ABSTRACT In the last few years, several efforts have been made in order to improve the representa... more ABSTRACT In the last few years, several efforts have been made in order to improve the representation of urban surface characteristics in mesoscale models. In general, attempts have been made either to improve the `thermal' part (impact on the heat fluxes) or the `dynamical' part (impact on the wind field and the turbulent kinetic energy). The objective is to improve the quantification of the fluxes associated with heat storage change and to account more explicitly for the integrated effect of urban canopy layer fluxes on the overlaying boundary layer. This modification is very important, since pollutant dispersion is strongly dependent on the structure of the urban boundary layer and on its interactions with the rural boundary layer and the synoptic flow. In the present study, the MM5 model (Penn State/NCAR Mesoscale Model, Anthes et al., 1978) was modified, by considering recent advances in the planetary boundary layer. In particular, the modifications were carried out in two directions; a) the surface stress and fluxes of heat and momentum were parameterized for use of the MM5 model with emphasis laid on unstable conditions. The key quantities in these parameterizations are the PBL height and the convective velocity scale W*. In addition, the Kansas-type functions were modified in order to satisfy the free convection limit which is particularly important in cases with larger roughness lengths; and (b) with respect to the thermal properties of an urban surface, the surface energy balance was modified by taking into account the anthropogenic heat released in urban areas and the urban heat storage term, to account for urban/building mass effect, including hysteresis. These modifications were applied to the high resolution non-local MRF PBL parameterization scheme, based on Troen and Marht. Numerical simulations were carried out for the Greater Athens area. The modifications mentioned above, produce minor changes to the wind field, but they enhance the value of friction velocity up to 25% during strong instability over very rough surfaces and the diffusion coefficients, up to a proportion of 30%, depending on the intensity of the instability. Moreover, they enhance the temperature's diurnal range. These enhancements affect the pollutants deposition velocity and consequently the pollutants dispersion in the atmosphere.
Boundary-Layer Meteorol (2007) 124:324 DOI 10.1007/s10546-007-9170-0 ORIGINAL PAPER ... The surf... more Boundary-Layer Meteorol (2007) 124:324 DOI 10.1007/s10546-007-9170-0 ORIGINAL PAPER ... The surface energy balance and the mixing height in urban areas activities and recommendations of COST-Action 715 ... Martin Piringer · Sylvain Joffre · Alexander Baklanov · Andreas ...
... 7.5.2 Comparison between UHF profiler and RASS data .....152 7.6 THE MIXING HEIGHT DEDUCED FR... more ... 7.5.2 Comparison between UHF profiler and RASS data .....152 7.6 THE MIXING HEIGHT DEDUCED FROM ... in turn limits the dilution of the pollutants, and the urban plume may be ... As a rule-of-thumb, z* is somewhere between 2 5 hr (see ...
Journal of Wind Engineering and Industrial Aerodynamics, 1998
... Parameterization of convective and stable internal boundary layers into mass consistent model... more ... Parameterization of convective and stable internal boundary layers into mass consistent models. F. Castino * and M. Tombrou. ... E-mail: [email protected]. Journal of Wind Engineering and Industrial Aerodynamics Volumes 74-76, 1 April 1998, Pages 239-247. ...
This paper presents a new theory of the convective heat/mass transfer. It focuses on (i) advanced... more This paper presents a new theory of the convective heat/mass transfer. It focuses on (i) advanced treatment of turbulent mixing caused by large-scale semi-organised eddies overlooked in the classical theory and (ii) interactions between large eddies and surface roughness elements up to very high obstacles such as buildings, rocks and hills. Large-scale structures in the shear-free convective boundary layers consist of strong plumes and wider but weaker downdraughts. Close to the surface they cause local "convective winds" blowing towards the plume axes. The latter generate turbulence, in addition to its generation by the buoyancy forces, and strongly enhance turbulent fluxes of heat and other scalars. This mechanism is especially important over very rough surfaces. The proposed advanced model is validated against data from measurements over different sites and also through large-eddy simulation of convective boundary layers (CBLs) over a range of surfaces from very smooth to extremely rough. Excellent correspondence between model results, field observations and large-eddy simulations is achieved. The obtained resistance and heat/mass transfer laws are recommended for practical use in meso-scale, weather-prediction, climate and other environmental models.
