Vol. 123, No. 3 * Pages 265–408 * July - September 2019

The effect of the amount and application date of nitrogen fertilizer on maize productivity and profitability was examined in a field experiment established on calcareous chernozem soil at the University of Debrecen in Hungary (47^o 33’ N, 21^o 26’ E, 111 m) under different environmental conditions in the wet crop year of 2016 and the average crop year of 2017. In addition to the non-fertilized treatment, N fertilizer doses were applied in the form of basal and top dressing. The 60 and 120 kg N ha^-1 treatments applied as spring basal dressing were followed by two occasions of 30 kg N ha^-1 top dressing at the V6 and V12 phenophases each. The longer maturity hybrid Armagnac (FAO 490) had a better conversion ratio concerning the precipitation during the growing season of 2016 (which was higher than the 30-year average), as well as the basal and top dressing (averaged over the different treatments) in comparison with the shorter maturity hybrid Renfor (FAO 320). In the wet crop year, the yield of Armagnac was 21.7% higher, while that of Renfor was 10.4% higher. The 60 kg N ha^-1 basal dressing and the +30 kg N ha^-1 top dressing at the V6 phenophase (V6₉₀) resulted in more efficient uptake and better conversion rate in the rainy crop year (2016) in the case of both examined hybrids. In the average crop year (2017), a difference was observed in the successfulness of top dressing. In the case of the Armagnac hybrid (FAO 490), top dressing did not cause any significant yield surplus and the 120 kg N ha^-1 basal dressing was shown to be successful. In the case of the Renfor hybrid (FAO 320), the early top dressing (V6₁₅₀) applied on the basal dressing of 120 kg N ha^-1 was favorable. The most favorable income of nutrient management (N) was provided by the basal dressing of 120 kg N ha^-1 and the +30 kg N ha^-1 (V6₁₅₀) top dressing applied at the early V6 phenophase, averaged over the examined hybrids and years. In the case of the Renfor hybrid (FAO 320), the highest profitability was reached with the V6₁₅₀ treatment, independently of the prevailing environmental factors. However, as regards the Armagnac (FAO 490) hybrid, the top dressing applied at the V12 phenophase provided the highest profitability, which could be achieved with the lowest dose of V12₁₂₀ treatment in the wet year (2016) and the highest dose of V12₁₈₀ in the average crop year (2017). Altogether, based on the results of yield and marginal revenue analysis, the recommended fertilization technology is basal dressing of 120 kg N ha^-1 and basal dressing of +30 kg N ha^-1 (V6₁₅₀) applied at the early V6 phenophase. The obtained findings also show that the effect of N is greatly affected by crop year, genotype, and other elements of the applied technology. Also, marginal efficiency has to be defined for each hybrid, considering the given crop year, too.

Microclimatic analysis of an urban scenario has always been an interesting but complicated challenge. The available remote sensing equipments ensure multi- or hyperspectral imagery being ready to extract excellent land cover information, but the obtained data have lower spatial resolution limiting the efficiency of such analyses. In order to increase the geometric resolution in microclimatic studies, an exercise was executed with an Unmanned Aerial System. The calibration of the imaging camera on a dedicated test field was followed by the data capture flight over the campus of the Budapest University of Technology and Economics. The evaluation of the acquired images has resulted a point cloud containing millions of points. The high density point cloud was able to be transformed into 3D mesh representation and could be fed into a geographic information system for further analysis steps. Based on the color and height information of all individual points, the obtained geometric base was easily to be converted into land cover model representing man-made and natural objects, like buildings or trees. The segmentation of the model is a suitable input for climatic analyses and simulation software packages, where extreme high geometric resolution is required.

Weather conditions have both direct and indirect effects on road traffic. On the one hand, precipitation heavily influences road traction as well as vehicle visibility, and on the other hand, medical meteorology phenomena – for example weather fronts – have a great effect on the driving ability and accuracy of drivers. Weather fronts – through their physiological effects – may cause the deterioration of human reaction times, and therefore increase the risk of accidents’ occurrence in unexpected and hazardous traffic situations that would require quick intervention of drivers. In this article, our research regarding the relation between weather fronts and traffic accidents as well as between local meteorological parameters and weather fronts is presented.
In this article, a crowdsourcing-based methodology is presented, that is supported by a database, which is assembled using data that is far more heterogeneous with regard to acquisition frequency and quality, than those available previously. Using such a database, a driver aiding system can be created for use in cars currently supporting lower levels of autonomy. Such driver assistance systems would be capable of informing or, in a given situation, indirectly decrease the likelihood of the development of an emergency by warning the driver.

