Quantification of Nitrogen Dioxide and Sulfur Dioxide emissions from Bucharest using a mobile-DOAS setup

2020 ◽  
Author(s):  
Sebastian Iancu
Keyword(s):  
Sulfur Dioxide ◽  
Nitrogen Dioxide ◽  
Human Life ◽  
Scattered Light ◽  
Fine Tuning ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Vertical Column ◽  
Airborne Measurements ◽  
The City

<p>Atmospheric pollution has a well-known impact on the human life, thus observing the emissions of trace gases is an important part of monitoring the atmospheric composition. This paper aims to determine the vertical column densities (VCDs) of Nitrogen Dioxide (NO<sub>2</sub>) and Sulfur Dioxide (SO<sub>2</sub>). These quantities will be used to calculate emissions of these pollutants quantified using a ground based mobile remote sensing technique that relies on scattered light DOAS (Differential Optical Absorption Spectroscopy) measurements. This method will be implemented using the SWING (Small Whiskbroom Imager for atmospheric compositioN monitorinG). The instrument is designed to perform airborne measurements, but for the purpose of this paper it was adapted for ground-based use by the National Institute for Aerospace Research (INCAS) in Bucharest, Romania. The source aimed to be quantified is the city of Bucharest, specifically the total emissions generated by the traffic and industry within the city. The measurements will be performed during the Spring of 2020 between February and April. The experimental setup consists of the SWING that will be mounted on the roof of a car, which allows to perform measurements along the ring road of Bucharest. There will be presented results from several days of measurements from a total of 150 hours of driving in terms of differential slant column densities (DSCDs), vertical column densities (VCDs) and quantified emissions of NO­<sub>2</sub> and SO<sub>2</sub>. This study will also be used for the fine tuning of the SWING operational parameters for use on UAV platforms in future measurement campaigns.</p>

scholarly journals Tropospheric nitrogen dioxide column retrieval from ground-based zenith–sky DOAS observations

2015 ◽  
Vol 8 (6) ◽  
pp. 2417-2435 ◽  
Author(s):  
F. Tack ◽  
F. Hendrick ◽  
F. Goutail ◽  
C. Fayt ◽  
A. Merlaud ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Measuring Instruments ◽  
Reference Spectrum ◽  
Vertical Column ◽  
Data Set ◽  
Residual Amount

Abstract. We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith–sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the differential optical absorption spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS data set acquired with a multi-axis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from 10 June to 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In the case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different data sets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2-year data set, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).

scholarly journals Validation of Aura-OMI QA4ECV NO<sub>2</sub> climate data records with ground-based DOAS networks: the role of measurement and comparison uncertainties

2020 ◽  
Vol 20 (13) ◽  
pp. 8017-8045 ◽  
Author(s):  
Steven Compernolle ◽  
Tijl Verhoelst ◽  
Gaia Pinardi ◽  
José Granville ◽  
Daan Hubert ◽  
...  
Keyword(s):  
Scattered Light ◽  
A Priori ◽  
Sampling Bias ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Climate Data ◽  
Ozone Monitoring Instrument ◽  
Vertical Column ◽  
Standard Data ◽  
The Difference

Abstract. The QA4ECV (Quality Assurance for Essential Climate Variables) version 1.1 stratospheric and tropospheric NO2 vertical column density (VCD) climate data records (CDRs) from the OMI (Ozone Monitoring Instrument) satellite sensor are validated using NDACC (Network for the Detection of Atmospheric Composition Change) zenith-scattered light differential optical absorption spectroscopy (ZSL-DOAS) and multi-axis DOAS (MAX-DOAS) data as a reference. The QA4ECV OMI stratospheric VCDs have a small bias of ∼0.2 Pmolec.cm-2 (5 %–10 %) and a dispersion of 0.2 to 1 Pmolec.cm-2 with respect to the ZSL-DOAS measurements. QA4ECV tropospheric VCD observations from OMI are restricted to near-cloud-free scenes, leading to a negative sampling bias (with respect to the unrestricted scene ensemble) of a few peta molecules per square centimetre (Pmolec.cm-2) up to −10 Pmolec.cm-2 (−40 %) in one extreme high-pollution case. The QA4ECV OMI tropospheric VCD has a negative bias with respect to the MAX-DOAS data (−1 to −4 Pmolec.cm-2), which is a feature also found for the OMI OMNO2 standard data product. The tropospheric VCD discrepancies between satellite measurements and ground-based data greatly exceed the combined measurement uncertainties. Depending on the site, part of the discrepancy can be attributed to a combination of comparison errors (notably horizontal smoothing difference error), measurement/retrieval errors related to clouds and aerosols, and the difference in vertical smoothing and a priori profile assumptions.

