scholarly journals OMI satellite observations of decadal changes in ground-level sulfur dioxide over North America

2017 ◽  
Vol 17 (9) ◽  
pp. 5921-5929 ◽  
Author(s):  
Shailesh K. Kharol ◽  
Chris A. McLinden ◽  
Christopher E. Sioris ◽  
Mark W. Shephard ◽  
Vitali Fioletov ◽  
...  
Keyword(s):  
Air Quality ◽  
North America ◽  
Sulfur Dioxide ◽  
Power Plants ◽  
Ground Level ◽  
In Situ Measurements ◽  
Ozone Monitoring Instrument ◽  
Control Laws ◽  
The Impact

Abstract. Sulfur dioxide (SO2) has a significant impact on the environment and human health. We estimated ground-level sulfur dioxide (SO2) concentrations from the Ozone Monitoring Instrument (OMI) using SO2 profiles from the Global Environmental Multi-scale – Modelling Air quality and CHemistry (GEM-MACH) model over North America for the period of 2005–2015. OMI-derived ground-level SO2 concentrations (r = 0. 61) and trends (r = 0. 74) correlated well with coincident in situ measurements from air quality networks over North America. We found a strong decreasing trend in coincidently sampled ground-level SO2 from OMI (−81 ± 19 %) and in situ measurements (−86 ± 13 %) over the eastern US for the period of 2005–2015, which reflects the implementation of stricter pollution control laws, including flue-gas desulfurization (FGD) devices in power plants. The spatially and temporally contiguous OMI-derived ground-level SO2 concentrations can be used to assess the impact of long-term exposure to SO2 on the health of humans and the environment.

scholarly journals OMI Satellite Observations of decadal changes in Ground-Level Sulfur Dioxide over North America

2016 ◽  
Author(s):  
Shailesh K. Kharol ◽  
Chris A. McLinden ◽  
Christopher E. Sioris ◽  
Mark W. Shephard ◽  
Vitali Fioletov ◽  
...  
Keyword(s):  
Air Quality ◽  
North America ◽  
Sulfur Dioxide ◽  
Power Plants ◽  
Ground Level ◽  
In Situ Measurements ◽  
Ozone Monitoring Instrument ◽  
Control Laws ◽  
The Impact

Abstract. Sulfur dioxide (SO2) has a significant impact on the environment and human health. We estimated ground-level sulfur dioxide (SO2) concentrations from the Ozone Monitoring Instrument (OMI) using SO2 profiles from the Global Environmental Multi-scale – Modelling Air quality and CHemistry (GEM-MACH) model over North America for the period of 2005–2015. OMI-derived ground-level SO2 concentrations (r = 0.61) and trends (r = 0.74) correlated well with coincident in-situ measurements from air quality networks over North America. We found a strong decreasing trend in coincidently sampled ground-level SO2 from OMI (−81 ± 19 %) and in-situ measurements (−86 ± 13 %) over Eastern US for the period of 2005–2015, which reflects the implementation of stricter pollution control laws including flue-gas desulfurization (FGD) devices in power plants. The spatially and temporally contiguous OMI derived ground-level SO2 concentrations can be used to assess the impact of long-term exposure to SO2 on the health of humans and the environment.

Evaluating Satellite Capability in Supporting Traditional Air Quality Monitoring for the Finnish Ministry of the Environment

2021 ◽  
Author(s):  
Henrik Virta ◽  
Anu-Maija Sundström ◽  
Iolanda Ialongo ◽  
Johanna Tamminen
Keyword(s):  
Air Quality ◽  
Rural Areas ◽  
Ground Level ◽  
Quality Monitoring ◽  
Air Quality Monitoring ◽  
Ozone Monitoring Instrument ◽  
Random Measurement Error ◽  
Mining Sites ◽  
Monitoring Instrument

