparing the derived NOx∕CO2 emission ratios for the US with those from a bottom-up emission inventory for other countries and applying our methodology to a power plant in South Africa, where the satellite-based emission estimates show reasonable consistency with other independent estimates. Though our analysis is limited to a few power plants, we expect to be able to apply our method to more US (and world) power plants when multi-year data records become available from new OMI-like sensors with improved capabilities, such as the TROPOspheric Monitoring Instrument (TROPOMI), and upcoming geostationary satellites, such as the Tropospheric Emissions: Monitoring Pollution (TEMPO) instrument.

scholarly journals Estimation of NO<sub><b>x</b></sub> emissions from Delhi using car MAX-DOAS observations and comparison with OMI satellite data

2011 ◽  
Vol 11 (7) ◽  
pp. 19179-19212 ◽  
Author(s):  
R. Shaiganfar ◽  
S. Beirle ◽  
M. Sharma ◽  
A. Chauhan ◽  
R. P. Singh ◽  
...  
Keyword(s):  
Wind Speed ◽  
Spatial Patterns ◽  
Satellite Data ◽  
Satellite Observations ◽  
Nox Emissions ◽  
Pollution Levels ◽  
Satellite Retrieval ◽  
Tropospheric No2 ◽  
High Pollution ◽  
Good Agreement

Abstract. We present the first Multi-Axis- (MAX-) DOAS observations in India performed during April 2010 and January 2011 in Delhi and nearby regions. The MAX-DOAS instrument was mounted on a car roof, which allowed us to perform measurements along individual driving routes. From car MAX-DOAS observations along closed circles around Delhi, together with information on wind speed and direction, the NOx emissions from the greater Delhi area were determined: our estimate of 3.7 × 1025 molec s−1 is found to be slightly lower than the corresponding emission estimates using the EDGAR data base and substantially smaller compared to a recent study by Gurjar et al. (2004). We have also used the MAX-DOAS observations of the tropospheric NO2 VCD for validation of simultaneous satellite observations from the OMI instrument and found a good agreement of the spatial patterns. The absolute values show a reasonably good agreement. However, OMI data tends to underestimate the tropospheric NO2 VCDs in regions with high pollution levels, and tends to overestimate the tropospheric NO2 VCDs in more clean areas. These findings indicate possible discrepancies between the true vertical NO2 profiles and the profile assumptions in the OMI satellite retrieval.

scholarly journals Response of winter fine particulate matter concentrations to emission and meteorology changes in North China

2016 ◽  
Author(s):  
Meng Gao ◽  
G. R. Carmichael ◽  
P. E. Saide ◽  
Zifeng Lu ◽  
Man Yu ◽  
...  
Keyword(s):  
Wind Speed ◽  
North China ◽  
Large Fraction ◽  
Fine Particulate Matter ◽  
Weather Research And Forecasting ◽  
Nox Emissions ◽  
Wind Fields ◽  
Wind Speeds ◽  
Haze Pollution ◽  
Long Term Trends

Abstract. The winter haze is a growing problem in North China, but the causes have not been well understood. The chemistry version of the Weather Research and Forecasting model (WRF-Chem) was applied in North China to examine how the PM2.5 concentrations change in response to changes in emissions (sulfur dioxide (SO2), black carbon (BC), organic carbon (OC), ammonia (NH3), and nitrogen oxides (NOx)), as well as meteorology (temperature, relative humidity (RH), and wind speeds) changes in winter. From 1960 to 2010, the dramatic changes in emissions lead to +260 % increases in sulfate, +320 % increases in nitrate, +300 % increases in ammonium, +160 % increases in BC and 50 % increases in OC. The responses of PM2.5 to individual emission specie indicate that the simultaneous increases in SO2, NH3 and NOx emissions dominated the increases in PM2.5 concentrations. PM2.5 is more sensitive to changes in SO2 and NH3 as compared to changes in NOx emissions. In addition, OC also accounts for a large fraction in PM2.5 changes. These results provide some implications for haze pollution control. The responses of PM2.5 concentrations to temperature increases are dominated by changes in wind fields and mixing heights. PM2.5 is not sensitive to temperature increases and RH decreases, compared to changes in wind speed and aerosol feedbacks. From 1960 to 2010, aerosol feedbacks have been significantly enhanced, due to higher aerosol loadings. The discussions in this study indicate that dramatic changes in emissions are the main cause of increasing haze events in North China, and long-term trends in atmospheric circulations maybe another important cause since PM2.5 is shown to be sensitive to wind speed and aerosol feedbacks. More studies are necessary to get a better understanding of the aerosol-circulation interactions.

scholarly journals Response of winter fine particulate matter concentrations to emission and meteorology changes in North China

2016 ◽  
Vol 16 (18) ◽  
pp. 11837-11851 ◽  
Author(s):  
Meng Gao ◽  
Gregory R. Carmichael ◽  
Pablo E. Saide ◽  
Zifeng Lu ◽  
Man Yu ◽  
...  
Keyword(s):  
Wind Speed ◽  
North China ◽  
Large Fraction ◽  
Fine Particulate Matter ◽  
Nox Emissions ◽  
Wind Fields ◽  
Wind Speeds ◽  
Haze Pollution ◽  
Long Term Trends ◽  
Response To Temperature

Abstract. The winter haze is a growing problem in North China, but the causes are not well understood. The chemistry version of the Weather Research and Forecasting model (WRF-Chem) was applied in North China to examine how PM2.5 concentrations change in response to changes in emissions (sulfur dioxide (SO2), black carbon (BC), organic carbon (OC), ammonia (NH3), and nitrogen oxides (NOx)), as well as meteorology (temperature, relative humidity (RH), and wind speeds) changes in winter. From 1960 to 2010, the dramatic changes in emissions lead to +260 % increases in sulfate, +320 % increases in nitrate, +300 % increases in ammonium, +160 % increases in BC, and +50 % increases in OC. The responses of PM2.5 to individual emission species indicate that the simultaneous increases in SO2, NH3, and NOx emissions dominated the increases in PM2.5 concentrations. PM2.5 shows more notable increases in response to changes in SO2 and NH3 as compared to increases in response to changes in NOx emissions. In addition, OC also accounts for a large fraction in PM2.5 changes. These results provide some implications for haze pollution control. The responses of PM2.5 concentrations to temperature increases are dominated by changes in wind fields and mixing heights. PM2.5 shows relatively smaller changes in response to temperature increases and RH decreases compared to changes in response to changes in wind speed and aerosol feedbacks. From 1960 to 2010, aerosol feedbacks have been significantly enhanced due to higher aerosol loadings. The discussions in this study indicate that dramatic changes in emissions are the main cause of increasing haze events in North China, and long-term trends in atmospheric circulations may be another important cause since PM2.5 is shown to be substantially affected by wind speed and aerosol feedbacks. More studies are necessary to get a better understanding of the aerosol–circulation interactions.

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