The simulated nocturnal boundary layer height, h, from several widely used diagnostic relations a... more The simulated nocturnal boundary layer height, h, from several widely used diagnostic relations as well as from one prognostic relation, is compared with direct estimation of h, from radiosonde profiles available at 24h Z. The required input data are no more than surface wind speed, air temperature and total cloud cover. Of these, best performance is found using the relationship of Nieuwstadt [1]. It should also be mentioned that the comparison of estimations of h, against measurements improved when the observed height was determined at the maximum wind.
Results are presented from a windturbulence measurements campaign at the summit of ahill in compl... more Results are presented from a windturbulence measurements campaign at the summit of ahill in complex terrain in Andros island (Greece)where a wind turbine park has been constructed. Meanturbulence parameters and power spectra from three 30 mmasts located at the summit, upwind and downwind ofthe hill are analysed to ascertain the differencesfrom respective parameters in flat terrain and toassess the influence of the irregular topography. Thevariances of the horizontal (vertical) wind components are found tobe smaller (larger) than the onesfrom flat terrain. Of the available correlations forthe power spectra, the Von Karman one was found togive better results, although the low frequency partsshow pronounced lags. The asymmetry of the upwindterrain for different wind directions and especiallyits slope is clearly felt both by variances and byspectra. This influence, as expected, is found toincrease with increasing stability. These results havean important significance for wind turbine design andwind energy utilisation.
This study examines tropospheric ozone, its precursors and CO mixing ratios over Eu- rope during ... more This study examines tropospheric ozone, its precursors and CO mixing ratios over Eu- rope during 2001, using a modified version of the global three-dimensional chemical transport model (CTM) GEOS-CHEM. Our approach employs a methodology, identi- fied as a one-way nested grid formulation, to increase the horizontal resolution above the one adopted for the global scale. The nested grid methodology permits the treat- ment of chemistry over a particular region with relatively high horizontal resolution, while at the same time preserves the interaction of this region with the coarser global environment. The model is initially applied over the whole globe, including the nested domain. Then, the fine-resolution model is run for Europe with boundary conditions from the coarse global simulation. No feedback is applied in the coarse model. Differences between model results obtained using the nested grid and the coarse grid are discussed. Model calculations are compared to observations col- le...
modern atmosphere-hydrosphere-biosphere model chains, convective boundary-layer models and parame... more modern atmosphere-hydrosphere-biosphere model chains, convective boundary-layer models and parameterization packages represent the most important coupling agents, which essentially control the overall quality of predictions from coupled models. This paper focuses on the enhancement of turbulent mixing due to large-scale semi-organized eddies and interactions between large eddies and surface roughness elements up to very high obstacles such as buildings, rocks and hills. Large-scale structures in the shear-free convective boundary layers consist of strong plumes and wider but weaker downdraughts. Close to the surface they cause local ”convective winds“ blowing towards the plume axes. The latter generate turbulence, in addition to its generation by the buoyancy forces, and strongly contribute to the turbulent fluxes of heat and other scalars. This mechanism is especially important over very rough surfaces. The proposed model is validated against data from measurements over different sites and also through large-eddy simulation (LES) of convective boundary layers (CBLs) over a range of surfaces from very smooth to extremely rough. Excellent correspondence between model results, field observations and large-eddy simulations is achieved. The obtained resistance and heat/mass transfer laws are recommended for practical use inmeso-scale, weatherprediction, climate and other environmental models.
International Journal of Environment and Pollution, 2000
ABSTRACT This study tries to inform the user of the abilities and limitations of dispersion model... more ABSTRACT This study tries to inform the user of the abilities and limitations of dispersion models by comparing their differences in air pollution estimations. In particular, an intercomparison between the results of Eulerian and regulatory dispersion models for the new electric power plant in Rhodes Island is carried out, in order to emphasise their differences. The Eulerian models used in this study are Airpol and UAM, the latter also incorporating photochemistry. The input meteorological parameters and diffusion coefficients for both of these models are provided from the non-hydrostatic prognostic mesoscale meteorological model TVM. The regulatory models that have been used are Plumes and CTDMPLUS which are both Gaussian models and use hourly routine meteorological data as input. The simulations have been carried out for one year, and the worst results have been compared. A satisfactory agreement was found among the results for long-term predictions, while a spatial variation was observed for short-term predictions.
