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Measured and modelled fluxes of tropospheric ozone in mountainous Norway spruce forest
Juráň, Stanislav ; Zapletal, Miloš ; Večeřa, Zbyněk ; Cudlín, Pavel ; Urban, Otmar
Tropospheric ozone fluxes (O3) were measured in Norway spruce forest at Bily Kriz, Czech Republic by eddy covariance technique. Within-canopy concentration gradient was measured by APOA-370 analysers (Horiba, Japan) in 7m, 25m and 30m above ground. Fluxes of O3 were modelled from the concentration gradient by applying Inverse Lagrangian Transport Model (Raupach, 1989). Next, O3 fluxes were modelled on the basis of resistent analogy. Ozone flux measured by eddy covariance technique amounted up to 1.19 nmol m-2 s-1 on daily average and the lowest -0.75 nmol m-2 s-1. Studied forest stand was net sink for ozone in 7.14 mmol m-2 per day (=0.343 g m-2 per day). The highest ozone emission peaked during noon hours, suggesting closure of stomata due to low air temperature and ozone production due to sufficient radiation. Both models proved to be imprecise when compared to measured data in autumn-winter transition period.
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Utilization of sampling filters from the Kresin atmospheric station for further analysis
Vítková, Gabriela ; Kahoun, D. ; Strnadová, G. ; Hanuš, Vlastimil ; Petrov, M. ; Tříska, Jan ; Holoubek, Ivan
The Kresin At Pacov Atmospheric Station serves as a monitoring point for the occurrence and remote transmission of greenhouse gases, selected atmospheric pollutants and basic meteorological characteristics. The determination of the GHG concentration (CO2, CH4, N2O, CO) is carried out in air continuously sampled at 10, 50, 125 and 250 m heights. The analysis itself takes place at the foot of a high mast where the air is drawn through the tubes of Synflex 1300. lines and individual analyzers are protected from mechanical pollution by input filters that are changed at regular intervals as part of the routine maintenance of the device or earlier when unexpected clogging occurs. Analyzing these filters can provide additional information about the surrounding area. These are stainless filters (Swagelog „T“ filter) with a porosity of 40 μm. A sampling head is provided in front of them to protect them from rough dirt and water drops. The volume flow of the scrubbed air is about 15 l / min, the exchange interval is usually 3 months. The need to replace these filters has increased in recent months as the flow rate on the sampling lines has fallen. The question arises as to how long the filters remain fully passable and how well they serve their purpose without burdening the sampling system and lowering the measurement quality. The results of analyzes of polycyclic aromatic hydrocarbons (PAHs) carried out on filters at the Institute of Chemistry and Biochemistry of the Faculty of Science of South Bohemian University as well as images from the Scanning Electron Microscope (SEM) could be helpful in answering this question. On the basis of the preliminary results, we propose a more extensive study for the use of this waste material for the analysis of solid particles from the atmosphere in the surroundings of AS Křešín near Pacov and the optimization of the QA / QC sampling systems of greenhouse gas analyzers.
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Use of the ceilometer data to explainig changes in pollutants concetration gradient in the air during the day
Komínková, Kateřina ; Holoubek, Ivan
For the interpretation of air pollutants concentrations, the one of the key parameter is the atmospheric boundary layer (ABL) evolution during a day and night. The ABL is a broad concept that includes different states of airflow dynamics in the part of troposphere closest to the Earth's surface (0-2 km above the surface), which has an effect in this area. A lot of air flow changes occur in the ABL during the day. For the measurement of substances concentrations in the air the development of mixing layer (ML) in the light part of the day is very important. A lot of ground remote sensing methods was developed for determination of ABL height during the day, one of them which can be very simply operated is to use data from ceilometer. However, the obtained outputs cannot be directly interpreted. In addition, in the case of the terrain measurements a lot of cases when ABL height values cannot be determined because the ceilometer measurement is disturbed can occur.\n\n
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Design of the new generation integrated emission model
Resler, Jaroslav ; Juruš, Pavel ; Benešová, N. ; Vlček, O. ; Belda, M. ; Huszár, P. ; Krč, Pavel ; Eben, Kryštof
The only publicly available and widely used tool for emission modelling for CTM is the processor SMOKE (Coats & Carlie, 1996), but its usage is limited by its strong dependence on conditions of USA. A few attempts to adjust SMOKE to other conditions were made in the past - see e.g. works reported in Bieser et al., 2011 or Borge et al., 2008, but the efforts hit the limits of its design. Our goal is to develop an emission processor based on open technologies which will be easy to use for typical usage with CTM in our conditions and which will be flexible and configurable enough to serve specific needs of users in other countries over the world.
