Influence of geographical factors on thermal stress in northern Carpathians.

While general features of mountain climate are well recognised, there is not many research regarded their bioclimatic differentiation. The aim of the present study is to answer the question how different geographical factors: elevation above sea level, physiographical type of area, climate continentality and location of area in relation to the main mountain ridge influence thermal stress in northern Carpathians. To analyse thermal stress in the region, daily meteorological data from 21 stations of national weather networks of Poland, Ukraine and Slovakia for the period 1986-2015 were used. Daily data of air temperature, relative humidity, total cloud cover and wind speed at 10 m above ground for 12 UTC were used because they represent midday hours which are mostly used for any human activity. The Universal Thermal Climate Index (UTCI) was applied as a measure of thermal stress. The results show that (1) cold stress significantly increases and heat stress decreases due to rise of altitude, (2) due to climate continentality and physiographical differences between western and eastern parts of northern Carpathians in their eastern edge, the cold stress is more evident than in western one, (3) at southward slopes of Carpathian, heat stress is significantly more frequent then at northward areas.