ABSTRACT This study analyzes air quality data provided by numerical simulations for the Greater A... more ABSTRACT This study analyzes air quality data provided by numerical simulations for the Greater Athens Area (GAA) using the latest release of the emission inventory (industry, traffic, off road activities, airport, railway, harbor). The three-dimensional photochemical Urban Airshed Model (UAM-V) was coupled with the meteorological Mesoscale Model (MM5). All the simulated days favored high concentration levels of air pollutants. The concentrations of the air pollutants produced by the simulations were compared with routine measurements from the operating stations of the existing air pollution monitor network in Athens. The comparison revealed good agreement for the stations sited in the center of Athens while the observed discrepancies in a few suburban stations could be explained by the fact that few sectors (e.g. biogenic) are not included in the Athens emission inventory. Moreover, the importance of the VOCs reactivity on photochemical modeling, especially on ozone productivity, was investigated after constructing various speciation profiles of the VOCs emissions in agreement with the different land uses (urban, semi-urban). These profiles were derived from a large number of VOC species (about 200) contained in detailed emission inventories. Furthermore, the role of biogenic emissions was examined by incorporating the rural environments. Finally, a modeling contribution to the aerosols' concentration levels in the Greater Athens Area is attempted using the three dimensional Regional Modeling System for Aerosols and Deposition (REMSAD). The aerosol distribution/deposition and toxic chemistry is examined, making use of the emissions of particulate matter included in the emission inventory such as PM, NH3 and toxics (Hg, Pb, Zn, As, Cu). Further simulations are performed by considering changes in the PM speciation. Finally, the correlation between the gaseous pollutants and the aerosol species is performed in order to provide important conclusions in areas or time-periods lacking PM measurements.
The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated ... more The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated with the mesoscale CAMx model using the individual plume segment approach, in a highly resolved domain, covering the Athens International Airport. Emission indices during take-off measured at the Athens International Airport are incorporated. Model predictions are compared with in situ point and path-averaged observations (NO, NO₂) downwind of the runway at the ground. The influence of modeling process, dispersion properties and background air composition on the chemical evolution of the aircraft plumes is examined. It is proven that the mixing properties mainly determine the plume dispersion. The initial plume properties become significant for the selection of the appropriate vertical resolution. Besides these factors, the background NOx and O₃ concentration levels control NOx distribution and their conversion to nitrogen reservoir species.
Integrated environmental management in urban areas is nowadays considered a sine qua non objectiv... more Integrated environmental management in urban areas is nowadays considered a sine qua non objective of Community and national environmental and development policies. A large amount of scientific information on the state of the environment is now available from a large pool of data sources. This work presents an innovative method for integration of these data sources and effective coupling of environmental information with appropriate models and decision-support tools. State-ofthe-art Earth observation techniques, ground-based air quality measurements, atmospheric transport and chemical modelling, and multi-criteria decision-aid systems are used in an integrated information fusion environment in support of environmental and health impact assessment and decision-making at the urban and regional scales. Results of the pilot application of the method in the area of Lombardy in Northern Italy demonstrate the validity and usefulness of this novel approach.
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003
The current state of the art in air quality assessment, monitoring and management comprises analy... more The current state of the art in air quality assessment, monitoring and management comprises analytical measurements and atmospheric transport modeling. Earth observation from satellites provides an additional information layer through the calculation of synoptic air pollution indicators, such as atmospheric turbidity. Fusion of these data sources with ancillary data, including classification of population vulnerability to the adverse health effects of particulate pollution in the ambient air integrates them into an optimally managed environmental information processing tool. The computational assessment method described in this work permits a detailed spatial characterization of the domain of interest with a view to optimizing air quality management in order to reduce the corresponding adverse health impact. Results from the pilot application of this technique for integrated environmental and health assessment in the urban environment are given.
