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Application of diffusive samplers for ambient ozone measurements
Cepáková, Šárka ; Hůnová, Iva (advisor) ; Přibil, Rudolf (referee)
Diffuse sampling is based on free flow of analyte molecules from the sampled medium to a collecting medium. This method is used for quantifying ambient, gaseous air pollutant concentrations. Diffuse monitoring offers a geographical concentration distribution. It is available choice for measuring ambient ozone. Today, tropospheric ozone belongs to the most problematic pollutants in the atmosphere. And thatś why it is useful to monitor spatial and temporal variations in the amount of this pollutant. The offer of diffuse samplers for monitoring ambient ozone concentration is wide enough - the most widely used samplers are for example Gradko, Ogawa, Radiello or IVL.
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Temporal and spatial analysis of ozone in the Jizerske hory Mts.
Stoklasová, Petra ; Hůnová, Iva (advisor) ; Matoušková, Leona (referee)
The aim of this thesis is to analyze and evaluate temporal and spatial patterns of concentrations of ambient ozone in the CHKO Jizerské hory. The Jizerské hory Mts. are an area where one of the highest concentrations of ambient ozone are measured every year and, therefore, our attention was focused on this area. The measurements were carried out between 2006 and 2010 at 13 sites (714-1000 m n. m.) in the CHKO Jizerské hory. From the input data, which were fortnightly average nitrate concentrations created on the filters of Ogawa passive samplers, fortnightly average concentrations of ambient ozone were computed using the empirical flow. Ambient ozone concentrations ranged from 13,8 ppb (year 2007) to 72,1 ppb (year 2006). From the five-year period under study defy the year 2006, when the highest concentrations of ambient ozone were measured. The lowest concentrations occurred in 2009. In all years, the concentrations of ambient ozone increased with increasing elevation and this gradient ranged from 2,7 to 4,6 ppb on 100 meters altitude. The accuracy and precision of measurement was very good (accuracy: R2 = 82 %; precision: R2 = 98 %). By multiple linear regression it was found, that ambient ozone concentration are influenced, in addition to the altitude, by ozone concentrations from previous...
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Temporal and spatial analysis of ozone in the Jizerske hory Mts.
Stoklasová, Petra ; Hůnová, Iva (advisor) ; Matoušková, Leona (referee)
The aim of this thesis is to analyze and evaluate temporal and spatial patterns of concentrations of ambient ozone in the CHKO Jizerské hory. The Jizerské hory Mts. are an area where one of the highest concentrations of ambient ozone are measured every year and, therefore, our attention was focused on this area. The measurements were carried out between 2006 and 2010 at 13 sites (714-1000 m n. m.) in the CHKO Jizerské hory. From the input data, which were fortnightly average nitrate concentrations created on the filters of Ogawa passive samplers, fortnightly average concentrations of ambient ozone were computed using the empirical flow. Ambient ozone concentrations ranged from 13,8 ppb (year 2007) to 72,1 ppb (year 2006). From the five-year period under study defy the year 2006, when the highest concentrations of ambient ozone were measured. The lowest concentrations occurred in 2009. In all years, the concentrations of ambient ozone increased with increasing elevation and this gradient ranged from 2,7 to 4,6 ppb on 100 meters altitude. The accuracy and precision of measurement was very good (accuracy: R2 = 82 %; precision: R2 = 98 %). By multiple linear regression it was found, that ambient ozone concentration are influenced, in addition to the altitude, by ozone concentrations from previous...
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Ambient ozon impact on vegetation
Bystrianský, Martin ; Hůnová, Iva (advisor) ; Čabala, Radomír (referee)
Bystrianský: Ambient ozone impact on vegetation - Abstract Ambient ozone is present in the air all around the world. It is natural component of the atmosphere, due to anthropogenic emissions of ozone precursors its concentration rise. That is unlikely, because ozone is toxic. Ozone is formed as a part of photochemical smog from ozone precursors by photochemical reactions. As ozone precursors nitrogen oxides (NOx) and volatile organic compounds (VOC) are called. Their main source is car traffic. Danger of ozone lies in its reactivity. It oxidizes most of organic compounds, especially those containing double bonds. These are present in membrane lipids. Furthermore, ozone forms more reactive compounds than itself - active oxygen species (AOS), free radicals. Ozone effects negatively both human health and vegetation. Ozone disrupts structure of the cells, which for plants means destroy of leaves and needles, photosynthesis disruption and biomass loss. For that, plants have antioxidants system for AOS scavenging. But it has little effect, when concentration of ozone is high during smog period. Therefore, limits for maximal concentration of ozone in the ambient air are set.
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Estimation of exposure index for surface ozone AOT40 from diffusive sampler measurements
Pavlíková, Monika ; Hůnová, Iva (advisor) ; Matoušková, Leona (referee)
The study summerizes methods of ozone AOT40 index estimation from time intergarated passive sampler measurements in forests. Ground-level ozone is a highly phytotoxic atmospheric pollutant. In recent years negative impacts of elevated concentrations of ground-level ozone on vegetation and ecosystems have been studied and atmospheric levels of ozone have been measured. There is a noticeable negative impact of elevated concentrations of ground-level ozone on forests in the Czech Republic, mainly in rural areas that are far away from the emission sources. The AOT40F exposure index is a tool to assess the geographical areas with vegetation potentially at risk due to elevated ground-level ozone concentrations. The AOT40 index is the accumulated hourly exposure during daytime hours above cut-off concentration of 40 ppb, during the growing season. Passive samplers are used for measuring ground-level ozone in high spatial resolution. Passive samplers are easy to use. However this metod provides time intergrated values of pollutant concentrations (1-2 weeks). It is not possible to estimate AOT40 index by using just data of mean ozone concentrations over the sampling period. Three methods were used to estimate the exposure index AOT40F for forests by mean ozone concentrations measured in the Jizerské Hory...
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Application of diffusive samplers for ambient ozone measurements
Cepáková, Šárka ; Přibil, Rudolf (referee) ; Hůnová, Iva (advisor)
Diffuse sampling is based on free flow of analyte molecules from the sampled medium to a collecting medium. This method is used for quantifying ambient, gaseous air pollutant concentrations. Diffuse monitoring offers a geographical concentration distribution. It is available choice for measuring ambient ozone. Today, tropospheric ozone belongs to the most problematic pollutants in the atmosphere. And thatś why it is useful to monitor spatial and temporal variations in the amount of this pollutant. The offer of diffuse samplers for monitoring ambient ozone concentration is wide enough - the most widely used samplers are for example Gradko, Ogawa, Radiello or IVL.
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