|
|
Spatio-temporal distribution of atmospheric aerosol in urban and rural environment
Bendl, Jan ; Hovorka, Jan (advisor) ; Mikuška, Pavel (referee) ; Vojtíšek, Michal (referee)
Air quality in Europe remains a significant environmental concern, affecting the health and quality of life of its population. While stationary network ambient air quality monitoring allows for the observation of main trends, it is not fully representative of personal exposure of citizens due to high spatio-temporal variability of atmospheric aerosol. Therefore, highly time-and- space resolved measurements with state-of-the-art instruments and methods are needed to observe the aerosol variability, dynamics, identify hot-spots, and pollution sources, which are necessary for successful targeted mitigation measures. This thesis addresses this gap focusing on the characterization of spatio-temporal distribution of atmospheric aerosol in inhabited environments. Novel mobile measurement systems were developed and employed to investigate diverse environments, including rural, urban and suburban area. Aerosol source-apportionment were conducted, and the toxicological effects associated with these environments were also investigated. A novel mobile measurement system was developed for personal exposure measurements and pollution mapping in urban and rural environments. The system was used to measure air quality in the Munich subway, revealing high aerosol dynamics with significantly higher concentrations of...
|
|
|
Urban Ventilation Dependence on Geometric Configuration
Kukačka, Libor ; Jaňour, Zbyněk (advisor) ; Carpentieri, Matteo (referee) ; Uruba, Václav (referee)
Title: Urban Ventilation Dependence on Geometric Configuration Author: RNDr. Ing. Libor Kukačka Department: Department of Atmospheric Physics Supervisor: prof. RNDr. Zbyněk Jaňour, DrSc., Academy of Sciences of the Czech Republic, Institute of Thermomechanics, v. v. i. Abstract: The main goal of the thesis is to investigate the impact of urban geometry on the urban ventilation using wind-tunnel modelling. To measure the pollutant transport, both advective and turbulent, within complex urban geometries with a high temporal resolution a special measurement method was developed. At first, the pollution of a simplified urban area was simulated by a ground-level point source and the ventilation of the intersection with respect to four wind directions was studied. Later, the pollution of other simplified and complex urban areas was simulated by a ground-level line source and the ventilation of three different street canyons with respect to wind direction perpendicular and oblique to their along-canyon axis was investigated. The clear impact of urban complexity and wind direction on street canyon ventilation is demonstrated at lateral and top openings of all investigated canyons and the intersection. Whilst the dominance of the pollutant advection is demonstrated at the eaves of pitched roofs, at the roof ridges...
|
|
|
Dynamics of vertical and horizontal profiles of atmospheric aerosol in planetary boundary layer
Esterlová, Jana ; Hovorka, Jan (advisor) ; Jančík, Petr (referee)
The boundary layer of the atmosphere is a layer of air with thickness about 1 km above the ground. Open-cast mining is one of activities that polutes the air in this layer. It generates particulate matter (PM) mostly in size of aerodynamic diameter 1 - 10 µm - coarse patricles. The companies that does the mining pays for their emissions due to the law. However, these emissions are not experimentraly measured, they are calculated from given equation consisting of factors like the size of mining area, etc. Some papers have shown significantly higher concentrations of Coarse particles (or PM10) in surroundings of the mine. Other papers have found out that the origin of these high concentrations didn't come from the mining activities but is caused due to the activities at the place of measuring or nearby. There aren't many papers that measure the PM concentrations in the air in the mining area. This thesis shows the results of airship measurements in the air layers of the open-cast mine and above them. The experimentral site was brown coal mine Bílina in the North of The Czech Republic in important mining area. The measurements took place in December 2017. For measuring the number and mass concentrations was used APS - Aerodynamic Particle Sizes Spektrometr by TSI which sorts out the data into...