scholarly journals Tropospheric nitrogen dioxide column retrieval from ground-based zenith-sky DOAS observations

2015 ◽  
Vol 8 (1) ◽  
pp. 935-985
Author(s):  
F. Tack ◽  
F. Hendrick ◽  
F. Goutail ◽  
C. Fayt ◽  
A. Merlaud ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Correlation Coefficients ◽  
Atmospheric Composition ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Measuring Instruments ◽  
Reference Spectrum ◽  
Vertical Column ◽  
Residual Amount

Abstract. We present an algorithm for retrieving tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs) from ground-based zenith-sky (ZS) measurements of scattered sunlight. The method is based on a four-step approach consisting of (1) the Differential Optical Absorption Spectroscopy (DOAS) analysis of ZS radiance spectra using a fixed reference spectrum corresponding to low NO2 absorption, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total measured slant column based on stratospheric VCDs measured at sunrise and sunset, and simulation of the rapid NO2 diurnal variation, (4) the retrieval of tropospheric VCDs by dividing the resulting tropospheric slant columns by appropriate air mass factors (AMFs). These steps are fully characterized and recommendations are given for each of them. The retrieval algorithm is applied on a ZS dataset acquired with a Multi-AXis (MAX-) DOAS instrument during the Cabauw (51.97° N, 4.93° E, sea level) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI) held from the 10 June to the 21 July 2009 in the Netherlands. A median value of 7.9 × 1015 molec cm−2 is found for the retrieved tropospheric NO2 VCDs, with maxima up to 6.0 × 1016 molec cm−2. The error budget assessment indicates that the overall error σTVCD on the column values is less than 28%. In case of low tropospheric contribution, σTVCD is estimated to be around 39% and is dominated by uncertainties in the determination of the residual amount in the reference spectrum. For strong tropospheric pollution events, σTVCD drops to approximately 22% with the largest uncertainties on the determination of the stratospheric NO2 abundance and tropospheric AMFs. The tropospheric VCD amounts derived from ZS observations are compared to VCDs retrieved from off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data from a co-located Système d'Analyse par Observations Zénithales (SAOZ) spectrometer. The retrieved tropospheric VCDs are in good agreement with the different datasets with correlation coefficients and slopes close to or larger than 0.9. The potential of the presented ZS retrieval algorithm is further demonstrated by its successful application on a 2 year dataset, acquired at the NDACC (Network for the Detection of Atmospheric Composition Change) station Observatoire de Haute Provence (OHP; Southern France).

scholarly journals Sulfur dioxide retrievals from TROPOMI onboard Sentinel-5 Precursor: algorithm theoretical basis

2017 ◽  
Vol 10 (1) ◽  
pp. 119-153 ◽  
Author(s):  
Nicolas Theys ◽  
Isabelle De Smedt ◽  
Huan Yu ◽  
Thomas Danckaert ◽  
Jeroen van Gent ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Theoretical Basis ◽  
Large Range ◽  
A Priori ◽  
Optical Absorption Spectroscopy ◽  
Retrieval Algorithm ◽  
Pixel Size ◽  
Vertical Column ◽  
Spectral Fitting ◽  
Correction Scheme

Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Copernicus Sentinel-5 Precursor (S-5P) platform will measure ultraviolet earthshine radiances at high spectral and improved spatial resolution (pixel size of 7 km  ×  3.5 km at nadir) compared to its predecessors OMI and GOME-2. This paper presents the sulfur dioxide (SO2) vertical column retrieval algorithm implemented in the S-5P operational processor UPAS (Universal Processor for UV/VIS Atmospheric Spectrometers) and comprehensively describes its various retrieval steps. The spectral fitting is performed using the differential optical absorption spectroscopy (DOAS) method including multiple fitting windows to cope with the large range of atmospheric SO2 columns encountered. It is followed by a slant column background correction scheme to reduce possible biases or across-track-dependent artifacts in the data. The SO2 vertical columns are obtained by applying air mass factors (AMFs) calculated for a set of representative a priori profiles and accounting for various parameters influencing the retrieval sensitivity to SO2. Finally, the algorithm includes an error analysis module which is fully described here. We also discuss verification results (as part of the algorithm development) and future validation needs of the TROPOMI SO2 algorithm.

