... Page 3. component of the particle motion is obtained by solving a 3D form of the Langevin equ... more ... Page 3. component of the particle motion is obtained by solving a 3D form of the Langevin equation for the random velocity (Thomson, 1987). ... Thomson DJ 1987: Criteria for the selection of stochastic models of particle trajectories in turbulent flows. J. Fluid Mech., 180, 529–556. ...
ABSTRACT Summary A physical simulation in hydraulic channel has been performed, concerning the be... more ABSTRACT Summary A physical simulation in hydraulic channel has been performed, concerning the behaviour of buoyant and neutral plumes in the presence of a building of schematic shape placed near the stack. The effect of the aerodynamic wake, due to the stack itself and to the building, on the plume geometrical behaviour has been studied. This was done for various stack-building relative positions and letting both the ratios between exit and wind velocity and between stack and building height vary. The aim of the experiment was to confirm or better define the simple criteria normally applied for excluding in practical cases the occurrence of dangerous plume trapping phenomena. The results confirm these criteria and even suggest the possibility of relaxing them slightly. The simulation also allowed an indirect check of the validity of Briggs and Bryant plume rise models, as well as a study of the plume radius trendvs. distance from the source andvs. rise above the emission height. Particularly interesting in this context is the fact that the data put into evidence an enlarged plume spread in the cases of partial trapping with respect to the imperturbed cases and that the linear entrainment relationship between radius and rise is reassessed, with an entrainment parameter β=0.6 as in the atmosphere in the case of buoyant plumes.
19th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, Harmo 2019, 2019
A multi-scale modelling system was developed to provide hourly NOx concentrations field at buildi... more A multi-scale modelling system was developed to provide hourly NOx concentrations field at building resolving scale in the urban area of Modena. The WRF-Chem model was employed with aim of reproducing local background concentrations taking into account meteorological and chemical transformation at regional scale, conversely the PMSS modelling system was applied to simulate 3D air pollutant dispersion with a very high-resolution (4 m) on a 6 km x 6 km domain. Modelled NOx concentrations reproduced by this modelling system show a good agreement with observation at both traffic and background urban stations
Abstract On-road particulate matter (PM) mass was measured during a sampling campaign in March of... more Abstract On-road particulate matter (PM) mass was measured during a sampling campaign in March of 2015 in the ‘4 giornate’ tunnel in Naples, Italy. Two sets of samples were collected at both sides of the tunnel, each set representing the daily cycle at a 1 h time resolution. Distance-based – mass per kilometer – and fuel-based – mass per burned fuel – emission factors (EFs) were calculated using mass concentrations, traffic flow rates and wind speed as a function of fleet composition. Also, chemical analyses were performed for polycyclic aromatic hydrocarbons (PAHs). Due to the high traffic volume, particle mass concentration at the tunnel exit was always significantly elevated relative to entrance concentration; depending on the hour of the day, PM10 concentration ranged between 300 μg/m3, during the early afternoon, and 600 μg/m3 during rush hours at the tunnel exit. Correspondingly, PAHs achieved concentrations as high as 1450 ng/m3, and benzo(a)pyrene, a surely carcinogenic compound, achieved concentrations as high as 69 ng/m3, raising serious concerns in relation to population exposure close to this urban tunnel. Distance-based and fuel-based emission factors for CO2, PM10 and PAHs were estimated, but while the EF for CO2 was within the range of expected values, the present study found much higher EFs for particulate matter and PAHs. According to the national official statistics from ISPRA (the Italian Institute for the Protection and Research on Environment), derived from the COPERT database, we expected an EF for particulate matter of about 55 mg/km, but the EF estimated from measurements taken at both sides of the tunnel was about four times higher than that expected; also, benzo(a)pyrene achieved an average EF of 2.7 μg/km, about three times higher than that expected from the ISPRA database.
Summary Eliothermoelectric plants require, for both their optimal operation and safety requireme... more Summary Eliothermoelectric plants require, for both their optimal operation and safety requirements, information on frequency distributions of extreme value occurrence in solar and meteorological parameters. In particular, the predictability of the onset of strong winds and solar intermittency frequency distributions are needed. This study presents some interesting results obtained at the Eurelios power plant of Adrano (Sicily).
