Wednesday 26 June 2019
Időjárás - Quarterly Journal of the Hungarian Meteorological Service (OMSZ)

Vol. 123, No. 1 * Pages 1–133 *January - March 2019

Quarterly Journal of the Hungarian Meteorological Service

download [pdf: 3704 KB]
Estimation of rainfall erosivity in Piedmont (Northwestern Italy) by using 10-minute fixed-interval rainfall data
Fiorella Acquaotta, Alice Baronetti, Mario Bentivenga, Simona Fratianni, and Marco Piccarreta
 PDF (1908 KB)   |   Abstract

Rainfall erosivity index (EI30) is widely used in soil erosion models for predicting soil loss. This index consists in the product between the maximum intensity of 30-min rainfall and the total kinetic energy of a precipitation event. The main goal of this study was to characterize the soil erosion in Piedmont (Northwestern Italy), studying the magnitude, frequency, and trends of rainfall erosivity. Rainfall erosivity for twelve stations well distributed over the whole region were firstly computed on the basis of 10-min time-resolution rainfall data using a continuous 17-year series of daily rainfall events. For each station the equation to predict EI30 from daily rainfall data was calculated, and, using the Nash and Sutcliffe (1970) model-efficiency, the relationships between real EI30 and modeled EI30was validated. The rainfall erosivity model was applied to the long term daily rainfall series of the selected stations, to create annual and seasonal erosivity time series for the climate normal period 1986–2015. Afterwards, the Mann–Kendall non-parametric test statistic to detect time trends in the rainfall erosivity time series was applied. The results have led to the conclusion that the annual rainfall erosivity should have experienced mixed trends in most of the study area, although more than half of the stations did not show a statistical trend.

Synoptic-climatological analysis of high level air flow over the Carpathian Basin
Anna Zsilinszki, Zsuzsanna Dezső, Judit Bartholy, and Rita Pongrácz
 PDF (7419 KB)   |   Abstract

In recent years, several unusual (or at least very rare) weather events occurred in the Carpathian Basin, e.g., the severe snow in March 2013. We are assuming that this anomaly may be a part of the climate change-related macro-scale circulation changes, especially the changes in the characteristics of polar jetstream. For evaluating this hypothesis, we performed a detailed statistical analysis of the high level wind fields of the region for 22 vertical layers above the 500 hPa pressure level, including the detailed analysis of average wind speed and wind directions, trend analysis of daily wind speed values, and extreme wind speed values. The results show negative trends in the mean wind speed at the higher tropospheric levels, and positive trends at the very high stratospheric levels in the Carpathian Basin. Furthermore, statistically significant trends mostly occurred in westerly winds, which is the most frequent wind direction.

Dust deposition, microscale flow- and dispersion model of particulate matter, examples from the city center of Budapest
Orsolya Farkas and Ákos Török
 PDF (3846 KB)   |   Abstract

Despite the air quality improvement, air pollution is still a severe problem in Budapest, and the city is one of the most polluted capitals of Europe. Dust has an adverse health effect, and it also causes aesthetic changes to buildings. Dust contributes to the damage of stone and may also result material loss. The paper analyzes the composition of dust and also describe its flow patterns in the city center of Budapest. The study area is located in one of the most polluted areas of Budapest, at Margit Boulevard. Dust samples were collected from the facades of buildings. Samples were analyzed with particle size analysis with laser diffraction, point counting of particles by optical microscopy, and X-Ray Diffraction (XRD). To simulate the airflow and the dispersion of particulate matter (PM10), a computational fluid dynamics code called MISKAM (Mikroskaliges Strömung- und Ausbreitungsmodell - microscale flow and dispersion model for built up areas) was used. The results suggest that dust deposition is controlled by the flow pattern. Analyzed dust samples contain wind driven mineral grains (quartz, dolomite) and also human activity related pollutants such as fly ash and soot.

Thermal conditions in the summer season on the Polish coast of the Baltic Sea in 1966 –2015
Arkadiusz M. Tomczyk, Sebastian Kendzierski, Magdalena Kugiejko, and Natalia Pilguj
 PDF (3239 KB)   |   Abstract

The Baltic Sea coast is characterized by a large frequency of days with biometeorologically adverse effects. In many Polish and foreign studies there are issues related to the increase in the frequency of warm days, hot days, and heat waves. The present study introduces the characteristics of thermal conditions on the Polish coast in the 1966–2015 multiyear period, as well as the identification of circulation conditions favoring the occurrence of extremely warm periods. The analysis included the maximum temperature data (obtained from five measurement stations), on the basis of which the characteristics such as: average maximum air temperature, sum of maximum air temperatures occurring in summer, warm days (Tmax >25 °C), hot days and heat waves (Tmax >30 °C) were determined. The existing thermal classification proposed by Lorenc (2000) was also used in relation to the maximum daily temperature. In addition, there appeared a topic of atmospheric circulation regarding the determination of conditions for the occurrence of exceptionally warm months (mean Tmax >Ts+1.5σ). The research results indicate an increase in the average maximum temperature (Tmax) in the summer season in 1966–2015. The changes are particularly visible in the western part of the research area (0.43 °C/10 years). Furthermore, the observed warming was translated into a higher occurrence of warm and hot days, which was discussed by other authors in the context of the whole of Poland. The occurrence of exceptionally warm months has reached the maximum frequency in the last 15 years, which is associated with positive anomalies of the sea level pressure and the 500 hPa isobaric surface. Periods of occurrence of the above mentioned anomalies were related to the presence of high pressure systems and the advection of air masses from the eastern sector (according to the presented T850 maps).