scholarly journals Intercomparison of four airborne imaging DOAS systems for tropospheric NO<sub>2</sub> mapping – the AROMAPEX campaign

2019 ◽  
Vol 12 (1) ◽  
pp. 211-236 ◽  
Author(s):  
Frederik Tack ◽  
Alexis Merlaud ◽  
Andreas C. Meier ◽  
Tim Vlemmix ◽  
Thomas Ruhtz ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Wavelength Region ◽  
Correlation Coefficients ◽  
Horizontal Distribution ◽  
Primary Objective ◽  
Optical Absorption Spectroscopy ◽  
Data Sets ◽  
Vertical Column ◽  
Airborne Imaging ◽  
The City

Abstract. We present an intercomparison study of four airborne imaging DOAS instruments, dedicated to the retrieval and high-resolution mapping of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs). The AROMAPEX campaign took place in Berlin, Germany, in April 2016 with the primary objective to test and intercompare the performance of experimental airborne imagers. The imaging DOAS instruments were operated simultaneously from two manned aircraft, performing synchronised flights: APEX (VITO–BIRA-IASB) was operated from DLR's DO-228 D-CFFU aircraft at 6.2 km in altitude, while AirMAP (IUP-Bremen), SWING (BIRA-IASB), and SBI (TNO–TU Delft–KNMI) were operated from the FUB Cessna 207T D-EAFU at 3.1 km. Two synchronised flights took place on 21 April 2016. NO2 slant columns were retrieved by applying differential optical absorption spectroscopy (DOAS) in the visible wavelength region and converted to VCDs by the computation of appropriate air mass factors (AMFs). Finally, the NO2 VCDs were georeferenced and mapped at high spatial resolution. For the sake of harmonising the different data sets, efforts were made to agree on a common set of parameter settings, AMF look-up table, and gridding algorithm. The NO2 horizontal distribution, observed by the different DOAS imagers, shows very similar spatial patterns. The NO2 field is dominated by two large plumes related to industrial compounds, crossing the city from west to east. The major highways A100 and A113 are also identified as line sources of NO2. Retrieved NO2 VCDs range between 1×1015 molec cm−2 upwind of the city and 20×1015 molec cm−2 in the dominant plume, with a mean of 7.3±1.8×1015 molec cm−2 for the morning flight and between 1 and 23×1015 molec cm−2 with a mean of 6.0±1.4×1015 molec cm−2 for the afternoon flight. The mean NO2 VCD retrieval errors are in the range of 22 % to 36 % for all sensors. The four data sets are in good agreement with Pearson correlation coefficients better than 0.9, while the linear regression analyses show slopes close to unity and generally small intercepts.

scholarly journals High-resolution airborne imaging DOAS measurements of NO<sub>2</sub> above Bucharest during AROMAT

2017 ◽  
Vol 10 (5) ◽  
pp. 1831-1857 ◽  
Author(s):  
Andreas Carlos Meier ◽  
Anja Schönhardt ◽  
Tim Bösch ◽  
Andreas Richter ◽  
André Seyler ◽  
...  
Keyword(s):  
Surface Properties ◽  
Urban Areas ◽  
Strong Dependence ◽  
Horizontal Distribution ◽  
Optical Absorption Spectroscopy ◽  
Surface Reflectance ◽  
Emission Rates ◽  
Vertical Column ◽  
Airborne Imaging ◽  
The City

Abstract. In this study we report on airborne imaging DOAS measurements of NO2 from two flights performed in Bucharest during the AROMAT campaign (Airborne ROmanian Measurements of Aerosols and Trace gases) in September 2014. These measurements were performed with the Airborne imaging Differential Optical Absorption Spectroscopy (DOAS) instrument for Measurements of Atmospheric Pollution (AirMAP) and provide nearly gapless maps of column densities of NO2 below the aircraft with a high spatial resolution of better than 100 m. The air mass factors, which are needed to convert the measured differential slant column densities (dSCDs) to vertical column densities (VCDs), have a strong dependence on the surface reflectance, which has to be accounted for in the retrieval. This is especially important for measurements above urban areas, where the surface properties vary strongly. As the instrument is not radiometrically calibrated, we have developed a method to derive the surface reflectance from intensities measured by AirMAP. This method is based on radiative transfer calculation with SCIATRAN and a reference area for which the surface reflectance is known. While surface properties are clearly apparent in the NO2 dSCD results, this effect is successfully corrected for in the VCD results. Furthermore, we investigate the influence of aerosols on the retrieval for a variety of aerosol profiles that were measured in the context of the AROMAT campaigns. The results of two research flights are presented, which reveal distinct horizontal distribution patterns and strong spatial gradients of NO2 across the city. Pollution levels range from background values in the outskirts located upwind of the city to about 4  ×  1016 molec cm−2 in the polluted city center. Validation against two co-located mobile car-DOAS measurements yields good agreement between the datasets, with correlation coefficients of R =  0.94 and R =  0.85, respectively. Estimations on the NOx emission rate of Bucharest for the two flights yield emission rates of 15.1 ± 9.4 and 13.6 ± 8.4 mol s−1, respectively.

