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Katarzyna Suwała

Hail occurrence in Poland

The main objective of this study was to present the spatial and temporal distribution of hail in Poland covering the period of 1973-2009. The analysis was based on the data for 23 meteorological stations published by The Institute of Meteorology and Water Management (1973-1980) and National Climatic Data Center (for the years 1981 to 2009). The results are presented with the maps of mean monthly and annual number of hail days, histograms of the seasonal variation of hail and trend lines in temporal variability of hail. It shows that in Poland the mean annual number of hail days varies from 1,3 near Suwałki to 10 near Hel. Most of the hail cases occurred in March, when the number of mean monthly hail days amounted almost 15. When it comes to temporal variability it is characterized by increasing tendency with the maximum at the beginning of 2000.

Open access

Katarzyna Suwała and Ewa Bednorz

Abstract

Taking into consideration the spatial variability of the occurrence of hail in central Europe in the warm season (April - September) during the years 1966-2010, five hail regions were distinguished by Ward’s group hierarchy method. For this purpose the daily data of hail occurrence were used. Circulation patterns responsible for hail precipitation at each cluster of stations were analysed using Reanalysis data (NCEP/NCAR). Composite maps of the sea-level pressure, 500 hPa geopotential height and 850 hPa-level temperature means were constructed for the days with hail. Additionally, anomalies of the values of each parameter were presented. It was found that more than 65% of hail events were recorded from April to June, with May as the hail-peak month. In all five distinguished regions hail precipitation was associated with negative anomalies of SLP and 500 hPa heights over Europe, most often with low-pressure systems developing within colder than usual air mass.

Open access

Mateusz Taszarek and Katarzyna Suwała

Abstract

This report analyses significant hailstorms that occurred in Poland during 2012. The number of reports, derived from the European Severe Weather Database with the hail diameter over or equal 2 cm, were analyzed with respect to their frequency in individual months, time of the day, intensity and spatial distribution. Analyzed cases were divided for hail with diameter less than 4 cm and greater or equal 4 cm. Accompanying conditions were examined by synoptic analysis charts derived from Deutscher Wetterdienst. The total number of 121 large hail cases gave 26 days with this phenomenon. The period of their occurrence extended from April to August reaching peak in July. Above 60% of all events were reported between 1500 and 1800 UTC. Most of them were associated with cold front and squall line features, usually with the south-western warm and moist air mass influx.

Open access

Karolina Rybka, Katarzyna Suwała, Paulina Maziarz and Jakub Matusik

Abstract

In this work, kaolinite modified with zero-valent iron was synthesized and used as a sorbent for Pb(II) and Mo(VI) removal from aqueous solutions. The obtained material was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The methods revealed successful modification by the Fe0 particles precipitation on the surface of well-ordered kaolinite. The sorption experiment results showed a significant increase of sorption capacity in relation to the raw kaolinite. The kaolinite with 25% content of Fe0 was found to be the best material for Pb(II) and Mo(VI) removal, resulting in approximately 500 mmol·kg−1 and 350 mmol·kg−1 sorption, respectively. The possible mechanisms responsible for metals’ removal were identified as reduction by Fe0 ‘core’ and adsorption on the iron hydroxides ‘shell’. The study indicated that the obtained material is capable of efficient Pb(II) and Mo(VI) removal and may be an interesting alternative to other methods used for heavy metals’ removal.