|
|
|
Flow and diffusion characteristics inside the urban area
Chaloupecká, Hana ; Jaňour, Zbyněk (advisor) ; Brechler, Josef (referee)
Title: Flow and diffusion characteristics inside the urban area Author: Hana Chaloupecká Department: Department of meteorology and enviroment protection Supervisor: prof. RNDr. Zbyněk Jaňour, DrSc., IT AS CR, v. v. i. Supervisor's e - mail: janour@it.cas.cz Abstract: Uniqueness of different towns, consists of various shapes of buildings. The main topic of this work is to compare concentration diffusion within groups of buildings of various types. We pursued houses made of single blocks of two different lengths - they were placed parallel or in courtyards. For research of pollution diffusion within the housing estates a method of physical modelling has been used. For this purpose we summarized a theory of atmospheric boundary layer and physical modelling at first. Then we pursued experiments. Measuring took place in a model in scale 1 : 300 inside an aerodynamic wind tunnel of the Institute of Thermomechanics AS in Nový Knín. We checked out the requirements placed on similarity of the real boundary layer and boundary layer modelled in the tunnel. By the measuring of concentration in urban areas we weren't watching a plume from the pollution source but we were studying an inversion task. We measured concentrations in two fixed points from different point sources inside the defined areas. A sensitivity of...
|
|
|
Atmospheric greenhouse gases - new type of measurements in the Czech Republic
Čermáková, Lenka ; Sedlák, Pavel (advisor) ; Zíková, Naděžda (referee)
The current condition, development and functioning of ecosystems is greatly influenced by the ongoing global change, which is probably caused by the increased concentrations of greenhouse gases in the atmosphere originating from human activity. Ecosystems are able to some extent cope with the consequences of global change on their own, and therefore ensure their future preservation. To understand the forces driving global change, we need detailed quality data from long-term observation. Quantification of substance and energy flows in different ecosystems and ecosystem valuation ability to bind air carbon allows us to model their development, both in current conditions and under conditions of global change. This thesis presents the current research methods of atmospheric boundary layer flows, while highlighting their advantages and pointing out their drawbacks. It also enables a better understanding of new methods of observation through the tall towers. The thesis presents some of the existing tall towers and describes their ways and methods of measurement. A part of the thesis is devoted to a tall tower which is planned to be built in the Czech Republic between municipalities Košetice and Křešín u Pacova. It provides an overview of methods, instrumental and technical equipment and facilities of the new tall...
|
|
|
Vertical temperature profile in atmospheric boundary layer
Gvoždíková, Blanka ; Pešice, Petr (advisor) ; Sedlák, Pavel (referee)
Submitted bachelor thesis discusses the issue of the atmospheric boundary layer. First of all, it addresses the boundary layer's thermal characteristics which are very variable near the Earth's surface. For this purpose we have chosen the observatory in Kopisty near Most where a tower meteorological measurement is performed. In addition the air temperature measurements from Milešovka observatory were included to a dataset, too. It is assumed that this mountain weather station due to its position can represent conditions of the free atmosphere. But if we compare some thermal characteristics of the air at different height levels, we'll figure out that the air temperature measurements at Milešovka are highly influenced by radiation balance of the Earth's surface. Despite this fact, the analysis of air layer between Kopisty and Milešovka gives an idea of a continuous-time behavior of air temperature characteristics. This bachelor thesis describes in detail the air temperature variations and the temperature lapse rate variations in several height levels, the variability of thermal stratification or the incidence and extent of air temperature inversions.
|
|
|
Mathematical modelling of air-flow in geometrically complicated areas
Fuka, Vladimír ; Brechler, Josef (advisor) ; Fürst, Jiří (referee) ; Jaňour, Zbyněk (referee)
The Charles University Large-eddy Microscale Model (CLMM) and its application are presented. It is a numerical model for simulation of turbulent flow and dispersion in the planetary boundary layer. CLMM solves the incompressible Navier-Stokes equations in the Boussinesq approximation and describes turbulence using the large eddy simulation. Three applications of the model are presented. In the first case, the model is applied to the stable boundary layer over a flat terrain. The second case presents the simulations of stably stratified flows over obstacles. The last case deals with the dispersion of a hazardous material within an urban canopy. It was performed in the frame of the COST Action ES1006 and uses the Michelstadt flow and dispersion dataset for model validation.
