Spatio-Temporal Variability of Water Temperature of Arctic Rivers in Russia over the Past 60 Years

This article presents the findings of a comprehensive statistical analysis based on one of the largest and most up-to-date datasets on average monthly water temperatures at 286 hydrological stations from 1961 to 2021. Through this analysis, a detailed examination of the factors influencing temperature formation in different landscape-diverse regions in the Russian Arctic has been conducted. It has been determined that air temperature plays a crucial role in determining water temperature, although its influence is constrained by geographical factors, primarily geographical latitude. An analysis of discontinuities in uniformity and the presence of trends was carried out, along with a regression analysis of the relationships between air and water temperatures. The results of estimating changes in river water temperature were simultaneously compared both with respect to generally accepted climatic periods (1961–1990 and 1991–2020) and with respect to revealed change point years. The results of the statistical analysis indicate a relatively slow increase in water temperature in the Arctic rivers of Russia over the past 60 years, by 0.11–0.74 K/decade. These changes are mainly due to changes in air temperature (about 70% of cases), which in turn are influenced by the altitude of the location of the objects and other local factors.