<p>We present the results of two projects completed for the Finnish Ministry of the Environment that assessed the capability of satellites in supporting traditional in situ air quality (AQ) measurements. These projects analysed the correlation of co-located NO<sub>2</sub> measurements from the TROPOspheric Monitoring Instrument (TROPOMI, measuring in molec./cm<sup>2</sup>) and traditional air quality stations (measuring in µg/m<sup>3</sup>) in Finland and Europe in 2018 and 2019, and used the results to estimate annual mean ground-level NO<sub>2</sub> concentrations in Finland’s 14 different AQ monitoring regions.</p><p>We find that the correlation is dependent on the location of the AQ station, with city stations having a higher correlation than rural background stations. This is expected, as the variability of NO<sub>2</sub> levels in Finnish rural areas is usually within TROPOMI’s random measurement error. We also find that the estimated annual mean regional ground level NO<sub>2</sub> concentrations compare well to the in situ measurements, as the associated uncertainties provide reliable upper estimates for ground level concentrations. These estimates were used to establish that annual NO<sub>2</sub> concentrations were below the EU limit in two AQ monitoring regions with no active ground stations.</p><p>We also analyse TROPOMI’s and the Ozone Monitoring Instrument’s (OMI) ability to study the spatial distribution of NO<sub>2</sub> over Finland using gridded maps. Oversampled TROPOMI measurements are able to distinguish relatively small sources such as roads, airports and refineries, and the difference in concentrations between weekdays and weekends. TROPOMI is also able to detect emissions from different sources of NO<sub>2</sub> such as cities, mining sites and industrial areas. Long time series measurements from OMI show decreasing NO<sub>2</sub> levels over Finland between 2005 and 2018.</p><p>The studies were conducted on behalf of the Finnish Ministry of the Environment, and showcase how satellite measurements can be used to supplement traditional air quality measurements in areas with poor ground station coverage. Launched in 2017, TROPOMI is currently the highest-resolution air quality sensing satellite, and its societal uses are only beginning to be realised. Future Sentinel missions, especially the geosynchronous Sentinel-4, will further extend satellite air quality monitoring capabilities and enable continuous daytime observations in cloud-free conditions.</p>

Satellite-based observations of ground-level fine particulate matter and comparison to a regional air quality model

2020 ◽  
Author(s):  
Jana Handschuh ◽  
Frank Baier ◽  
Thilo Erbertseder ◽  
Martijn Schaap
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Air Pollutants ◽  
Fine Particulate Matter ◽  
Ground Level ◽  
In Situ Measurements ◽  
Satellite Observations ◽  
Optical Parameters ◽  
Fine Particulate

<p>Particulate matter and other air pollutants have become an increasing burden on the environment and human health. Especially in metropolitan and high-traffic areas, air quality is often remarkably reduced. For a better understanding of the air quality in specific areas, which is of great environment-political interest, data with high resolution in space and time is required. The combination of satellite observations and chemistry-transport-modelling has proven to give a good database for assessments and analyses of air pollution. In contrast to sample in-situ measurements, satellite observations provide area-wide coverage ​​of measurements and thus the possibility for an almost gapless mapping of actual air pollutants. For a high temporal resolution, chemistry-transport-models are needed, which calculate concentrations of specific pollutants in continuous time steps. Satellite observations can thus be used to improve model performances.</p><p>There are no direct satellite-measurements of fine particulate matter (PM2.5) but ground-level concentrations of PM2.5 can be derived from optical parameters such as aerosol optical depth (AOD). A wide range of methods for the determination of PM2.5 concentrations from AOD measurements has been developed so far, but it is still a big challenge. In this study a semi-empirical approach based on the physical relationships between meteorological and optical parameters was applied to determine a first-guess of ground-level PM2.5 concentrations for the year 2018 and the larger Germany region. Therefor AOD observations of MODIS (Moderate Resolution Imaging Spectroradiometer) aboard the NASA Aqua satellite were used in a spatial resolution of 3km. First results showed an overestimation of ground-level aerosols and quiet low correlations with in-situ station measurements from the European Environmental Agency (EEA). To improve the results, correction factors were calculated using the coefficients of linear regression between satellite-based and in-situ measured particulate matter concentrations. Spatial and seasonal dependencies were taken into account with it. Correlations between satellite and in-situ measurements could be improved applying this method.</p><p>The MODIS 3km AOD product was found to be a good base for area-wide calculations of ground-level PM2.5 concentrations. First comparisons to the calculated PM2.5 concentrations from chemistry-transport-model POLYPHEMUS/DLR showed significant differences though. Satellite observations will now be used to improve the general model performance, first by helping to find and understand regional and temporal dependencies in the differences. As part of the German project S-VELD funded by the Federal Ministry of Transport and Digital Infrastructure BMVI, it will help for example to adjust the derivation of particle emissions within the model.</p>

scholarly journals Quantifying the Impacts of COVID-19 Lockdown and Spring Festival on Air Quality over Yangtze River Delta Region

