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.

Variability of nitrogen oxide lifetimes and emission fluxes estimated by Sentinel-5P observations

2020 ◽  
Author(s):  
Kezia Lange ◽  
Andreas Richter ◽  
John P. Burrows
Keyword(s):  
Nitrogen Oxide ◽  
Spatial Resolution ◽  
Wind Direction ◽  
Power Plants ◽  
Daily Basis ◽  
Air Pollutant ◽  
Wind Data ◽  
Nitrogen Oxide Emissions ◽  
Emission Fluxes ◽  
Global Coverage

<p>Satellite observations of the high-resolution instrument TROPOMI on Sentinel-5P make it possible to measure nitrogen dioxide (NO<sub>2</sub>) at city level and even to quantify the variability of NO<sub>x</sub> emissions and lifetimes on a seasonal and daily basis.<br>NO<sub>2</sub> is an air pollutant and especially in cities of particular importance due to the large number and strength of emission sources in combination with people living nearby exposing their health to the polluted air. To quantify nitrogen oxide emissions and lifetimes with their variability in space and time, satellite data is especially suited as it provides daily global coverage and large number of measurements. The TROPOspheric Monitoring Instrument (TROPOMI) on Sentinel-5P, launched in October 2017, provides, thanks to its higher spatial resolution when compared to previous satellite instruments, the possibility of detailed investigations on lifetimes and emissions of air pollutants.<br>Two years of TROPOMI NO<sub>2</sub> data with a spatial resolution of up to 3.5 km x 5.5 km together with ECMWF ERA5 wind data are analyzed. The NO<sub>2 </sub>data around a source is linked to the ERA5 wind data and rotated to a uniform wind direction to get clear emission patterns. Out of these two-dimensional maps of the mean NO<sub>2</sub> distribution, one dimensional line densities are calculated by integration across wind direction. Lifetimes and emission fluxes are calculated for different NO<sub>x</sub> sources such as cities and power plants distributed over the world. They are compared among each other and to bottom-up emission inventories. Seasonal variability and weekday versus weekend effects in lifetimes and emissions are discussed.</p>

scholarly journals A Note on “Metal Distribution and Short-Time Variability in Recent Sediments from the Ganges River towards the Bay of Bengal (India)” by Bonnail et al. (2019)

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 61
Author(s):  
Mohammad Ayaz Alam
Keyword(s):  
Anthropogenic Activities ◽  
River Sediments ◽  
Time Variability ◽  
New Delhi ◽  
Ganges River ◽  
National Capital Region ◽  
National Capital ◽  
Recent Sediments ◽  
Short Time ◽  
The Ganges

A careful reading of Bonnail et al. (2019)’s work points out some issues in the description of the Ganges River, e.g., describing it in a way that gives impression to the readers unfamiliar with the Indian rivers that it flows by the national capital New Delhi, after reading “it receives inputs from highly populated cities of India, including New Delhi and …”. However, as a matter of fact, it is not the Ganges, but the Yamuna River, a tributary of the Ganges, that passes through the National Capital Region of Delhi. Moreover, authors identify the studied river as the Ganges, whereas it is one of the distributaries of the Ganges called Hooghly (anglicized version of its local name Hugli). They have referred to the seasonality of the studied river; however, the flow of the studied (Hooghly) river is controlled by a barrage on the Ganges River. Moreover, Hooghly River receives input from its own tributaries; viz., Mayurakshi and Damodar, flowing through highly mineralized and coaliferous areas of Jharkhand state of India. Bonnail et al. (2019) have attributed the contamination of the river sediments to anthropogenic activities alone, by not evaluating likely natural sources. A correction factor for the underestimated total organic carbon (TOC) content obtained using Walkley-Black method should have been applied before using TOC values for factor analysis to overcome the underestimation issue with this method. This work intends to serve as a compendium, rather than a critique, to otherwise commendable work by Bonnail et al. (2019).

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 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.