AST2 is a PC interactive package studied to allow the user a guided analysis of the cause-effect ... more AST2 is a PC interactive package studied to allow the user a guided analysis of the cause-effect relations Although a particular example has been chosen in between two variables. In addition to a simpler multi-this paper to review the single steps, AST2 has surely variate cross-correlatlons analysis, a more complete and a more general utilization both in environmental proreliable causality test has been implemented; this test
Air Pollution Modeling and Its Application X, 1994
A particle model SPRAY suitable for dealing with the atmospheric dispersion of buoyant emission i... more A particle model SPRAY suitable for dealing with the atmospheric dispersion of buoyant emission in complex terrain has been developed. It is an extension of the model LAMBDA (Anfossi et al. 1991, Brusasca et al. 1989 and 1992) based on the Langevin equation, designed to simulate the dispersion on flat terrain, which was validated in various atmospheric conditions. In this last model the vertical profiles of wind and turbulence, defined at the source locations, were kept constant in all the computational domain.
Biosphere-Atmosphere Exchange of Pollutants and Trace Substances, 1997
ENEL SpA/ CRAM, Environment and Material Research Centre of the Italian Electricity Company, in c... more ENEL SpA/ CRAM, Environment and Material Research Centre of the Italian Electricity Company, in collaboration with the Environmental Department of CISE, has been developing a long term project since 1992, in order to evaluate the contribution of deposition phenomena in the environmental problems related to atmospheric acidity. This activity is carried out at the meteorological station of San Pietro Capofiume, located in the Po river plain, a rural region in northern Italy affected by anthropogenic pollution events. This project also aims to study dry deposition over a long period in the Mediterranean area. Direct measurements of meteorological and chemical parameters were used to run inferential technique models, in order to quantify dry deposition. The big-leaf and multi-layer approaches were both tested. Concentrations of SO2, NO2, NO and O3 were measured with half an hour resolution, using automatic analysers. During the vegetative season, concentration of gaseous species as SO2, NO2, HNO2, HNO3, NH3 and fine particulate as SO4 2− NO3 − and NH4 + were measured weekly, by an annular denuder system. In 1993, during the vegetative season, an intercomparison campaign was performed at S. Pietro Capofiume to test an inferential technique against eddy correlation ozone fluxes. The results of this comparison and the annual dry deposition fluxes are presented.
Air Pollution Modeling and Its Application IX, 1992
APC code has been developed to control the environmental impact of point sources emitted gases or... more APC code has been developed to control the environmental impact of point sources emitted gases or aerosols in the atmosphere.
Air Pollution Modeling and Its Application VIII, 1991
A Monte Carlo particle model for simulating pollutant dispersion in the atmosphere has been devel... more A Monte Carlo particle model for simulating pollutant dispersion in the atmosphere has been developed by our team. Its ability to predict ground level concentrations (g.I.c.) is verified against experimental data from the Karlsruhe Nuclear Research Center (F.R.G.). Tracer data were also compared to the simulations of 10 different Gaussian models in order to prove the particle model performances against simple and widely used models. A complete “model evaluation” was carried out: particle model yields satisfactory results and shows performances which are significantly better than all the Gaussian models.
Nuovo Cimento della Societa Italiana di Fisica C, 2006
The ozone column depletion over the western coast of South America has been previously explained,... more The ozone column depletion over the western coast of South America has been previously explained, based on the existence of winds in the area of the depletion, which cause compression and thinning of the ozone layer. However, the presence of humidity and methane transported by these winds to the stratosphere where the ozone depletion is present gives evidence that these compounds also participate in the depletion of the ozone layer. These two compounds, humidity and methane, are analysed during the ozone depletion of January, 1998. It is observed that when humidity presents fluctuations, ozone has fluctuations too. A maximum of humidity corresponds to a minimum of ozone, but there is a shift in altitude between them. This shift is observed in the stratosphere and upper troposphere and corresponds to approximately 500 m. It is important to point out that during this event El Niño was present and the sources of methane are the Amazon forest and the Pacific Ocean. The data for this study was obtained from NASA and HALOE.
In many developed countries projects about alerting system for weather and other event have been ... more In many developed countries projects about alerting system for weather and other event have been set up. For example, in the case of flood, European action NAHA (Natural Hazard) action has the specific objectives of develop and test in real time a pre-...
Quarterly Journal of the Royal Meteorological Society, 1989
Numerical experiments with a two-dimensional model have been performed to study diurnal urban cir... more Numerical experiments with a two-dimensional model have been performed to study diurnal urban circulation and heat islands in calm conditions. Vertical structures of rural and urban planetary boundary layers, heat island intensities and circulations are examined in different conditions of stability, surface heat fluxes and city width. A simple expression to predict diurnal evolution of the urban-rural temperature difference is proposed.
