ИСТИНА

Urban heat island (UHI) effect is well studied for moderate and low latitudes and is considered in general as a negative phenomenon due to its influence on human thermal comfort and energy consumption rates. For the Arctic, on the contrary, its positive effects could be related with mitigation of severe frosts and fuel economy for house heating. However, until nowadays the knowledge about polar UHIs was extremely poor and limited by few studies for Alaskan towns, while the biggest Arctic cities located in Russian sector of Northern Eurasia were the terra incognita for urban climatology. In this study we present the first quasi-climatological estimates of UHI intensity (urban-rural temperature difference) for Arctic winter conditions. They are based on UHIARC (Urban Heat Island Arctic Research Campaign) seasonal-scale experimental meteorological observations in five medium-sized Russian Arctic cities (Apatity, Vorkuta, Nadym, Novy Urengoy, Salekhard). Measurements in these cities have shown quite similar values of UHI intensity and patterns of its temporal variation. For all of them the average winter UHI intensity could be estimated as 1-1.5 °C, while extremes up to 6-7 °C are observed in frosty anticyclonic weather. However, the Arctic UHIs could be strongly amplified by local orography. For Apatity this results in extremely high (up to 12 °C) values of temperature differences between the city, located at the top of the hill, and WMO weather station at the lowland.