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 735
Author(s):  
Zeeshan Javed ◽  
Aimon Tanvir ◽  
Yuhang Wang ◽  
Ahmed Waqas ◽  
Mingjie Xie ◽  
...  
Keyword(s):  
Air Quality ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
In Situ Measurements ◽  
River Delta ◽  
Anthropogenic Activity ◽  
Spring Festival ◽  
The Yrd ◽  
The Impact

The emergence of the novel corona virus and the resulting lockdowns over various parts of the world have substantially impacted air quality due to reduced anthropogenic activity. The objective of this study is to investigate the impact of COVID-19 lockdown and Spring Festival on air quality of four major cities of Yangtze River Delta (YRD) region, including Shanghai, Nanjing, Hefei, and Hangzhou. In situ measurements were taken for nitrogen dioxide (NO2), particulate matter (PM2.5) and ozone (O3). In situ measurements from 1 January to 25 April were taken two years prior to COVID-19 (2018–19), during COVID-19 lockdown (2020), and one year after the COVID-19 (2021). The results indicated that the concentration of NO2 and PM2.5 dropped considerably during the lockdown days compared to normal days while the O3 concentration showed an upsurge. The NO2 showed reduction of about 54% on average during lockdown level 1 in 2020 whereas, PM 2.5 showed reduction of about 36% through the YRD. A substantial drop was observed in concentration of NO2 during the Spring Festival holidays throughout the YRD from 2019 to 2021.

scholarly journals Modeling Pollutant Emissions: Influence of Two Heat and Power Plants on Urban Air Quality

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5218 ◽  
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Air Quality ◽  
Power Plants ◽  
Computer Software ◽  
Field Measurements ◽  
Ground Level ◽  
Pollutant Emissions ◽  
Hard Coal ◽  
Industrial Plants ◽  
Aerial Vehicle ◽  
The Impact

Large industrial plants, power plants, and combined heat and power plants are popularly believed to be the main sources of point emissions, affecting both local and global air quality. This is because these installations emit significant amounts of pollutants at high altitudes every year. In this study, we investigate the impact of two solid fuel (hard coal)-fired CHP plants located within the urban agglomeration on the air quality of the city of Lodz in Poland (Europe). We used an OPA03 computer software to model the spatial distribution of pollutants. The results show that the annual average concentrations of pollutants were highest at an altitude of 25 m above ground level and decreased at lower measurement heights. The concentrations did not exceed permissible levels, reaching only 4% of national and international regulatory limits. We also made field measurements during the winter heating period, using an unmanned aerial vehicle (UAV) equipped with sensors to map the distributions of dust and gas pollutants in the areas with the highest concentrations of emissions from the two heat and power plants. Overall, the field measurements confirmed that it is not high-altitude emissions that have the greatest impact on local air quality.

scholarly journals Assessing an Atmospheric Correction Algorithm for Time Series of Satellite-Based Water-Leaving Reflectance Using Match-Up Sites in Australian Coastal Waters

2021 ◽  
Vol 13 (10) ◽  
pp. 1927
Author(s):  
Fuqin Li ◽  
David Jupp ◽  
Thomas Schroeder ◽  
Stephen Sagar ◽  
Joshua Sixsmith ◽  
...  
Keyword(s):  
Coastal Waters ◽  
Atmospheric Correction ◽  
Correction Method ◽  
In Situ Measurements ◽  
Landsat 8 ◽  
Correction Algorithm ◽  
Simple Method ◽  
North East ◽  
The Impact

An atmospheric correction algorithm for medium-resolution satellite data over general water surfaces (open/coastal, estuarine and inland waters) has been assessed in Australian coastal waters. In situ measurements at four match-up sites were used with 21 Landsat 8 images acquired between 2014 and 2017. Three aerosol sources (AERONET, MODIS ocean aerosol and climatology) were used to test the impact of the selection of aerosol optical depth (AOD) and Ångström coefficient on the retrieved accuracy. The initial results showed that the satellite-derived water-leaving reflectance can have good agreement with the in situ measurements, provided that the sun glint is handled effectively. Although the AERONET aerosol data performed best, the contemporary satellite-derived aerosol information from MODIS or an aerosol climatology could also be as effective, and should be assessed with further in situ measurements. Two sun glint correction strategies were assessed for their ability to remove the glint bias. The most successful one used the average of two shortwave infrared (SWIR) bands to represent sun glint and subtracted it from each band. Using this sun glint correction method, the mean all-band error of the retrieved water-leaving reflectance at the Lucinda Jetty Coastal Observatory (LJCO) in north east Australia was close to 4% and unbiased over 14 acquisitions. A persistent bias in the other strategy was likely due to the sky radiance being non-uniform for the selected images. In regard to future options for an operational sun glint correction, the simple method may be sufficient for clear skies until a physically based method has been established.