Quarterly Journal of the Royal Meteorological Society, 1983
ABSTRACT A quasi-geostrophic mean flow can form the basic state upon which a sea breeze is superi... more ABSTRACT A quasi-geostrophic mean flow can form the basic state upon which a sea breeze is superimposed; a model is described. With a mean flow perpendicular to the coast the speed of the sea breeze front is shown to be a linear function of the onshore component of the mean flow. When a constant mean flow is introduced the general structure of the sea breeze is unchanged. In particular, for a constant energy input the intensity is also unaltered. In contrast, a shear changes the general qualitative structure but leaves the speed of the front and the intensity of the sea breeze unchanged. These features are consistent with the available potential energy of the system and a constant transfer, per unit area, of this into kinetic energy. Model results and other studies are discussed.
Il rapporto si propone di fornire un supporto ai tecnici impegnati nel controllo della qualità de... more Il rapporto si propone di fornire un supporto ai tecnici impegnati nel controllo della qualità dell'aria nell'utilizzo dei modelli matematici per migliorare la gestione della qualità dell'aria. Vengono prese in esame le caratteristiche generali dei modelli stocastici e deterministici ...
International Journal of Environment and Pollution, 2015
In 1991, three institutions from Slovenia and Italy performed a measuring campaign to collect dat... more In 1991, three institutions from Slovenia and Italy performed a measuring campaign to collect data for the validation of air pollution dispersion models. The target was a local area around the Šoštanj Thermal Power Plant in northeast Slovenia. As one of the co-authors of the work we decided to renew the database and to produce the necessary up-to-date information that would allow other researchers to use this experimental database for modern models testing. The measurements data set describes in detail the following situation: Šoštanj Thermal Power Plant at that time did not have any desulphurisation plants, therefore the sulphur dioxide (SO 2) continuously emitted from its blocks was acting like a tracer in the environment. The area is characterised by very complex meteorological situations. In the paper we will present a description of the experiment (area description, site, terrain, measurement stations location, database) and two most interesting cases suitable for a model validation (emission, ambient concentrations, meteorology).
... Page 3. component of the particle motion is obtained by solving a 3D form of the Langevin equ... more ... Page 3. component of the particle motion is obtained by solving a 3D form of the Langevin equation for the random velocity (Thomson, 1987). ... Thomson DJ 1987: Criteria for the selection of stochastic models of particle trajectories in turbulent flows. J. Fluid Mech., 180, 529–556. ...
ABSTRACT Summary A physical simulation in hydraulic channel has been performed, concerning the be... more ABSTRACT Summary A physical simulation in hydraulic channel has been performed, concerning the behaviour of buoyant and neutral plumes in the presence of a building of schematic shape placed near the stack. The effect of the aerodynamic wake, due to the stack itself and to the building, on the plume geometrical behaviour has been studied. This was done for various stack-building relative positions and letting both the ratios between exit and wind velocity and between stack and building height vary. The aim of the experiment was to confirm or better define the simple criteria normally applied for excluding in practical cases the occurrence of dangerous plume trapping phenomena. The results confirm these criteria and even suggest the possibility of relaxing them slightly. The simulation also allowed an indirect check of the validity of Briggs and Bryant plume rise models, as well as a study of the plume radius trendvs. distance from the source andvs. rise above the emission height. Particularly interesting in this context is the fact that the data put into evidence an enlarged plume spread in the cases of partial trapping with respect to the imperturbed cases and that the linear entrainment relationship between radius and rise is reassessed, with an entrainment parameter β=0.6 as in the atmosphere in the case of buoyant plumes.
