ИСТИНА

Overall impact of climatic conditions on human can be estimated using bioclimatic indexes. We used UTCI index to estimate bioclimate for the Russian Arctic. Initiated by Commission of the International Society of Biometeorology, and developed with support from the European Union within the COST Action 730, the Universal Thermal Climate Index (UTCI) aims at the assessment of the outdoor thermal conditions in the major fields of human biometeorology. Index UTCI can be described as an equivalent environment temperature (° C) which provides the same physiological impact on human as the actual environment. This feature allows to use UTCI throughout the Russian territory. Seasonal fluctuations of UTCI index and changes of distribution of discomfort levels during the climate change were shown for the Russian Arctic territory. Cold stress conditions (from moderate to extreme) were observed in the Russia Arctic for about 8–11 months a year. Extreme cold stress was observed in the latitudinal zone of 70–80°N for 5 months in European Russia and for 6 months in West Siberia. In the latitudinal zone of 60–70°N it was observed for 1.5 months in western Siberia and for 2 months in the Far East and on the Chukchi Peninsula. At the beginning of the 21st century the duration of extreme cold stress reduced by 1.5–2 months in the east and by 3 months in European Russia. Very strong cold stress was observed for 2–3 months at 70–80° N and for 2–4 months at 60–70° N. During the rest part of the year conditions are neutral or there is slight cold stress. The period of extreme and very high cold stress decreases during the modern climate warming, especially in Arctic, in the north of European part of Russia, in the western and central Siberia. At the same time, the period with neutral and slight cold stress conditions enhances.