The importance of the turbulent ship wake regime for pollutant fate and transport

2021 ◽  
Author(s):  
Amanda T. Nylund ◽  
Rickard Bensow ◽  
Mattias Liefvendahl ◽  
Arash Eslamdoost ◽  
Anders Tengberg ◽  
...  
Keyword(s):  
Fate And Transport ◽  
In Situ Measurements ◽  
Ex Situ ◽  
Landsat 8 ◽  
Turbulent Regime ◽  
Near Wake ◽  
Ship Wake ◽  
Spatiotemporal Scales ◽  
The Impact

<p>This interdisciplinary study with implications for fate and transport of pollutants from shipping, investigates the previously overlooked phenomenon of ship induced mixing. When a ship moves through water, the hull and propeller induce a long-lasting turbulent wake. Natural waters are usually stratified, and the stratification influences both the vertical and horizontal extent of the wake. The altered turbulent regime in shipping lanes governs the distribution of discharged pollutants, e.g. PAHs, metals, nutrients and non-indigenous species. The ship related pollutant load follows the trend in volumes of maritime trade, which has almost tripled since the 1980s. In heavily trafficked areas there may be one ship passage every ten minutes; today shipping constitutes a significant source of pollution.</p><p>To understand the environmental impact of shipping related pollutants, it is essential to know their fate following regional scale transport. However, previous modelling efforts assuming discharge at the surface will not adequately reflect the input values in the regional models. Therefore, it is urgent to bridge the gaps between the spatiotemporal scales from high-resolution numerical modeling of the flow hydrodynamics around the ship, mixing processes and interaction of the ship and wake with stratification, and parameterization in regional oceanographic modeling. Here this knowledge gap is addressed by combining an array of methods; in situ measurements, remote sensing and numerical flow modeling.</p><p>A bottom-mounted Acoustic Doppler Current Profiler was placed under a ship lane, for <em>in-situ</em> measurements of the vertical and temporal expansion of turbulent wakes. In addition, <em>ex-situ</em> measurements with Landsat 8 Thermal Infrared Sensor were used to estimate the longevity and spatial extent of the thermal signal from ship wakes. The computational modelling was conducted using well resolved 3D RANS modelling for the hull and the near wake (up to five ship lengths aft), a method typically used for the near wake behaviour in analysing the propulsion system. As this is not feasible to use for a far wake analysis, the predicted wake is then used as input for a 2D+time modelling for the sustained wake up to 30min after the ship passage. These results, both from measurements and numerical models, are then combined to analyse how ship-induced turbulence influence at what depth discharged pollutants will be found.</p><p>This first step to cover the mesoscales of the turbulent ship wake is necessary to assess the impact of ship related pollution. In-situ measurements show median wake depth 13.5m (max 31.5m) and median longevity 10min (max 29min). Satellite data show median thermal wake signal 13.7km (max 62.5km). A detailed simulation model will only be possible to use for the first few 100m of the ship wake, but the coupling to a simplified 2D+time modelling shows a promising potential to bridge our understanding of the impact of the ship wake on the larger scales. Our model results indicate that the natural stratification affects the distribution and retention of pollutants in the wake region. The depth of discharge and the wake turbulence characteristics will in turn affect the fate and transport of pollutants on larger spatiotemporal scales.</p>

scholarly journals Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula

2011 ◽  
Vol 11 (7) ◽  
pp. 3067-3091 ◽  
Author(s):  
C. Córdoba-Jabonero ◽  
M. Sorribas ◽  
J. L. Guerrero-Rascado ◽  
J. A. Adame ◽  
Y. Hernández ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Particle Deposition ◽  
Ground Level ◽  
In Situ Measurements ◽  
Saharan Dust ◽  
Dust Transport ◽  
Air Masses ◽  
Potential Impact