In the present study the horizontal distribution of columnar aerosol optical thicknessderived at ... more In the present study the horizontal distribution of columnar aerosol optical thicknessderived at high spatial resolution from Earth observation satellite data in the Lombardy area (Italy) was converted to the horizontal distribution of optically effective aerosols concentration at the ground level. This was achieved by incorporating information on atmosphere's mixing height, at which pollutants released at ground level are vertically
ABSTRACT In the last few years, several efforts have been made in order to improve the representa... more ABSTRACT In the last few years, several efforts have been made in order to improve the representation of urban surface characteristics in mesoscale models. In general, attempts have been made either to improve the `thermal' part (impact on the heat fluxes) or the `dynamical' part (impact on the wind field and the turbulent kinetic energy). The objective is to improve the quantification of the fluxes associated with heat storage change and to account more explicitly for the integrated effect of urban canopy layer fluxes on the overlaying boundary layer. This modification is very important, since pollutant dispersion is strongly dependent on the structure of the urban boundary layer and on its interactions with the rural boundary layer and the synoptic flow. In the present study, the MM5 model (Penn State/NCAR Mesoscale Model, Anthes et al., 1978) was modified, by considering recent advances in the planetary boundary layer. In particular, the modifications were carried out in two directions; a) the surface stress and fluxes of heat and momentum were parameterized for use of the MM5 model with emphasis laid on unstable conditions. The key quantities in these parameterizations are the PBL height and the convective velocity scale W*. In addition, the Kansas-type functions were modified in order to satisfy the free convection limit which is particularly important in cases with larger roughness lengths; and (b) with respect to the thermal properties of an urban surface, the surface energy balance was modified by taking into account the anthropogenic heat released in urban areas and the urban heat storage term, to account for urban/building mass effect, including hysteresis. These modifications were applied to the high resolution non-local MRF PBL parameterization scheme, based on Troen and Marht. Numerical simulations were carried out for the Greater Athens area. The modifications mentioned above, produce minor changes to the wind field, but they enhance the value of friction velocity up to 25% during strong instability over very rough surfaces and the diffusion coefficients, up to a proportion of 30%, depending on the intensity of the instability. Moreover, they enhance the temperature's diurnal range. These enhancements affect the pollutants deposition velocity and consequently the pollutants dispersion in the atmosphere.
Boundary-Layer Meteorol (2007) 124:324 DOI 10.1007/s10546-007-9170-0 ORIGINAL PAPER ... The surf... more Boundary-Layer Meteorol (2007) 124:324 DOI 10.1007/s10546-007-9170-0 ORIGINAL PAPER ... The surface energy balance and the mixing height in urban areas activities and recommendations of COST-Action 715 ... Martin Piringer · Sylvain Joffre · Alexander Baklanov · Andreas ...
... 7.5.2 Comparison between UHF profiler and RASS data .....152 7.6 THE MIXING HEIGHT DEDUCED FR... more ... 7.5.2 Comparison between UHF profiler and RASS data .....152 7.6 THE MIXING HEIGHT DEDUCED FROM ... in turn limits the dilution of the pollutants, and the urban plume may be ... As a rule-of-thumb, z* is somewhere between 2 5 hr (see ...
Journal of Wind Engineering and Industrial Aerodynamics, 1998
... Parameterization of convective and stable internal boundary layers into mass consistent model... more ... Parameterization of convective and stable internal boundary layers into mass consistent models. F. Castino * and M. Tombrou. ... E-mail: [email protected]. Journal of Wind Engineering and Industrial Aerodynamics Volumes 74-76, 1 April 1998, Pages 239-247. ...
This paper presents a new theory of the convective heat/mass transfer. It focuses on (i) advanced... more This paper presents a new theory of the convective heat/mass transfer. It focuses on (i) advanced treatment of turbulent mixing caused by large-scale semi-organised eddies overlooked in the classical theory and (ii) interactions between large eddies and surface roughness elements up to very high obstacles such as buildings, rocks and hills. Large-scale structures in the shear-free convective boundary layers consist of strong plumes and wider but weaker downdraughts. Close to the surface they cause local "convective winds" blowing towards the plume axes. The latter generate turbulence, in addition to its generation by the buoyancy forces, and strongly enhance turbulent fluxes of heat and other scalars. This mechanism is especially important over very rough surfaces. The proposed advanced model is validated against data from measurements over different sites and also through large-eddy simulation of convective boundary layers (CBLs) over a range of surfaces from very smooth to extremely rough. Excellent correspondence between model results, field observations and large-eddy simulations is achieved. The obtained resistance and heat/mass transfer laws are recommended for practical use in meso-scale, weather-prediction, climate and other environmental models.