19th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, Harmo 2019, 2019
A multi-scale modelling system was developed to provide hourly NOx concentrations field at buildi... more A multi-scale modelling system was developed to provide hourly NOx concentrations field at building resolving scale in the urban area of Modena. The WRF-Chem model was employed with aim of reproducing local background concentrations taking into account meteorological and chemical transformation at regional scale, conversely the PMSS modelling system was applied to simulate 3D air pollutant dispersion with a very high-resolution (4 m) on a 6 km x 6 km domain. Modelled NOx concentrations reproduced by this modelling system show a good agreement with observation at both traffic and background urban stations
Abstract On-road particulate matter (PM) mass was measured during a sampling campaign in March of... more Abstract On-road particulate matter (PM) mass was measured during a sampling campaign in March of 2015 in the ‘4 giornate’ tunnel in Naples, Italy. Two sets of samples were collected at both sides of the tunnel, each set representing the daily cycle at a 1 h time resolution. Distance-based – mass per kilometer – and fuel-based – mass per burned fuel – emission factors (EFs) were calculated using mass concentrations, traffic flow rates and wind speed as a function of fleet composition. Also, chemical analyses were performed for polycyclic aromatic hydrocarbons (PAHs). Due to the high traffic volume, particle mass concentration at the tunnel exit was always significantly elevated relative to entrance concentration; depending on the hour of the day, PM10 concentration ranged between 300 μg/m3, during the early afternoon, and 600 μg/m3 during rush hours at the tunnel exit. Correspondingly, PAHs achieved concentrations as high as 1450 ng/m3, and benzo(a)pyrene, a surely carcinogenic compound, achieved concentrations as high as 69 ng/m3, raising serious concerns in relation to population exposure close to this urban tunnel. Distance-based and fuel-based emission factors for CO2, PM10 and PAHs were estimated, but while the EF for CO2 was within the range of expected values, the present study found much higher EFs for particulate matter and PAHs. According to the national official statistics from ISPRA (the Italian Institute for the Protection and Research on Environment), derived from the COPERT database, we expected an EF for particulate matter of about 55 mg/km, but the EF estimated from measurements taken at both sides of the tunnel was about four times higher than that expected; also, benzo(a)pyrene achieved an average EF of 2.7 μg/km, about three times higher than that expected from the ISPRA database.
Summary Eliothermoelectric plants require, for both their optimal operation and safety requireme... more Summary Eliothermoelectric plants require, for both their optimal operation and safety requirements, information on frequency distributions of extreme value occurrence in solar and meteorological parameters. In particular, the predictability of the onset of strong winds and solar intermittency frequency distributions are needed. This study presents some interesting results obtained at the Eurelios power plant of Adrano (Sicily).
AST2 is a PC interactive package studied to allow the user a guided analysis of the cause-effect ... more AST2 is a PC interactive package studied to allow the user a guided analysis of the cause-effect relations Although a particular example has been chosen in between two variables. In addition to a simpler multi-this paper to review the single steps, AST2 has surely variate cross-correlatlons analysis, a more complete and a more general utilization both in environmental proreliable causality test has been implemented; this test
Air Pollution Modeling and Its Application X, 1994
A particle model SPRAY suitable for dealing with the atmospheric dispersion of buoyant emission i... more A particle model SPRAY suitable for dealing with the atmospheric dispersion of buoyant emission in complex terrain has been developed. It is an extension of the model LAMBDA (Anfossi et al. 1991, Brusasca et al. 1989 and 1992) based on the Langevin equation, designed to simulate the dispersion on flat terrain, which was validated in various atmospheric conditions. In this last model the vertical profiles of wind and turbulence, defined at the source locations, were kept constant in all the computational domain.
Biosphere-Atmosphere Exchange of Pollutants and Trace Substances, 1997
ENEL SpA/ CRAM, Environment and Material Research Centre of the Italian Electricity Company, in c... more ENEL SpA/ CRAM, Environment and Material Research Centre of the Italian Electricity Company, in collaboration with the Environmental Department of CISE, has been developing a long term project since 1992, in order to evaluate the contribution of deposition phenomena in the environmental problems related to atmospheric acidity. This activity is carried out at the meteorological station of San Pietro Capofiume, located in the Po river plain, a rural region in northern Italy affected by anthropogenic pollution events. This project also aims to study dry deposition over a long period in the Mediterranean area. Direct measurements of meteorological and chemical parameters were used to run inferential technique models, in order to quantify dry deposition. The big-leaf and multi-layer approaches were both tested. Concentrations of SO2, NO2, NO and O3 were measured with half an hour resolution, using automatic analysers. During the vegetative season, concentration of gaseous species as SO2, NO2, HNO2, HNO3, NH3 and fine particulate as SO4 2− NO3 − and NH4 + were measured weekly, by an annular denuder system. In 1993, during the vegetative season, an intercomparison campaign was performed at S. Pietro Capofiume to test an inferential technique against eddy correlation ozone fluxes. The results of this comparison and the annual dry deposition fluxes are presented.
Air Pollution Modeling and Its Application IX, 1992
APC code has been developed to control the environmental impact of point sources emitted gases or... more APC code has been developed to control the environmental impact of point sources emitted gases or aerosols in the atmosphere.