Estimation of NOx, SO2 and HCHO emissions from the megacity of Lahore, Pakistan using car MAX-DOAS observations and comparison with regional model and TROPOMI satellite data

2020 ◽  
Author(s):  
Maria Razi ◽  
Steffen Dörner ◽  
Vinod Kumar ◽  
Sebastian Donner ◽  
Noor Ahmad ◽  
...  
Keyword(s):  
Emission Inventory ◽  
Regional Model ◽  
Atmospheric Pollutants ◽  
Optical Absorption Spectroscopy ◽  
Vertical Column ◽  
Strong Emission ◽  
Geometric Approximation ◽  
Vertical Column Density ◽  
The City ◽  
Measurement Campaigns

&lt;p&gt;Lahore, megacity of Pakistan with more than 11 million inhabitants is a strong emission source of atmospheric pollutants. We present results of a top-down emission procedure for NOx and SO&lt;sub&gt;2&lt;/sub&gt; for Lahore, based on car multi-axis differential optical absorption spectroscopy (car-MAX-DOAS) observations. Additionally, the total flux of HCHO from the city is determined which can be seen as an indicator for VOC emissions. Results from two extensive campaigns, which took place in summer 2017 and spring 2018 will be presented. From the measured spectra, we retrieve the vertically integrated concentration (the so-called tropospheric vertical column density, VCD) of the trace gases along the driving route by using the so-called geometric approximation method. By combining these observations with ECMWF Re-Analysis wind data, the total fluxes of NO&lt;sub&gt;x&lt;/sub&gt;, SO&lt;sub&gt;2&lt;/sub&gt; and HCHO from the city of Lahore are estimated. From both measurement campaigns, we also analyzed the seasonal variability of the above-mentioned species.&lt;/p&gt;&lt;p&gt;Derived NOx and SO&lt;sub&gt;2&lt;/sub&gt; emissions are compared to the bottom-up emission inventory EDGAR. Spatial disributions of the tropospheric NO&lt;sub&gt;2&lt;/sub&gt; and SO&lt;sub&gt;2&lt;/sub&gt; VCDs observed by car MAX-DOAS are compared with those simulated using a coupled regional-global model system (MECO(n)). We find that, the model is able to account for the spatial variablity but the VCDs are systematically underestimated by the regional model. Finally, derived NOx emissions are also compared to the emissions estimated from TROPOMI satellite observations.&lt;/p&gt;

scholarly journals Detection of pollution transport events southeast of Mexico City using ground-based visible spectroscopy measurements of nitrogen dioxide

2009 ◽  
Vol 9 (14) ◽  
pp. 4827-4840 ◽  
Author(s):  
M. L. Melamed ◽  
R. Basaldud ◽  
R. Steinbrecher ◽  
S. Emeis ◽  
L. G. Ruíz-Suárez ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Mexico City ◽  
Optical Absorption Spectroscopy ◽  
Pollution Transport ◽  
Vertical Column ◽  
Data Set ◽  
Field Campaign ◽  
Research Site ◽  
Depth Analysis ◽  
Pollution Plumes