Long-distance running is one of the most popular daily sports, through which we can keep our health or take care of our body. Millions of people around the world run for different reasons like recreation, professionalism, mental balance, or fun. That is why long-distance running competitions are organized very often. The organizers have to know the expected meteorological conditions and several specific parameters and information about performance of the runners retroactively to support them effectively as well as adapting to the running attitude and main goals.
The purpose of this study was on one side to develop a data analyzing tool with flexible and multifunctional analytical capabilities to identify which specific – especially meteorological – attributes of long-distance running competitions have relevant impact on the performance of the competitors, while on the other side to compare competitions with each other, which have different environmental and social properties in terms of running pace and age.

This research analyses the daily average wind speed time series of ten Transcarpathian meteorological stations in the period from 2011 to 2015 with the help of statistical methods. We approximated the empirical frequency distribution of measured daily average wind speeds by means of theoretical distributions. The results of the fitting test showed that among the applied theoretical distributions, irrespective of orographic conditions, the Weibull distribution is proved to be the most suitable. However, fitting the Weibull distribution depends on the methods of determining parameters k and c. By means of the best fitting parameters, the distribution density function and some of its indices at the altitude of 80 m were worked out contrary to the anemometer altitude that is often the hub height of industrial wind turbines, thus estimating the wind conditions of the area from wind energy utilization point of view.

This study analyzes the potential changes of residential heating and cooling degree days (HDD and CDD) in the 21st century over Serbia with the regional climate model (RCM) EBU-POM under two different forcing scenarios (A1B and A2). The validation of the model shows that the model reproduces the spatial variability, magnitude, and annual cycles of HDD and CDD for the reference period very well. According to both scenarios, a significant decrease of HDD and increase of CDD is expected all over Serbia. The simulations show a spatial heterogeneity in the potential changes, with the largest decrease of HDD in southern (mountainous) Serbia and largest increase of CDD in northern (lowland) Serbia. Results also show that by the end of the 21st century, the existing ratio between populations weighted regional mean CDD and HDD of 1:7.3 could be reduced to 1:2.3 according to the A1B scenario and 1:2.0 according to the A2 scenario. At the end of the 21st century cooling season length will be for about two times longer than at the reference period, while length of the heating season will be reduced for about 25%. According to both scenarios model projected an increase of the heating and cooling season temperature through 21st century by slightly less than 2 °C. Our study is the first research of future changes in HDD and CDD over Serbia based on regional climate modeling. Results of the research should help the policy of energy management and planning through provided indications of future spatial and seasonal changes of HDD and CDD within Serbia.

In this study, the Weather Research and Forecasting (WRF) model was applied to examine the spatial and temporal formation of urban heat island (UHI) phenomenon in Szeged, Hungary. In order to achieve a more accurate representation of complex urban surface properties in WRF, a modified static database (consists of land use and urban canopy parameters) had been developed using satellite images and building information. In the new database, the number of urban grids increased by 76% related to the default case. The urban landscape in WRF has become more complex after employing two urban land use classes instead of only one. The modification of the default parameters of a single layer urban scheme (i.e., Single Layer Urban Canopy Model – SLUCM) revealed that urban fractions decreased in all urban categories, while street widths increased resulting in narrower urban canyons. For testing the impact of the modifications on near-surface temperature estimation, a four-day heatwave period was selected from 2015. The model outputs had been evaluated against the observations of the local urban climate monitoring system (UCMS). WRF with the modified parameters simulated most of the features of UHI reasonably well. In most cases, biases with the simulations of the adjusted static database tended to be significantly lower than with the default parameters. Additionally, we picked out a longer time period (i.e., the summer of 2015) when the extreme values of near-surface air temperature and maxima of UHI intensities were evaluated on the basis of an urban and a rural site of UCMS. It was concluded that the maxima and minima of observed near-surface air temperature were underestimated (overestimated) by about 1–3 °C at the urban (rural) site. The maxima of UHI intensities indicated cold biases on 86 of 91 days.

The purpose of the study was to determine the anomalous length of growing seasons, the frequency of their occurrence, and to determine the temporal and spatial changes of their frequency in Poland in the period 1966–2015. The analyses used daily average air temperature values for 30 stations located in Poland from years 1966–2015 (Fig. 1). The data was provided by the Institute of Meteorology and Water Management - National Research Institute. The growing season was defined as the period with average daily air temperature ≥5 °C. The start and end dates of the growing season were determined using the mathematical formulas proposed by R. Gumiński (1948). In the period 1966–2015 in Poland, anomalously short growing seasons occurred sporadically and covered the largest area of Poland in 1997. Short growing seasons were more frequent in the first three decades of the analyzed multi-year period, and long growing seasons were characterized by higher frequency in the second half of the surveyed period. Anomalously long growing seasons before 1990 occurred sporadically and only in individual stations. Anomalously short growing seasons occurred only in the middle eastern part of Poland, while anomalously long ones covered most of the country.