The simulated nocturnal boundary layer height, h, from several widely used diagnostic relations a... more The simulated nocturnal boundary layer height, h, from several widely used diagnostic relations as well as from one prognostic relation, is compared with direct estimation of h, from radiosonde profiles available at 24h Z. The required input data are no more than surface wind speed, air temperature and total cloud cover. Of these, best performance is found using the relationship of Nieuwstadt [1]. It should also be mentioned that the comparison of estimations of h, against measurements improved when the observed height was determined at the maximum wind.
Results are presented from a windturbulence measurements campaign at the summit of ahill in compl... more Results are presented from a windturbulence measurements campaign at the summit of ahill in complex terrain in Andros island (Greece)where a wind turbine park has been constructed. Meanturbulence parameters and power spectra from three 30 mmasts located at the summit, upwind and downwind ofthe hill are analysed to ascertain the differencesfrom respective parameters in flat terrain and toassess the influence of the irregular topography. Thevariances of the horizontal (vertical) wind components are found tobe smaller (larger) than the onesfrom flat terrain. Of the available correlations forthe power spectra, the Von Karman one was found togive better results, although the low frequency partsshow pronounced lags. The asymmetry of the upwindterrain for different wind directions and especiallyits slope is clearly felt both by variances and byspectra. This influence, as expected, is found toincrease with increasing stability. These results havean important significance for wind turbine design andwind energy utilisation.
This study examines tropospheric ozone, its precursors and CO mixing ratios over Eu- rope during ... more This study examines tropospheric ozone, its precursors and CO mixing ratios over Eu- rope during 2001, using a modified version of the global three-dimensional chemical transport model (CTM) GEOS-CHEM. Our approach employs a methodology, identi- fied as a one-way nested grid formulation, to increase the horizontal resolution above the one adopted for the global scale. The nested grid methodology permits the treat- ment of chemistry over a particular region with relatively high horizontal resolution, while at the same time preserves the interaction of this region with the coarser global environment. The model is initially applied over the whole globe, including the nested domain. Then, the fine-resolution model is run for Europe with boundary conditions from the coarse global simulation. No feedback is applied in the coarse model. Differences between model results obtained using the nested grid and the coarse grid are discussed. Model calculations are compared to observations col- le...
modern atmosphere-hydrosphere-biosphere model chains, convective boundary-layer models and parame... more modern atmosphere-hydrosphere-biosphere model chains, convective boundary-layer models and parameterization packages represent the most important coupling agents, which essentially control the overall quality of predictions from coupled models. This paper focuses on the enhancement of turbulent mixing due to large-scale semi-organized eddies and interactions between large eddies and surface roughness elements up to very high obstacles such as buildings, rocks and hills. Large-scale structures in the shear-free convective boundary layers consist of strong plumes and wider but weaker downdraughts. Close to the surface they cause local ”convective winds“ blowing towards the plume axes. The latter generate turbulence, in addition to its generation by the buoyancy forces, and strongly contribute to the turbulent fluxes of heat and other scalars. This mechanism is especially important over very rough surfaces. The proposed model is validated against data from measurements over different sites and also through large-eddy simulation (LES) of convective boundary layers (CBLs) over a range of surfaces from very smooth to extremely rough. Excellent correspondence between model results, field observations and large-eddy simulations is achieved. The obtained resistance and heat/mass transfer laws are recommended for practical use inmeso-scale, weatherprediction, climate and other environmental models.
International Journal of Environment and Pollution, 2000
ABSTRACT This study tries to inform the user of the abilities and limitations of dispersion model... more ABSTRACT This study tries to inform the user of the abilities and limitations of dispersion models by comparing their differences in air pollution estimations. In particular, an intercomparison between the results of Eulerian and regulatory dispersion models for the new electric power plant in Rhodes Island is carried out, in order to emphasise their differences. The Eulerian models used in this study are Airpol and UAM, the latter also incorporating photochemistry. The input meteorological parameters and diffusion coefficients for both of these models are provided from the non-hydrostatic prognostic mesoscale meteorological model TVM. The regulatory models that have been used are Plumes and CTDMPLUS which are both Gaussian models and use hourly routine meteorological data as input. The simulations have been carried out for one year, and the worst results have been compared. A satisfactory agreement was found among the results for long-term predictions, while a spatial variation was observed for short-term predictions.