Guest is God

2019 ◽  
Author(s):  
Drew Thomases
Keyword(s):  
Everyday Life ◽  
Sacred Space ◽  
Wide Spectrum ◽  
Daily Basis ◽  
Economic Changes ◽  
Ethnographic Fieldwork ◽  
Northwestern India ◽  
Gathering Place ◽  
Short Time ◽  
The Town

This book is based on ethnographic fieldwork in Pushkar, a Hindu pilgrimage site in northwestern India whose population of 20,000 sees an influx of two million visitors each year. Since the 1970s, the town has also received considerable attention from international tourists, a group with distinctly hippie beginnings but that now includes visitors from a wide spectrum of social positions and religious affiliations. To locals, though, Pushkar is more than just a gathering place for pilgrims and tourists: it is where Brahma, the creator god, made his home; it is where pilgrims feel blessed to stay, if only for a short time; and it is where Hindus would feel lucky to be reborn, if only as an insect. In short, it is their paradise. But even paradise needs upkeep. Thus, on a daily basis the town’s locals, and especially those engaged in pilgrimage and tourism, work to make Pushkar paradise. The book explores this massive enterprise to build “heaven on earth,” paying particular attention to how the articulation of sacred space becomes entangled with economic changes brought on by globalization and tourism. As such, the author not only attends to how tourism affects everyday life in Pushkar but also to how Hindu ideas determine the nature of tourism there; the goal, then, is to show how religion and tourism can be mutually constitutive.

scholarly journals Changes in Power Plant NOx Emissions over Northwest Greece Using a Data Assimilation Technique

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 900
Author(s):  
Ioanna Skoulidou ◽  
Maria-Elissavet Koukouli ◽  
Arjo Segers ◽  
Astrid Manders ◽  
Dimitris Balis ◽  
...  
Keyword(s):  
Power Plant ◽  
Data Assimilation ◽  
Energy Production ◽  
Power Plants ◽  
Transport Model ◽  
A Priori ◽  
Filter Method ◽  
Nox Emissions ◽  
A Posteriori ◽  
Data Assimilation Technique

In this work, we investigate the ability of a data assimilation technique and space-borne observations to quantify and monitor changes in nitrogen oxides (NOx) emissions over Northwestern Greece for the summers of 2018 and 2019. In this region, four lignite-burning power plants are located. The data assimilation technique, based on the Ensemble Kalman Filter method, is employed to combine space-borne atmospheric observations from the high spatial resolution Sentinel-5 Precursor (S5P) Tropospheric Monitoring Instrument (TROPOMI) and simulations using the LOTOS-EUROS Chemical Transport model. The Copernicus Atmosphere Monitoring Service-Regional European emissions (CAMS-REG, version 4.2) inventory based on the year 2015 is used as the a priori emissions in the simulations. Surface measurements of nitrogen dioxide (NO2) from air quality stations operating in the region are compared with the model surface NO2 output using either the a priori (base run) or the a posteriori (assimilated run) NOx emissions. Relative to the a priori emissions, the assimilation suggests a strong decrease in concentrations for the station located near the largest power plant, by 80% in 2019 and by 67% in 2018. Concerning the estimated annual a posteriori NOx emissions, it was found that, for the pixels hosting the two largest power plants, the assimilated run results in emissions decreased by ~40–50% for 2018 compared to 2015, whereas a larger decrease, of ~70% for both power plants, was found for 2019, after assimilating the space-born observations. For the same power plants, the European Pollutant Release and Transfer Register (E-PRTR) reports decreased emissions in 2018 and 2019 compared to 2015 (−35% and −38% in 2018, −62% and −72% in 2019), in good agreement with the estimated emissions. We further compare the a posteriori emissions to the reported energy production of the power plants during the summer of 2018 and 2019. Mean decreases of about −35% and−63% in NOx emissions are estimated for the two larger power plants in summer of 2018 and 2019, respectively, which are supported by similar decreases in the reported energy production of the power plants (~−30% and −70%, respectively).

scholarly journals Investigating Theoretical PV Energy Generation Patterns with Their Relation to the Power Load Curve in Poland

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jakub Jurasz ◽  
Jerzy Mikulik
Keyword(s):  
Energy Consumption ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Daily Basis ◽  
Hard Coal ◽  
The European Union ◽  
Load Curve ◽  
Fuel Feed ◽  
Power Load ◽  
Gross Energy

Polish energy sector is (almost from its origin) dominated by fossil fuel feed power. This situation results from an abundance of relatively cheap coal (hard and lignite). Brown coal due to its nature is the cheapest energy source in Poland. However, hard coal which fuels 60% of polish power plants is picking up on prices and is susceptible to the coal imported from neighboring countries. Forced by the European Union (EU) regulations, Poland is struggling at achieving its goal of reaching 15% of energy consumption from renewable energy sources (RES) by 2020. Over the year 2015, RES covered 11.3% of gross energy consumption but this generation was dominated by solid biomass (over 80%). The aim of this paper was to answer the following research questions: What is the relation of irradiation values to the power load on a yearly and daily basis? and how should photovoltaics (PV) be integrated in the polish power system? Conducted analysis allowed us to state that there exists a negative correlation between power demand and irradiation values on a yearly basis, but this is likely to change in the future. Secondly, on average, daily values of irradiation tend to follow power load curve over the first hours of the day.