Abstract. The synergetic use of meteorological information, remote sensing both ground-based active (lidar) and passive (sun-photometry) techniques together with backtrajectory analysis and in-situ measurements is devoted to the characterization of dust intrusions. A case study of air masses advected from the Saharan region to the Canary Islands and the Iberian Peninsula, located relatively close and far away from the dust sources, respectively, was considered for this purpose. The observations were performed over three Spanish geographically strategic stations within the dust-influenced area along a common dust plume pathway monitored from 11 to 19 of March 2008. A 4-day long dust event (13–16 March) over the Santa Cruz de Tenerife Observatory (SCO), and a linked short 1-day dust episode (14 March) in the Southern Iberian Peninsula over the Atmospheric Sounding Station "El Arenosillo" (ARN) and the Granada station (GRA) were detected. Meteorological conditions favoured the dust plume transport over the area under study. Backtrajectory analysis clearly revealed the Saharan region as the source of the dust intrusion. Under the Saharan air masses influence, AERONET Aerosol Optical Depth at 500 nm (AOD500) ranged from 0.3 to 0.6 and Ångström Exponent at 440/675 nm wavelength pair (AE440/675) was lower than 0.5, indicating a high loading and predominance of coarse particles during those dusty events. Lidar observations characterized their vertical layering structure, identifying different aerosol contributions depending on altitude. In particular, the 3-km height dust layer transported from the Saharan region and observed over SCO site was later on detected at ARN and GRA stations. No significant differences were found in the lidar (extinction-to-backscatter) ratio (LR) estimation for that dust plume over all stations when a suitable aerosol scenario for lidar data retrieval is selected. Lidar-retrieved LR values of 60–70 sr were obtained during the main dust episodes. These similar LR values found in all the stations suggest that dust properties were kept nearly unchanged in the course of its medium-range transport. In addition, the potential impact on surface of that Saharan dust intrusion over the Iberian Peninsula was evaluated by means of ground-level in-situ measurements for particle deposition assessment together with backtrajectory analysis. However, no connection between those dust plumes and the particle sedimentation registered at ground level is found. Differences on particle deposition processes observed in both Southern Iberian Peninsula sites are due to the particular dust transport pattern occurred over each station. Discrepancies between columnar-integrated and ground-level in-situ measurements show a clear dependence on height of the dust particle size distribution. Then, further vertical size-resolved observations are needed for evaluation of the impact on surface of the Saharan dust arrival to the Iberian Peninsula.

Vertically detailed in situ measurements of gelbstoff: demonstrating the impact of a runoff event

Hydrobiologia ◽  
2004 ◽  
Vol 517 (1-3) ◽  
pp. 171-177
Author(s):  
Steven W. Effler ◽  
David M. O'Donnell ◽  
MaryGail Perkins ◽  
David G. Smith
Keyword(s):  
In Situ Measurements ◽  
Runoff Event ◽  
The Impact

scholarly journals Entrainment and Mixing of Transported Ozone Layers: Implications for Surface Air Quality in the Western U.S.

2020 ◽  
Vol 237 ◽  
pp. 03012
Author(s):  
Christoph Senff ◽  
Andrew Langford ◽  
Raul Alvarez ◽  
Tim Bonin ◽  
Alan Brewer ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Mixed Layer ◽  
Las Vegas ◽  
Surface Ozone ◽  
Ground Level ◽  
San Joaquin Valley ◽  
Fire Emissions ◽  
Ozone Transport ◽  
The Impact

Recently, two air quality campaigns were conducted in the southwestern United States to study the impact of transported ozone, stratospheric intrusions, and fire emissions on ground-level ozone concentrations. The California Baseline Ozone Transport Study (CABOTS) took place in May – August 2016 covering the central California coast and San Joaquin Valley, and the Fires, Asian, and Stratospheric Transport Las Vegas Ozone Study (FAST-LVOS) was conducted in the greater Las Vegas, Nevada area in May – June 2017. During these studies, nearly 1000 hours of ozone and aerosol profile data were collected with the NOAA TOPAZ lidar. A Doppler wind lidar and a radar wind profiler provided continuous observations of atmospheric turbulence, horizontal winds, and mixed layer height. These measurements allowed us to directly observe the degree to which ozone transport layers aloft were entrained into the boundary layer and to quantify the resulting impact on surface ozone levels. Mixed layer heights in the San Joaquin Valley during CABOTS were generally below 1 km above ground level (AGL), while boundary layer heights in Las Vegas during FAST-LVOS routinely exceeded 3 km AGL and occasionally reached up to 4.5 km AGL. Consequently, boundary layer entrainment was more often observed during FAST-LVOS, while most elevated ozone layers passed untapped over the San Joaquin Valley during CABOTS.

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