Air Pollution Modeling and Its Application VIII, 1991
A Monte Carlo particle model for simulating pollutant dispersion in the atmosphere has been devel... more A Monte Carlo particle model for simulating pollutant dispersion in the atmosphere has been developed by our team. Its ability to predict ground level concentrations (g.I.c.) is verified against experimental data from the Karlsruhe Nuclear Research Center (F.R.G.). Tracer data were also compared to the simulations of 10 different Gaussian models in order to prove the particle model performances against simple and widely used models. A complete “model evaluation” was carried out: particle model yields satisfactory results and shows performances which are significantly better than all the Gaussian models.
Nuovo Cimento della Societa Italiana di Fisica C, 2006
The ozone column depletion over the western coast of South America has been previously explained,... more The ozone column depletion over the western coast of South America has been previously explained, based on the existence of winds in the area of the depletion, which cause compression and thinning of the ozone layer. However, the presence of humidity and methane transported by these winds to the stratosphere where the ozone depletion is present gives evidence that these compounds also participate in the depletion of the ozone layer. These two compounds, humidity and methane, are analysed during the ozone depletion of January, 1998. It is observed that when humidity presents fluctuations, ozone has fluctuations too. A maximum of humidity corresponds to a minimum of ozone, but there is a shift in altitude between them. This shift is observed in the stratosphere and upper troposphere and corresponds to approximately 500 m. It is important to point out that during this event El Niño was present and the sources of methane are the Amazon forest and the Pacific Ocean. The data for this study was obtained from NASA and HALOE.
In many developed countries projects about alerting system for weather and other event have been ... more In many developed countries projects about alerting system for weather and other event have been set up. For example, in the case of flood, European action NAHA (Natural Hazard) action has the specific objectives of develop and test in real time a pre-...
Quarterly Journal of the Royal Meteorological Society, 1989
Numerical experiments with a two-dimensional model have been performed to study diurnal urban cir... more Numerical experiments with a two-dimensional model have been performed to study diurnal urban circulation and heat islands in calm conditions. Vertical structures of rural and urban planetary boundary layers, heat island intensities and circulations are examined in different conditions of stability, surface heat fluxes and city width. A simple expression to predict diurnal evolution of the urban-rural temperature difference is proposed.
Quarterly Journal of the Royal Meteorological Society, 1983
ABSTRACT A quasi-geostrophic mean flow can form the basic state upon which a sea breeze is superi... more ABSTRACT A quasi-geostrophic mean flow can form the basic state upon which a sea breeze is superimposed; a model is described. With a mean flow perpendicular to the coast the speed of the sea breeze front is shown to be a linear function of the onshore component of the mean flow. When a constant mean flow is introduced the general structure of the sea breeze is unchanged. In particular, for a constant energy input the intensity is also unaltered. In contrast, a shear changes the general qualitative structure but leaves the speed of the front and the intensity of the sea breeze unchanged. These features are consistent with the available potential energy of the system and a constant transfer, per unit area, of this into kinetic energy. Model results and other studies are discussed.
Il rapporto si propone di fornire un supporto ai tecnici impegnati nel controllo della qualità de... more Il rapporto si propone di fornire un supporto ai tecnici impegnati nel controllo della qualità dell'aria nell'utilizzo dei modelli matematici per migliorare la gestione della qualità dell'aria. Vengono prese in esame le caratteristiche generali dei modelli stocastici e deterministici ...
International Journal of Environment and Pollution, 2015
In 1991, three institutions from Slovenia and Italy performed a measuring campaign to collect dat... more In 1991, three institutions from Slovenia and Italy performed a measuring campaign to collect data for the validation of air pollution dispersion models. The target was a local area around the Šoštanj Thermal Power Plant in northeast Slovenia. As one of the co-authors of the work we decided to renew the database and to produce the necessary up-to-date information that would allow other researchers to use this experimental database for modern models testing. The measurements data set describes in detail the following situation: Šoštanj Thermal Power Plant at that time did not have any desulphurisation plants, therefore the sulphur dioxide (SO 2) continuously emitted from its blocks was acting like a tracer in the environment. The area is characterised by very complex meteorological situations. In the paper we will present a description of the experiment (area description, site, terrain, measurement stations location, database) and two most interesting cases suitable for a model validation (emission, ambient concentrations, meteorology).
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Papers by G. Brusasca