Temperature of coastal waters and of watercourses from ASTER images

This paper presents an algorithm to improve the spatial resolution, from 90 m to 30 m, of the thermal mapping of small bodies of water or near coasts obtained from the ASTER satellite sensor. The entire procedure is based only on ASTER images. The frst part of the work deals with the physical and mathematical basis on which the algorithm was constructed, the schema of the main steps and the methods of validation of the algorithm. In the second part two applications of the algorithm are shown, the frst on the area of the delta of the Po River (Italy), the second on the lagoon of Venice (Italy)

Mt. Etna aerosol optical thickness from MIVIS images

This work focuses on the evaluation of Aerosol Optical Thickness (AOT) in Mt. Etna volcano area starting from the analysis of MIVIS VIS images. MIVIS images and ancillary data (atmospheric profiles, photometric measurements, atmospheric infrared radiances, surface temperatures, ground reflectances, SO2 abundances) were collected during the Sicily '97 campaign. Data elaboration was performed with extensive use of 6S radiative transfer model, determining optical thickness with an inversion algorithm that uses atmospheric vertical profile, ground reflectance data and radiance measured by the first MIVIS spectrometer (channels 1-20; range 0.44-0.82 mu). Ground reflectance is the most problematic parameter for the algorithm. In order to have a low and 'uniform' surface reflectance, only pixels located at an altitude between 2000-3000 in a.s.l. were analysed. At this altitude, AOT is very low during non-eruptive periods: at Torre del Filosofo (2920 in a.s.l.) on June 16th 1997, during one MIVIS flight, AOT at 0.55 mu was 0.19. The uncertainty about ground reflectance produces significant errors on volcanic background AOT, and in some cases the error is up to 100%. The developed algorithm worked well on volcanic plume, allowing us to determine the plume related pixels' AOT. High plume AOT values minimize the problems deriving from reflectance uncertainty. Plume optical thickness shows values included in a range from 0.5 to 1.0. The plume AOT map of Mt. Etna volcano, derived from a MIVIS image of June 16th 1997, is presented

Description and validation of Vehicular Emissions from Road Traffic (VERT) 1.0, an R-based framework for estimating road transport emissions from traffic flows

VERT (Vehicular Emissions from Road Traffic) is an R package developed to estimate traffic emissions of a wide range of pollutants and greenhouse gases based on traffic estimates and vehicle fleet composition data, following the EMEP/EEA methodology. Compared to other tools available in the literature, VERT is characterised by its ease of use and rapid configuration, while it maintains great flexibility in user input. It is capable of estimating exhaust, non-exhaust, resuspension, and evaporative emissions and is designed to accommodate future updates of available emission factors. In this paper, case studies conducted at both urban and regional scales demonstrate VERT's ability to accurately assess transport emissions. In an urban setting, VERT is integrated with the Lagrangian dispersion model GRAMM–GRAL and provides NOx concentrations in line with observed trends at monitoring stations, especially near traffic hotspots. On a regional scale, VERT simulations provide emission estimates that are highly consistent with the reference inventories for the Emilia-Romagna region (Italy). These findings make VERT a valuable tool for air quality management and traffic emission scenario assessment

Mt. Etna aerosol optical thickness from MIVIS images

This work focuses on the evaluation of Aerosol Optical Thickness (AOT) in Mt. Etna volcano area starting from the analysis of MIVIS VIS images. MIVIS images and ancillary data (atmospheric profiles, photometric measurements, atmospheric infrared radiances, surface temperatures, ground reflectances, SO2 abundances) were collected during the «Sicily '97» campaign. Data elaboration was performed with extensive use of 6S radiative transfer model, determining optical thickness with an inversion algorithm that uses atmospheric vertical profile, ground reflectance data and radiance measured by the first MIVIS spectrometer (channels 1-20; range 0.44-0.82 n). Ground reflectance is the most problematic parameter for the algorithm. In order to have a low and 'uniform' surface reflectance, only pixels located at an altitude between 2000-3000 m a.s.l. were analysed. At this altitude,AOT is very low during non-eruptive periods: at Torre del Filosofo (2920 m a.s.l.) on June 16th 1997, during one MIVIS flight, AOT at 0.55 n was 0.19. The uncertainty about ground reflectance produces significant errors on volcanic background AOT, and in some cases the error is up to 100%. The developed algorithm worked well on volcanic plume, allowing us to determine the plume related pixels'AOT. High plume AOT values minimize the problems deriving from reflectance uncertainty. Plume optical thickness shows values included in a range from 0.5 to 1.0. The plume AOT map of Mt. Etna volcano, derived from a MIVIS image of June 16th 1997, is presented