Abstract. This work presents ground based differential optical absorption spectroscopy (DOAS) measurements of nitrogen dioxide (NO2) during the MILAGRO field campaign in March 2006 at the Tenango del Aire research site located to the southeast of Mexico City. The DOAS NO2 column density measurements are used in conjunction with ceilometer, meteorological and surface nitric oxide (NO), nitrogen oxides (NOx) and total reactive nitrogen (NOy) measurements to analyze pollution transport events to the southeast of Mexico City during the MILARGO field campaign. The study divides the data set into three case study pollution transport events that occurred at the Tenango del Aire research site. The unique data set is then used to provide an in depth analysis of example days of each of the pollution transport events. An in depth analysis of 13 March 2006, a Case One day, shows the transport of several air pollution plumes during the morning through the Tenango del Aire research site when southerly winds are present and demonstrates how DOAS tropospheric NO2 vertical column densities (VCD), surface NO2 mixing ratios and ceilometer data are used to determine the vertical homogeneity of the pollution layer. The analysis of 18 March 2006, a Case Two day, shows that when northerly winds are present for the entire day, the air at the Tenango del Aire research site is relatively clean and no major pollution plumes are detected. Case 3 days are characterized by relatively clean air throughout the morning with large DOAS NO2 enhancements detected in the afternoon. The analysis of 28 March 2006 show the DOAS NO2 enhancements are likely due to lightning activity and demonstrate how suitable ground-based DOAS measruements are for monitoring anthropogenic and natural pollution sources that reside above the mixing layer.

scholarly journals Assessment of the impact of air pollution by heat power plant emissions on the health of the population of Novokuznetsk

2019 ◽  
pp. 348-352
Author(s):  
R. A. Golikov ◽  
V. V. Kislitsyna ◽  
D. V. Surzhikov ◽  
A. M. Oleshchenko ◽  
M. A. Mukasheva
Keyword(s):  
Public Health ◽  
Air Pollution ◽  
Power Plant ◽  
Sulfur Dioxide ◽  
Nitrogen Dioxide ◽  
Hexavalent Chromium ◽  
Coal Ash ◽  
Carcinogenic Risk ◽  
The Impact ◽  
The City

Introduction. Th e study of the infl uence of air pollution on the health of the population of industrial cities is an urgent task of preventive medicine.The purpose of the study— assessment of risk for population health of the city of Novokuznetsk, associated with the receipt in atmospheric air of polluting substances from SC «Kuznetsk TPP».Materials and methods.The paper presents the results of risk assessment for the health of the population of Novokuznetsk from the impact of atmospheric emissions of coal thermal power plant. Risks were calculated in accordance with the «Guidelines for the assessment of public health risks from exposure to chemicals that pollute the environment».Results.It was found that sulfur dioxide, coal ash, nitrogen dioxide had the largest share in the index of non-carcinogenic hazard of emissions. Th e maximum hazard index of carcinogenic substances was detected in hexavalent chromium. Th e greatest risk of immediate action, manifested in the development of refl ex reactions, was detected at two points of exposure to concentrations; it was determined by the infl uence of coal ash. In the formation of the risk of chronic intoxication, coal ash, sulfur dioxide, nitrogen dioxide, nitrogen oxide had the greatest impact; the greatest risk was detected at three points. Th e hazard coeffi  cients of the concentrations ranged from 2.04×10–4 to 6.723. The maximum index of danger equal to 29.31, corresponded to the residential district of Lenin square. Th e highest levels of carcinogenic risk identifi ed at three points were determined by exposure to hexavalent chromium.Conclusion.Th e work identifi ed environmentally disadvantaged neighborhoods of the city. It is shown that the main contribution to the formation of non-carcinogenic risk of health disorders of the city’s population is made by nitric oxide and nitrogen dioxide, coal ash, sulfur dioxide. Th e main carcinogen is hexavalent chromium. Th e total values of risks expressed in the multiplicities of excess of acceptable risk, for most points exceed 1, indicating a signifi cant impact of emissions on the health of the population. A set of atmospheric protection measures aimed at reducing risks to public health is recommended. 

scholarly journals High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI)

2015 ◽  
Vol 8 (11) ◽  
pp. 4735-4754 ◽  
Author(s):  
J. P. Lawrence ◽  
J. S. Anand ◽  
J. D. Vande Hey ◽  
J. White ◽  
R. R. Leigh ◽  
...  
Keyword(s):  
Nitrogen Dioxide ◽  
Column Density ◽  
Road Traffic ◽  
City Centre ◽  
Background Concentration ◽  
Atmospheric Nitrogen ◽  
Vertical Column ◽  
East Midlands ◽  
Test Flight ◽  
The City

Abstract. Nitrogen dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI) remote sensing system. The ANDI system includes an imaging UV/Vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2) concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK on a cloud-free winter day in February 2013. Retrieved NO2 columns gridded to a surface resolution of 80 m × 20 m revealed hotspots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands) and a power station (Ratcliffe-on-Soar). In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hotspots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

Sign in / Sign up

Export Citation Format

Share Document