ABSTRACT This study analyzes air quality data provided by numerical simulations for the Greater A... more ABSTRACT This study analyzes air quality data provided by numerical simulations for the Greater Athens Area (GAA) using the latest release of the emission inventory (industry, traffic, off road activities, airport, railway, harbor). The three-dimensional photochemical Urban Airshed Model (UAM-V) was coupled with the meteorological Mesoscale Model (MM5). All the simulated days favored high concentration levels of air pollutants. The concentrations of the air pollutants produced by the simulations were compared with routine measurements from the operating stations of the existing air pollution monitor network in Athens. The comparison revealed good agreement for the stations sited in the center of Athens while the observed discrepancies in a few suburban stations could be explained by the fact that few sectors (e.g. biogenic) are not included in the Athens emission inventory. Moreover, the importance of the VOCs reactivity on photochemical modeling, especially on ozone productivity, was investigated after constructing various speciation profiles of the VOCs emissions in agreement with the different land uses (urban, semi-urban). These profiles were derived from a large number of VOC species (about 200) contained in detailed emission inventories. Furthermore, the role of biogenic emissions was examined by incorporating the rural environments. Finally, a modeling contribution to the aerosols' concentration levels in the Greater Athens Area is attempted using the three dimensional Regional Modeling System for Aerosols and Deposition (REMSAD). The aerosol distribution/deposition and toxic chemistry is examined, making use of the emissions of particulate matter included in the emission inventory such as PM, NH3 and toxics (Hg, Pb, Zn, As, Cu). Further simulations are performed by considering changes in the PM speciation. Finally, the correlation between the gaseous pollutants and the aerosol species is performed in order to provide important conclusions in areas or time-periods lacking PM measurements.
The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated ... more The physical and chemical characteristics of aircraft plumes at the take-off phase are simulated with the mesoscale CAMx model using the individual plume segment approach, in a highly resolved domain, covering the Athens International Airport. Emission indices during take-off measured at the Athens International Airport are incorporated. Model predictions are compared with in situ point and path-averaged observations (NO, NO₂) downwind of the runway at the ground. The influence of modeling process, dispersion properties and background air composition on the chemical evolution of the aircraft plumes is examined. It is proven that the mixing properties mainly determine the plume dispersion. The initial plume properties become significant for the selection of the appropriate vertical resolution. Besides these factors, the background NOx and O₃ concentration levels control NOx distribution and their conversion to nitrogen reservoir species.
Integrated environmental management in urban areas is nowadays considered a sine qua non objectiv... more Integrated environmental management in urban areas is nowadays considered a sine qua non objective of Community and national environmental and development policies. A large amount of scientific information on the state of the environment is now available from a large pool of data sources. This work presents an innovative method for integration of these data sources and effective coupling of environmental information with appropriate models and decision-support tools. State-ofthe-art Earth observation techniques, ground-based air quality measurements, atmospheric transport and chemical modelling, and multi-criteria decision-aid systems are used in an integrated information fusion environment in support of environmental and health impact assessment and decision-making at the urban and regional scales. Results of the pilot application of the method in the area of Lombardy in Northern Italy demonstrate the validity and usefulness of this novel approach.
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003
The current state of the art in air quality assessment, monitoring and management comprises analy... more The current state of the art in air quality assessment, monitoring and management comprises analytical measurements and atmospheric transport modeling. Earth observation from satellites provides an additional information layer through the calculation of synoptic air pollution indicators, such as atmospheric turbidity. Fusion of these data sources with ancillary data, including classification of population vulnerability to the adverse health effects of particulate pollution in the ambient air integrates them into an optimally managed environmental information processing tool. The computational assessment method described in this work permits a detailed spatial characterization of the domain of interest with a view to optimizing air quality management in order to reduce the corresponding adverse health impact. Results from the pilot application of this technique for integrated environmental and health assessment in the urban environment are given.
In the present study the horizontal distribution of columnar aerosol optical thicknessderived at ... more In the present study the horizontal distribution of columnar aerosol optical thicknessderived at high spatial resolution from Earth observation satellite data in the Lombardy area (Italy) was converted to the horizontal distribution of optically effective aerosols concentration at the ground level. This was achieved by incorporating information on atmosphere's mixing height, at which pollutants released at ground level are vertically
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Papers by M. Tombrou