|
|
|
Microscale flow and diffusion characteristics inside the urban area
Kukačka, Libor
Title: Microscale flow and diffusion characteristics inside the urban area Author: Libor Kukačka Department: Department of meteorology and enviroment protection Supervisor: prof. RNDr. Zbyněk Jaňour, DrSc., IT AS CR, v.v.i. Supervisor's e-mail address: janour@it.cas.cz Abstract: Dispersion of pollutants in the atmosphere of urban areas is the important task in environmental sciences. The main goal was the quantitative studying of a flow in a symmetrical urban built-up area depending on a running on flow direction. There was given a theoretical base of the physical modelling of the atmospheric boundary layer in this work. The measurement was done with a model of the urban build-up area at a scale of 1:200 in the aerodynamic wind tunnel of the IT AS CR, v.v.i. in Nový Knín. The requirements to the similarity to a real atmospheric boundary layer and a model boundary layer in the wind tunnel were accomplished. Velocity fields, concentration fields and fields of scalar fluxes were measured in the area of a rectangular intersection. Results of the experiment showed significant sensitivity of the velocity field about the running on flow direction that extensively influenced ventilation of street canyons. Keywords: air pollution, atmospheric boundary layer, physical modelling, dispersion of passive contaminant,...
|
|
|
Dynamics of vertical and horizontal profiles of atmospheric aerosol in planetary boundary layer
Esterlová, Jana ; Hovorka, Jan (advisor) ; Jančík, Petr (referee)
The boundary layer of the atmosphere is a layer of air with thickness about 1 km above the ground. Open-cast mining is one of activities that polutes the air in this layer. It generates particulate matter (PM) mostly in size of aerodynamic diameter 1 - 10 µm - coarse patricles. The companies that does the mining pays for their emissions due to the law. However, these emissions are not experimentraly measured, they are calculated from given equation consisting of factors like the size of mining area, etc. Some papers have shown significantly higher concentrations of Coarse particles (or PM10) in surroundings of the mine. Other papers have found out that the origin of these high concentrations didn't come from the mining activities but is caused due to the activities at the place of measuring or nearby. There aren't many papers that measure the PM concentrations in the air in the mining area. This thesis shows the results of airship measurements in the air layers of the open-cast mine and above them. The experimentral site was brown coal mine Bílina in the North of The Czech Republic in important mining area. The measurements took place in December 2017. For measuring the number and mass concentrations was used APS - Aerodynamic Particle Sizes Spektrometr by TSI which sorts out the data into...
|
|
|
Urban Ventilation Dependence on Geometric Configuration
Kukačka, Libor ; Jaňour, Zbyněk (advisor) ; Carpentieri, Matteo (referee) ; Uruba, Václav (referee)
Title: Urban Ventilation Dependence on Geometric Configuration Author: RNDr. Ing. Libor Kukačka Department: Department of Atmospheric Physics Supervisor: prof. RNDr. Zbyněk Jaňour, DrSc., Academy of Sciences of the Czech Republic, Institute of Thermomechanics, v. v. i. Abstract: The main goal of the thesis is to investigate the impact of urban geometry on the urban ventilation using wind-tunnel modelling. To measure the pollutant transport, both advective and turbulent, within complex urban geometries with a high temporal resolution a special measurement method was developed. At first, the pollution of a simplified urban area was simulated by a ground-level point source and the ventilation of the intersection with respect to four wind directions was studied. Later, the pollution of other simplified and complex urban areas was simulated by a ground-level line source and the ventilation of three different street canyons with respect to wind direction perpendicular and oblique to their along-canyon axis was investigated. The clear impact of urban complexity and wind direction on street canyon ventilation is demonstrated at lateral and top openings of all investigated canyons and the intersection. Whilst the dominance of the pollutant advection is demonstrated at the eaves of pitched roofs, at the roof ridges...
|
guest ::