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Modelling assessment of scenarios of urban development to air quality and thermal comfort at street level
Resler, Jaroslav ; Krč, Pavel ; Belda, Michal ; Juruš, Pavel ; Benešová, N. ; Vlček, O. ; Damašková, D. ; Eben, Kryštof ; Derbek, P.
A new model for simulations of urban environment USM was developed and integrated into LES model PALM inside the project UrbanAdapt. The model allows simulations of air flow, radiation, air temperature and temperature of materials, air pollution and indices MRT and PET in fine resolution. The surrounding of a crossroad of the streets Komunardu and Delnicka in Praha-Holesovice was chosen as a pilot area in collaboration with IPR Prague. Studied scenarios included changes of housing development as well as assessment of different types of plant canopy and sensitivity studies of the colour of walls, roofs, streets and pavements.
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Development and validation of the new model of thermal conditions of urban environment in fine resolution
Resler, Jaroslav ; Krč, Pavel ; Belda, Michal ; Juruš, Pavel ; Benešová, N. ; Lopata, J. ; Vlček, O. ; Damašková, D. ; Eben, Kryštof ; Derbek, P. ; Maronga, P. ; Kanani-Sühring, F.
The assessment of different scenarios of the city development to air quality and thermal comfort in the areas of street canyons was our main goal inside the project UrbanAdapt. It follows the need for a model which allows to simulate air flows in fine resolution of the order of meter and realistically predict turbulence in the complex terrain of streets and buildings. The LES models comply with such requirements but the review showed that there was no free available LES model which could model the energy exchange in urban environment, i.e. the interaction of energy and air flows including effects of vegetation and different properties of urban surfaces and materials. Thus we decided to extend the existing LES model PALM by a new module USM (Urban Surface Model) which describes the most important energy exchanges in the urban environment. The validation of the model was done against observations obtained by IR camera in the course of heat wave episode in July 2015.
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Monitoring the coefficient of light scattering on aerosol particles at the Kosetice background station
Holubová Šmejkalová, Adéla ; Zíková, Naděžda ; Ždímal, Vladimír ; Holoubek, Ivan
The direct effect of the atmospheric aerosols to radiation balance is the scattering or absorption of light on these particles. While solar radiation on aerosol particles or clouds negatively affects the radiation (resulting in cooling), absorbtion causes increasing of the ambient air temperature. Contribution to the study of the effect of aerosol particles on the climate, a measurement of the coefficient of light scattering is carry out at the Kosetice background station. The Integrating Nefelometer measures at 3-wavelength (RGB) forward and back light scattering. The values of the scattering coefficient at 550 nm (green) are typically high in the cold part of the year, reflecting both increased concentrations of pollutants and stable atmospheric conditions. Daily variability is the smallest in summer (varies between 25 and 18 Mm-1), the most noticeable daily variation is observed in the spring, when stable values 44 Mm-1 drop after noon to 26 Mm-1. The calculation of Ångström's exponent showed that in the summer, the fine fraction dominates in the sampled air.
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Highly time resolved measurement of atmospheric elemental and organic carbon at a typical background site in Central Europe.
Mbengue, Saliou ; Fusek, M. ; Schwarz, Jaroslav ; Holoubek, Ivan
Atmospheric organic (OC) and elemental (EC) carbon play an important role in atmospheric chemistry, climate change and public health. There have been relatively few studies dealing with EC and OC in rural background sites which are less influenced by urban and industrial emissions. Nevertheless, measurements at background areas are important for understanding the transport and transformation characteristics of anthropogenic air pollutants, and their effects on various aspects of regional and global environment changes. In this study, we focus on variability of EC and OC concentrations (considering various day categories and seasons) from a rural background site which is representative for Central European rural areas.\n
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Seasonal Differences in Volatility of Atmospheric Aerosol at a rural measurement site Košetice.
Kubelová, Lucie ; Vodička, Petr ; Makeš, Otakar ; Zíková, Naděžda ; Ondráček, Jakub ; Schwarz, Jaroslav ; Ždímal, Vladimír
Volatility is an important characteristics of atmospheric aerosol because it affects formation, conversion and removal of aerosol particles. This study deals with differences in volatility of atmospheric aerosol at rural measurement site Košetice. Analyzes are based on high-time measurements of atmospheric aerosol, including an aerosol mass spectrometer and a scanning mobility particle sizer. Not only the time variation of mass concentration, but also the daily course of pollutants and the influence of meteorological conditions are discussed.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_22317041913181 - PDF
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