Investigation of soybean leaf area influenced by water supply
Angela Anda*, Brigitta Simon, Gábor Soós, László Menyhárt, and Tamás Kucserka
 PDF (783 KB)   |   Abstract

Soybean leaf area observations were carried out in two levels of water supply using two different varieties (Sinara and Sigalia) in Hungary. Half of the crops was grown using unlimited watering in evapotranspirometers, while the others received only 50% of their water requirements from the R1 (beginning bloom) stage (stressed crops). Out of four meteorological variables, the air temperature, the most easily accessible meteorological variable impacted the LAI (leaf area index) the most, irrespective of water supply. To obtain the variation in the vertical leaf area distribution, the LAImax was selected and analyzed, when leaf area remained relatively invariable. Water deprivation in the reproductive phase significantly reduced the LAI, irrespective of the studied variety. The water stress condition significantly lowered the level-wise trifoliate area of Sigalia above the sixth leaf level but did not lower it in the case of Sinara. Increase of 1.5 in the number of leaf levels could be contributed to the higher LAI of crops with unlimited watering in comparison to water stressedones. The area of the middle leaflet was significantly higher compared to the outer ones at the bottom and the top of the plant, but they were of about the equal size around the center of the plant height irrespective of the variety. According to our best knowledge, this morphological phenomenon has not been described yet.

Thermal seasons onset and length in Poland – a multiannual perspective on 1971–2010
Michał Kitowski, Michał Marosz, and Mirosław Miętus
 PDF (2533 KB)   |   Abstract

The major aim of the research is to analyze the variability of thermal seasons characteristics (onset and length), at 7 stations in Poland during the 40-year-long period of 1971–2010. The analysis comprised the selection of the optimal method for season onset identification and the statistical analysis of the season onset and length characteristics, which was augmented with the interdecadal comparison of statistics using one-way analysis of variance (ANOVA). Also, it was investigated if the season onset type (late/normal/early) induces the season length distribution characteristics. The results show that the variability of the onset of thermal seasons is most pronounced in the case of summer and early spring. Summer also shows the tendency to occur faster, whereas autumn tends to start later. The interdecadal change of the thermal seasons length is clearly visible in the case of summer which length systematically increases and winter where the trend is reversed at most of the stations. The research also confirmed that for winter, early spring, and summer, the onset type clearly determines the distribution of the season length. Other seasons either show little variability or the differences appear only at some stations.

Predicting future shift of drought tolerance zones of ornamental plants in Hungary
Ákos Bede-Fazekas and Krisztina Szabó
 PDF (1688 KB)   |   Abstract

Climate of Hungary, Central Europe, is predicted to undergo substantial aridification by 2100 due to the decrease of precipitation in the summer season. Dendrology and ornamental plant application require adaptation to these climatic changes. This paper aims at giving guidance for landscape architects, dendrologist, and horticulturists by providing spatial predictions on both drought tolerance zones of ornamental plants and the amount of needed irrigation (i.e., precipitation deficit). Future climate of two prediction periods (2025–2050, 2071–2100) are compared to that of the reference period (1961–1990), based on regional climate model RegCM3 driven by IPCC SRES scenario A1B. Three drought tolerance zones are studied that are found to shift northward in the future. It is predicted that, by the end of the 21st century, the less drought tolerant ornamental plants applied countrywide nowadays will lose the chance to survive without considerable irrigation efforts in Baranya, Bács-Kiskun, and Csongrád counties (southern Hungary). Since nursery production is now located in those regions that may be mostly affected by aridification, it needs planning adaptation measures.

Comparison of regression models of PM10 particulate concentration in relation to selected meteorological elements based on the example of Sosnowiec, Poland
Adam Adamek and Agnieszka Ziernicka-Wojtaszek
 PDF (686 KB)   |   Abstract

The aim of the study was to construct linear regression and multiple regression models, describing the dependence of PM10 particulate concentration in the city of Sosnowiec on selected meteorological elements: air temperature, precipitation and wind speed. Three multiple regression models were constructed: a generic variant without regard to the barometric situation, and two models separately for high-pressure and low-pressure situations. The data used in the study were the average daily concentrations of PM10 registered during the 2013–2015 heating seasons at the Sosnowiec station on Lubelska Street, belonging to the Air Quality Monitoring System operated by the Voivodeship Environmental Protection Inspectorate in Katowice.

IDŐJÁRÁS - Quarterly Journal