Spectral emissivity and temperature maps of the Solfatara crater from DAIS hyperspectral images

Quantitative maps of surface temperature and spectral emissivity have been retrieved on the Solfatara crater at Pozzuoli (Naples) from remote sensing hyperspectral data. The present study relies on thermal infrared images collected on July 27, 1997 by the DAIS hyperspectral sensor owned by the German aerospace center (DLR). The Emissivity Spectrum Normalization method was used to make temperature and emissivity estimates. Raw data were previously transformed in radiance and corrected for the atmospheric contributions using the MODTRAN radiative transfer code and the sensor response functions. During the DAIS flight a radiosonde was launched to collect the atmospheric profiles of pressure, temperature and humidity used as input to the code. Retrieved temperature values are in good agreement with temperature measurements performed in situ during the campaign. The spectral emissivity map was used to classify the image in different geo-mineralogical units with the Spectral Angle Mapper method. Areas of geologic interest were previously selected using a mask obtained from an NDVI image calculated with two channels of the visible (red) and the near infrared respectively

Micro–scale simulation of atmospheric emissions from power–plant stacks in the Po Valley

The atmospheric dispersion of the NOX plume that will be emitted from a new power–plant, at present under installation, was simulated at micro–scale with Micro–Swift–Spray (MSS) Model. The plant will be constructed in a residential urban area in the town of Modena (Po Valley, Northern Italy), where low wind speeds and thermal inversions are quite frequent. Simulation results point out a different behavior of urban canopy in influencing the 3D dispersion patterns among urban obstacles, according to atmospheric mixing conditions: in case of moderate wind events, urban canyon phenomena may occur with a consequent increasing of NOX concentration gradients among buildings, while with low winds the near–field influence of the buildings emphasizes pollutant accumulation. The MSS simulated NOX concentrations result always much lower than the regulatory limits for air quality. The comparison of simulation results with measured concentration data for NOX shows the importance of micro–scale dispersion modeling to perform an accurate and reliable assessment of meteorological condition effects on pollutant distribution, and the ability of MSS in providing reliable simulations of atmospheric dispersion

Measurement report: Source attribution and estimation of black carbon levels in an urban hotspot of the central Po Valley – an integrated approach combining high-resolution dispersion modelling and micro-aethalometers

Understanding black carbon (BC) levels and its sources in urban environments is of paramount importance due to the far-reaching health, climate, and air quality implications. While several recent studies have assessed BC concentrations at specific fixed urban locations, there is a notable lack of knowledge in the existing literature on spatially resolved data alongside source estimation methods. This study aims to fill this gap by conducting a comprehensive investigation of BC levels and sources in Modena (Po Valley, Italy), which serves as a representative example of a medium-sized urban area in Europe. Using a combination of multi-wavelength micro-aethalometer measurements and a hybrid Eulerian-Lagrangian modelling system, we studied two consecutive winter seasons (February-March 2020 and December 2020-January 2021). Leveraging the multi-wavelength absorption analyser (MWAA) model, we differentiate sources (fossil fuel combustion, FF, and biomass burning, BB) and components (BC vs. brown carbon, BrC) from micro-aethalometer measurements. The analysis reveals consistent, minimal diurnal variability in BrC absorption, in contrast to FF-related sources that exhibit distinctive diurnal peaks during rush hours, while BB sources show less diurnal variation. The city itself contributes significantly to BC concentrations (52 +/- 16 %), with BB and FF playing a prominent role (35 +/- 15 % and 9 +/- 4 %, respectively). Long-distance transport also influences BC concentrations, especially in the case of BB and FF emissions, with 28 +/- 1 % and 15 +/- 2 %, respectively. When analysing the traffic-related concentrations, Euro 4 diesel passenger cars considerably contribute to the exhaust emissions. These results provide valuable insights for policy makers and urban planners to manage BC levels in medium-sized urban areas, taking into account local and long-distance sources