Technically Classified Rubber—The Non-Rubber Content and the Measurement of Cure Rate

1953 ◽  
Vol 26 (3) ◽  
pp. 655-673 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Preliminary Investigation ◽  
National Bureau ◽  
Cure Rate ◽  
Average Value ◽  
Astm Method ◽  
Viscosity Increase ◽  
Strain Testing ◽  
Time Test ◽  
Short Time ◽  
Good Agreement

Abstract The nonrubber content of typical samples of all grades of technically classified rubber has been determined. It is found that the nonrubber content increases in the order: red, yellow, and blue. The chemical analyses performed to determine the nonrubber content were as follows: per cent ash, per cent nitrogen, per cent acetone extract, and per cent fatty acid. The pH of both a slurry of the ash and the aqueous digest indicates that blue rubber is more basic in these respects than are red and yellow rubbers. The measurement of the cure rate of these samples of technically classified rubber has been carried out by means of (1) conventional stress-strain testing, (2) the present ASTM method utilizing the Mooney viscometer, (3) the National Bureau of Standards strain test, (4) a new and more quantitative approach developed by Gee and coworkers, and (5) a utilization of the Mooney viscometer to determine two of the parameters of Gee's equation which gives the time dependence of modulus. All of these methods place the rubbers in the same relative order. The use of the viscometer to determine two of the parameters of Gee's equation was prompted by the degree of correlation between the rate parameter obtained with the present ASTM method and the rate constant k calculated by Gee's methods. As a result of a preliminary investigation as to the causes of viscosity increases at curing temperatures, it was found that, within limits of experimental error, all of the viscosity increase is due to the formation of a cross-linked network, with a linear relationship existing between viscosity increase ΔVc and modulus (at 100 per cent elongation) f. The results of a comparison of the rate constants obtained by the viscometer and by Gee's method indicate that for MBT mixes at 260° F there is good agreement between the methods. Statistical analysis shows that the samples employed for this study are significantly different in their rate of cure. The variance, range, and mean of some of the parameters obtained with the viscometer over a 10-week period are also given. It is suggested that the Mooney viscometer be employed to classify natural rubber according to its cure rate. If this is done, it will be necessary to define the degree of accuracy desired. To determine accurately the cure rate, it is necessary that the viscometer be used in conjunction with a press cure for the estimation of the parameter f∞. If it is not feasible to carry out press cures, an average value for f∞ can be assumed, and then only a short time test with the viscometer is required.

A Simple Statistical Theory for Grain Growth in Materials.

1990 ◽  
Vol 209 ◽  
Author(s):  
P. Mulheran ◽  
J.H. Harding
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Statistical Theory ◽  
Stochastic Model ◽  
Grain Growth ◽  
Three Dimensional ◽  
Monte Carlo Procedure ◽  
Short Time ◽  
2D And 3D ◽  
Good Agreement

A Monte Carlo procedure has been used to study the ordering of both two and three dimensional (2d and 3d) Potts Hamiltonians, further to the work of Anderson et al. For the 3d lattice, the short time growth rate is found to be much slower than previously reported, though the simulated microstructure is in agreement with the earlier studies. We propose a new stochastic model that gives good agreement with the simulations.

scholarly journals Condition Assessment of Solar Modules by Flash Test and Electroluminescence Test

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1361
Author(s):  
István Bodnár ◽  
Dávid Matusz-Kalász ◽  
Rafael Ruben Boros ◽  
Róbert Lipták
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Solar Power ◽  
Test Results ◽  
Performance Reduction ◽  
Solar Power Plants ◽  
Operational Errors ◽  
Hungarian State ◽  
Short Time ◽  
Real State

The Hungarian society and the Hungarian state are constantly increasing their solar capacity. More and more solar power plants are being put into operation. The largest of these has a 100 MW peak capacity. Such power plants do not require constant maintenance. However, in the case of low productivity, a conditional assessment is required. The reason for production loss can also be manufacturing, installation, and operational errors. A flying drone was used for finding failures by thermographic scouting. Furthermore, electroluminescent (EL) and flash tests give a comprehensive view of the real state of the modules in a mobile laboratory. We had the opportunity to summarize these test results of more than a thousand modules operating in a solar power plant. The report on the power plant shows that a significant part of the modules became unusable in a short time. After four years, 10% of the 260 Wp modules suffered a performance reduction of more than 10%.

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