National Repository of Grey Literature 40 records found  beginprevious31 - 40  jump to record: Search took 0.01 seconds. 
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
Comparison of Atmospheric Aerosol Volatility at a Rural Site in Central Europe.
Kubelová, Lucie ; Vodička, Petr ; Makeš, Otakar ; Zíková, Naděžda ; Ondráček, Jakub ; Schwarz, Jaroslav ; Ždímal, Vladimír
Volatility is an important characteristic of atmospheric aerosols as it affects their origin, lifetime and removal. Accurate description of aerosol volatilities is important for models calculating condensation of semi-volatile species and it also enables better identification of aerosol sources (Wu et al., 2009). However, our understanding of volatilities of organic atmospheric aerosols and the related processes is still rather poor (Han et al., 2016.
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Plný tet: SKMBT_C22017103113060 - Download fulltextPDF
Seasonal, weekly and diurnal variability of elemental and organic carbon at a rural background site in Central Europe, a four years of measurement
Mbengue, Saliou ; Fusek, M. ; Schwarz, Jaroslav ; Vodička, Petr ; Holubová, Adéla ; Holoubek, Ivan
Atmospheric organic (OC) and elemental (EC) carbon play an important role in\natmospheric chemistry, climate change and public health. There have been relatively\nfew studies dealing with EC and OC in rural background sites which are less influenced\nby urban and industrial emissions. Nevertheless, measurements at background areas are\nimportant for understanding the transport and transformation characteristics of\nanthropogenic air pollutants, and their effects on various aspects of regional and global\nenvironment changes. This work is one of the rare studies using a semi-continuous\nmeasurement technique to focus on long-term (4 years) measurements of EC and OC at\nregional background site in Europe. It focuses on the factors or phenomena influencing\nboth diurnal and weekly variability of EC and OC concentrations during various seasons\nat rural background area.
Transformation of Aerosol Particles during Transport from Outdoor to Indoor Environment.
Ondráček, Jakub ; Talbot, Nicholas ; Kubelová, Lucie ; Makeš, Otakar ; Cusack, Michael ; Schwarz, Jaroslav ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír
One summer (2014) and one winter (2015) campaign (both lasting three weeks) were conducted to assess the indoor/outdoor physical and chemical properties of aerosol in an unoccupied apartment. The main purpose of these campaigns was to observe the changes in aerosol particles before and after their transport from outdoors to indoors. The most important parameter – the I/O ratio was obtained from indoor/outdoor measurements of aerosol number size distribution as well as chemical composition. The I/O ratios can reveal the changes in particle size and physicochemical characteristics indoors in relation to the size distribution and chemical composition outdoors, and physical parameters such as wind speed, temperature, and RH.
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Plný tet: SKMBT_C22017103110370 - Download fulltextPDF
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.
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
PM2.5 Chemical Composition at the Rural Background Site Košetice.
Schwarz, Jaroslav ; Cusack, Michael ; Karban, Jindřich ; Chalupníčková, E. ; Havránek, Vladimír ; Smolík, Jiří ; Ždímal, Vladimír
Measurements of atmospheric aerosols at rural background areas are important because they are not influenced by the urban emissions, and are therefore better suited to investigate the influence of long-range transport and trends in concentrations of individual pollutants. Summary of the measurements of total concentration and the concentration of PM10 and PM2.5 components was carried out in the works Putaud et al. (2004, 2010). Although the later work included the measurement of more than 60 stations across Europe, the post-communist countries contained data on PM2.5 from only four locations (Prague, Debrecen, Hungary, and two rural locations). Although Košetice place where this study was made, is also discussed there, it was for only PM10 and total carbon (TC). Therefore, the aim of this study is to fill this information gap, and provide additional information regarding the PM2.5 fraction and composition at the Central European background station Košetice.
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Plný tet: SKMBT_C22016110313110 - Download fulltextPDF
On Usage of Size Segregated Particle Number Concentration to Guess The Origin of PM2.5 at the Rural Background Site Košetice.
Schwarz, Jaroslav ; Cusack, Michael ; Karban, Jindřich ; Chalupníčková, E. ; Havránek, Vladimír ; Smolík, Jiří ; Ždímal, Vladimír
Rural background studies serve mainly to assess the long-range transport influence and long-term trends. However, it is difficult to find a place with no influence of local sources. This is also the case of Košetice observatory having three small settlements within two km from the observatory. Therefore we attempted to analyze if the influence of these or other nearby sources can be seen in our data on PM2.5 chemical composition. Besides other possibilities like specific ratios of various gaseous compounds we concentrated on using size resolved number concentration data because of their dynamics that leads in general into particle growth until they reach accumulation mode. Several similar studies (e.g. Cusack et al. 2013) were performed during recent years.
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Plný tet: SKMBT_22316102413000 - Download fulltextPDF
Comparison of Atmospheric Aerosol Volatility at a Suburban and Rural Measurement Site.
Kubelová, Lucie ; Vodička, Petr ; Schwarz, Jaroslav ; Makeš, Otakar ; Ždímal, Vladimír
One of the most important characteristics of atmospheric aerosols is their volatility. Volatility affects the formation, life time, and removal of aerosol particles (Huffman et al., 2009). Accurate description of volatility of atmospheric aerosols can lead to a better identification of their sources and it is also crucial for models incorporating condensation and aging of aerosols. However, there is still a lack of knowledge regarding aerosol properties such as volatility especially in case of organic aerosols. To increase our understanding of aerosols volatility, we have performed summer (21.8.-2.10.2012; 17.6.-18.8.2014) and winter (19.2.-28.5.2013; 9.1.-13.3.2014) measurement campaigns with a thermodenuder at a suburban site in Prague Suchdol and at a rural site Košetice, respectively.
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Plný tet: SKMBT_C22016102412230 - Download fulltextPDF
Research Infrastructure ACTRIS-CZ.
Holubová Šmejkalová, A. ; Ždímal, Vladimír ; Váňa, M. ; Klánová, J. ; Dvorská, Alice
Research infrastructure ACTRIS-CZ was adopted on the Czech national roadmap of reaserch infrastructures in 2016. Its coreforms a co-located station Košetice-Křešín u Pacova and special equipment from collaborating partner institutions. Research infrastructure ACTRIS-CZ is focused on atmospheric research, especially on atmospheric aerosol, reactive gases and meteorological parameters.
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Plný tet: SKMBT_C22016111512070 - Download fulltextPDF

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