Measurement report: Source attribution and estimation of black carbon levels in an urban hotspot of the central Po Valley: An integrated approach combining high-resolution dispersion modelling and micro-aethalometers

Understanding black carbon (BC) levels and their sources in urban environments is of paramount importance due to their far-reaching health, climate and air quality implications. While several recent studies have assessed BC concentrations at specific fixed urban locations, there is a notable lack of knowledge in the existing literature on spatially resolved data alongside source estimation methods. This study aims to fill this gap by conducting a comprehensive investigation of BC levels and sources in Modena (Po Valley, Italy), which serves as a representative example of a medium-sized urban area in Europe. Using a combination of multi-wavelength micro-aethalometer measurements and a hybrid Eulerian-Lagrangian modelling system, we studied two consecutive winter seasons (February–March 2020 and December 2020–January 2021). Leveraging the multi-wavelength absorption analyser (MWAA) model, we differentiate sources (fossil fuel combustion, FF, and biomass burning, BB) and components (BC vs. brown carbon, BrC) from micro-aethalometer measurements. The analysis reveals consistent, minimal diurnal variability in BrC absorption, in contrast to FF-related sources, which exhibit distinctive diurnal peaks during rush hours, while BB sources show less diurnal variation. The city itself contributes significantly to BC concentrations (52 % ± 10 %), with BB and FF playing a prominent role (35 % ± 15 % and 9 % ± 4 %, respectively). Long-distance transport also influences BC concentrations, especially in the case of BB and FF emissions, with 28 % ± 1 % and 15 % ± 2 %, respectively. When analysing the traffic related concentrations, Euro 4 diesel passenger cars considerably contribute to the exhaust emissions. These results provide valuable insights for policy makers and urban planners to manage BC levels in medium-sized urban areas, taking into account local and long-distance sources

Association between outdoor traffic air pollutants and spread of SARS-CoV-2 pandemic in Modena, Northern Italy

BACKGROUND AND AIM: Italy was the first European country severely affected by the SARS-CoV-2 pandemic, especially during the first wave in the North of the country. In particular, Modena is a city of Emilia-Romagna which is a region entirely included in the Po valley, one of European areas characterized by the heaviest air pollution levels due also to its orography. Previous studies yielded at a regional level suggested that higher air pollutant levels may increase both SARS-CoV-2 infection and mortality. METHODS: In this study, we further investigated the association between air pollutant exposure and spread of the SARS-CoV-2 using data collected from Modena municipality in the period February 2020-April 2021. We used traffic pollutant levels collected from an urban air quality monitoring station in the period January 2020-January 2021, including particulate matter (PM10), nitrogen oxides (NO2 and NOx), benzene, and black carbon (BC). We used a random-effects linear regression model within panel data analysis over the study period and we computed beta correlation coefficients (beta) with 95% confidence interval-CI between mean daily pollutant concentrations and SARS-CoV-2 daily positive cases diagnosed in Modena. RESULTS:We found a positive correlation between all traffic pollutants and SARS-CoV-2 cases, namely for PM10 beta was 1.23 (95%CI 1.00-1.46), lower for NOx (beta=0.66, 95%CI 0.56-0.75), and higher for NO2 (beta=1.95, 95%CI 1.59-2.31), benzene (beta=41.41, 95%CI 36.23-46.59), and BC (beta=5.95, 95%CI 1.19-10.72). CONCLUSIONS:Notwithstanding the limitations of use of aggregated data and potential the residual confounding, these findings seem to support the hypothesis that high levels of air pollution may favor the spread of SARS-CoV-2 infection, or alternatively that they reflect a higher mobility and number of social contacts that favor the spread of the infection. KEYWORDS: Air pollution, Traffic-related, Infectious diseases, Environmental epidemiology, Exposure assessmen