Przegląd Geograficzny (2018) vol. 90, iss. 1
The diurnal course of air temperature and humidity in Poland in consecutive ten-day periods of the year
Przegląd Geograficzny (2018) vol. 90, iss. 1, pp. 53-75 | 
Full text
doi: https://doi.org/10.7163/PrzG.2018.1.3
Abstract
The purpose of the work detailed here was to reveal the diurnal variability characterising values for air temperature and vapour pressure in Poland. To this end, reference was made to meteorological data – concerning air temperature (°C) and water vapour pressure (hPa) – derived from eight observation terms over the period 1991-2000, and from the Polish cities of Koszalin, Białystok, Poznań, Warsaw, Wrocław and Rzeszów. These data were used to calculate average diurnal values for each of these meteorological elements, with graphs constructed to show the averaged daily courses for air temperature and water vapour pressure, as well as the course of averaged diurnal extreme values and amplitudes in regard to both elements, together with the hours associated with them. All analyses were carried out for consecutive ten-day periods of the year. Because of the uneven changes in the variables throughout the daytime, extreme values for air temperature and water vapour pressure were approximated using an asymmetric function. The diurnal courses to thermal and humidity conditions in the Polish cities under study are found to be characterised by a certain variability, both temporally and spatially. In particular, there are significantly fewer instances of stable weather conditions during the summer season, than in winter. The hours of occurrence of air temperature minima depend on the season. In winter they occur much later, about 5-6 a.m., while in the warm half of the year they are noted at approximately 2 a.m. Diurnal maxima for air temperature appear around the same time of day, usually at about 1 p.m. year-round. Analysis of the spatial structure characterising variability in diurnal air temperature showed SE Poland (Rzeszów) to be the warmest region in summer during daytime hours. Summer nights are hottest in the south-west (Wrocław) and middle part of Poland (Warsaw). In winter, the privileged stations in respect of thermal conditions are Wrocław and Koszalin, during daytime hours and at night respectively. The diurnal course sees water vapour pressure rise during the hours of daytime, and decrease at night. In turn, annual variability is characterised by significant summer increases and winter decreases. In the summer, the diurnal courses for water vapour pressure are characterised by the presence of two minima and two maxima per day. The first diurnal minimum is usually recorded in the morning, between 2 a.m. and 6 a.m., albeit slightly later in winter, while the second, appearing in the warm season, is observed between 12 a.m. and 4 p.m. In the case of the diurnal maximum, the first, is more seasonally dependent than the minimum, in that it occurs between noon and 4 p.m. in winter, most often around 8 a.m. A second one is noted between 4 and 8 p.m. The spatial range of occurrence of different values for water vapour pressure points to a rise in the western part of the country in the cool half of the year, while south-eastern Poland is more privileged in this regard in the summer.
Keywords: przebieg dobowy, temperatura powietrza, ciśnienie pary wodnej, Polska
[monika.okoniewska@ukw.edu.pl], Uniwersytet Kazimierza Wielkiego w Bydgoszczy, Instytut Geografii
Citation
APA: Okoniewska, M. (2018). Dobowy przebieg temperatury i wilgotności powietrza w Polsce w kolejnych dekadach roku. Przegląd Geograficzny, 90(1), 53-75. https://doi.org/10.7163/PrzG.2018.1.3
MLA: Okoniewska, Monika. "Dobowy przebieg temperatury i wilgotności powietrza w Polsce w kolejnych dekadach roku". Przegląd Geograficzny, vol. 90, no. 1, 2018, pp. 53-75. https://doi.org/10.7163/PrzG.2018.1.3
Chicago: Okoniewska, Monika. "Dobowy przebieg temperatury i wilgotności powietrza w Polsce w kolejnych dekadach roku". Przegląd Geograficzny 90, no. 1 (2018): 53-75. https://doi.org/10.7163/PrzG.2018.1.3
Harvard: Okoniewska, M. 2018. "Dobowy przebieg temperatury i wilgotności powietrza w Polsce w kolejnych dekadach roku". Przegląd Geograficzny, vol. 90, no. 1, pp. 53-75. https://doi.org/10.7163/PrzG.2018.1.3