Zmienność dobowa warunków biotermicznych w Polsce w różnych masach powietrza w okresie letnim i zimowym (1991-2000) na podstawie wskaźnika fi zjologicznej temperatury odczuwalnej odczuwalnej

Abstract

The infuence of air masses on thermal conditions varies between seasons. This is also true in case of biothermal conditions. The purpose of this paper is to evaluate daily cyclic behaviour of biothermal conditions in di erent air masses in Poland using direct comparison data for summer and winter seasons. The analysis uses data from six geographically dispersed stations; Koszalin, Białystok, Poznań, Warszawa, Wrocław, and Rzeszów. The data was gathered in time frames covering calendar summers and winters from 1991 to 2000. Based on air temperature, dew point, cloud cover and wind speed physiological subjective temperature (PST, ºC) was calculated. Next, days with particular air masses were chosen and the PST averaged. The index was calculated in BioKlima ver. 2.5. Air masses were divided into four groups: arctic air (PA), maritime polar air (PPm), continental polar air (PPk) and tropical air (PZ). Data was only included where air mass remained consistent over a 24 hour period. The analysis contains evaluation of daily cycle of Physiological Subjective Temperature, the frequency of occurrence of thermal sensations in di erent air masses and appearance of minimal and maximal values of the index. The chosen cities enabled us to research the spatial range of daily variability of the biothermal conditions in Poland. The analysis show that there is a domination of the cold sensations at night hours during summer in all air masses. Day hours were more variable. The cool sensations are dominant in arctic masses. The comfortable conditions occurred in polar maritime masses however in the northern part of Poland this kind of masses cause cool conditions, whereas in the southern warm conditions. Polar continental and tropical masses are the warmest and they cause hot sensations, and in the southern part of Poland very hot sensations. There were very cold sensations in arctic and polar continental air masses at night hours during winter. The other masses in the same period caused cold sensations. There is domination of cold sensations during day hours in all types of air masses and cool sensations occurs occasionally,