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This paper presents eddy covariance measurements of evapotranspiration and sensible heat flux in wetland area. The rate of evapotranspiration is characterized by a distinct seasonal pattern and assumes the highest values during summer. From April to September, the latent heat flux is characterized by a distinct diurnal pattern with the highest average values (at the noon hours) at a level of ca 200 W·m during the winter months to about 3-3.5 mm·d −1 in summer.

It is shown that if the computer model of biological ageing proposed by Stauffer is modified such that the late reproduction is privileged then the Gompertz law of exponential increase of mortality can be retrieved.

The COVID-19 pandemic caused a sudden and deep recession contributing, among other things, to a sharp rise in unemployment. The article addresses changes in the labor markets of the Visegrad countries (Czechia, Hungary, Poland, and Slovakia), covering the period 2018–2021. It attempts to answer the questions: how deep a slump was caused by the pandemic in these markets, how flexible forms of employment responded to it, and whether there were discriminatory phenomena (decline in employment and increase in unemployment in the most vulnerable groups in the labor market). The analysis was based on quarterly data published by Eurostat on the size and structure of the employed and unemployed population. The results of the compilations indicate a relatively small deepening of imbalances in the labor markets of the analyzed countries, a differentiated reaction of flexible forms of employment (depending on the form of employment), which was in line with expectations (they were used as a business cycle buffer). In most of the V4 countries, women were relatively less likely to lose their jobs than men during the pandemic. In a few cases, a relatively stronger decline in employment (increase in unemployment) affected young people, people aged 55–64, and people with the lowest education.

In the recent years, an economic crisis has appeared in most economies. It affected the labor market situation. This article refers to the changes in the labor markets of the Visegrad Group countries. The analysis concerns the relations between the economic crisis, the level and structure of unemployment (taking into account the situation of women and young people as the groups strongly exposed to unemployment), and the level and structure of expenditures within the labor market policy. The article is based on the data published by Eurostat, using the tools of descriptive statistics, and statistical indexes, in particular. The research period covers the years 2007-2012, which is dictated by the availability of comparable statistical data. An analysis of the data indicates that the economic crisis increased the economic activity of the population, which contributed to an increase in unemployment. There is no discrimination against women in the labor market, but there has been a serious increase in unemployment among young people. With the increase in unemployment, the expenditures on the total labor market policy have increased, as have those on passive labor market policies and labor market service. Expenditures on active labor market policies (ALMPs) grow relatively more slowly, which may be especially evident in the case of expenditure on training.

The sensible heat flux (H ) is determined using large-aperture scintillometer (LAS) measurements over a city centre for eight different computation scenarios. The scenarios are based on different approaches of the mean rooftop-level (z H ) estimation for the LAS path. Here, z H is determined separately for wind directions perpendicular (two zones) and parallel (one zone) to the optical beam to reflect the variation in topography and building height on both sides of the LAS path. Two methods of z H estimation are analyzed: (1) average building profiles; (2) weighted-average building height within a 250 m radius from points located every 50 m along the optical beam, or the centre of a certain zone (in the case of a wind direction perpendicular to the path). The sensible heat flux is computed separately using the friction velocity determined with the eddy-covariance method and the iterative procedure. The sensitivity of the sensible heat flux and the extent of the scintillometer source area to different computation scenarios are analyzed. Differences reaching up to 7% between heat fluxes computed with different scenarios were found. The mean rooftop-level estimation method has a smaller influence on the sensible heat flux (−4 to 5%) than the area used for the z H computation (−5 to 7%). For the source-area extent, the discrepancies between respective scenarios reached a similar magnitude. The results demonstrate the value of the approach in which z H is estimated separately for wind directions parallel and perpendicular to the LAS optical beam.

The primary aim of this paper was to present the results of turbulent sensible heat flux (QH) measurements with Scintillometer Scintec BLS900 (LAS). The theoretical background of scintillation method has been presented as well as two different ways of sensible heat flux computation from LAS. The measurements presented here were conducted from April to December 2011. Diurnal and partially annual variability of QH has been analyzed, moreover the mean diurnal course of QH in considered months has been prepared. In order to choose the optimal method of QH computation from LAS the results obtained with three different Monin-Obuchov similarity theory functions as well as free convection assumption has been compared. In first case it has been proved that sensible heat flux differs significantly depending on chosen universal function. In turn in case of free convection assumptions it has been revealed that it is valid only for very unstable conditions. Therefore it does not apply to long-time heat flux measurement in case of Łódź. Nevertheless, this study has shown that scintillation method is valuable and reasonable source of path-averaged QH estimates in considered city.