National Repository of Grey Literature 57 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Dependence of activated aerosol on horizontal hydrometeor type.
Zíková, Naděžda ; Pokorná, Petra ; Pešice, Petr ; Sedlák, Pavel ; Ždímal, Vladimír
Atmospheric aerosol (AA) affects not only cloud formation, but also other cloud properties such as droplet size distribution, chemical composition, etc. The interaction between AA and cloud does not have to be investigated only by aerial measurements, but the same processes can be observed in fog and low clouds. An example of a station suitable for such research is Milešovka station, where the fog (or low clouds) is 55% of the time. Here, measurements were made to describe the effect of fog on the number size distributions of AA and activated nucleation nuclei.
Application of Cross-Section Filtration to Detect and Correct Errors Caused by Technical Problems in SMPS.
Wagner, Zdeněk ; Kovanic, P. ; Zíková, Naděžda ; Ondráček, Jakub ; Schwarz, Jaroslav ; Ždímal, Vladimír
The aim of the work is thus development of a robust algorithm for detection of such errors and their fully automatic correction. The algorithm should be fast so that it could be applied in real time.
Comparison of Winter Biomass Burning Source Contribution at National Atmospheric Observatory Košetice Based on AMS and Aethalometer Data.
Schwarz, Jaroslav ; Vodička, Petr ; Zíková, Naděžda ; Mbengue, Saliou ; Šerfözö, Norbert ; Pokorná, Petra ; Makeš, Otakar ; Ždímal, Vladimír
Although atmospheric aerosol concentrations exhibit decreasing trend in last decades, the contribution of aerosol emitted by biomass combustion is opposite due to increasing wood combustion used for residential heating. Previous works determined that the share of aerosol of biomass burning origin was up to 50 % in winter. In this work, the data from aerosol mass spectrometer (AMS) and Positive Matrix Factorization (PMF) are used to elucidate biomass combustion aerosol impact at National Atmospheric Observatory Košetice (NAOK) and the results are compared with simple aethalometer model approach.
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Study of Wet Deposition of Atmospheric Aerosol using Horizontal Hydrometeors.
Zíková, Naděžda ; Pokorná, Petra ; Pešice, Petr ; Sedlák, Pavel ; Ždímal, Vladimír
Processes between atmospheric aerosol (AA) and clouds, source of large uncertainty in weather and climate changes estimations, were described on fogs at Milešovka, meteorological observatory of the Institute of Atmospheric Physics. For the description of the AA properties, online measurement of outdoor particle number size distribution (PNSD) in the size range 10 nm – 20 μm was conducted using SMPS and APS spectrometers. The sampling system consisted of a heated whole air inlet, and PM2.5 sampling head, being switched by an automatic valve. From the difference between PNSD sampled by whole air inlet and by PM2.5 inlet, PNSD of activated particles (aPNSD) was calculated. The aPNSDs differ with hydrometeor type and depend on air mass history, with a stronger influence on freezing fog AA.
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Origin of Atmospheric Aerosol Based on Data with Different Time Resolution at the National Atmospheric Observatory Košetice.
Pokorná, Petra ; Zíková, Naděžda ; Lhotka, Radek ; Vodička, Petr ; Makeš, Otakar ; Mbengue, Saliou ; Holubová Šmejkalová, Adéla ; Schwarz, Jaroslav ; Ondráček, Jakub ; Ždímal, Vladimír
To improve the air quality the underlying causalities must be well understood,particularly when it comes to aspects such as PM concentration, sources and their origin. The aim of this work was to determine air pollution origin at NAOK based on atmospheric aerosol (AA) data of different time resolution measured during intensive summer campaing.
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Identification of Sources of Polycyclic Aromatic Hydrocarbons in Central Europe.
Lhotka, Radek ; Pokorná, Petra ; Zíková, Naděžda
This study evaluates the trends and sources of polycyclic aromatic hydrocarbons (PAH) monitored at National atmospheric observatory Košetice (NAOK), a rural background site. In total, 14 PAH concentrations in particulate matter (PM10) between 2006 and 2016 were evaluated. The highest concentrations of all PAH were measured at the beginning of the study period, in 2006. The positive matrix factorization (EPA PMF 5.0) was used to determine the sources of PAH at NAOK, with three factors resolved. The probable origin areas of PMF factors were identified by Conditional Bivariate Probability Function method (CBPF) and Potential Source Contribution Function method (PSCF) methods. NAOK is affected by local sources of PAH, as well as by regional and long-range transport.
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Changes in snowpack in the czech mountains during the last 50 years
Zuzáková, Eliška ; Pokorná, Lucie (advisor) ; Zíková, Naděžda (referee)
This work focuses on the progressive development of snow cover in the last fifty years in Krkonoše, Jizerské mountains and Šumava regions. According to scientific papers and studies, a decrease of snow or snow precipitation is observed on some areas. Snow is an essential part of the natural hydrological cycle and the climate system. The review is focused on the climate changes in the Czech republic, snow and its characteristics. The practical part containes an analysis of the meteorological data from selected stations and the discussion of the snow cover changes during the period 1964-2014. Key words: Czech republic, number of days with snow cover, snow depth

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