# Spatio-Temporal Variability of Water Temperature of Arctic Rivers in Russia over the Past 60 Years
## 3 Results
### Current River Water Temperature

Table 7: _Cont._  
Figure 6: Average monthly stream water temperature [\({}^{\circ}\)C] from the change point year to 2021 (based on data from 286 hydrological gauges) in June (**top**) and September (**bottom**). varies from year to year mainly in the range of 2-5 K. The largest amplitude of water temperature occurs in July in the European part of the study area and also in May, June, and October. The lowest amplitude is found in August and September. In the Siberian part of the Russian Arctic, the amplitude is largest in June and smallest in May and October (thawing/freezing transitions, respectively). The average long-term amplitude of river water temperature in the months from May to October practically does not depend on the catchment area of the river. The standard deviation of mean monthly water temperature is on average 0.3-0.5 K. The magnitude of changes in river water temperature after change point years in the overwhelming majority of cases is greater than the indicated values of natural variability (Table 8). The results of the calculations of water temperature changes relative to 1990 differ from those relative to change point years within 0.1-0.2 K in some areas of the European part of the Russian Arctic in May and June. This may be partially due to statistical errors of calculations associated with the length of the series. The changes in water temperature have been shown to be relatively small. However, considering the relatively low temperature of the water, the magnitude of these changes in hydrographic regions can be as high as 20-40%, particularly in May, June, and October (see Table 9). \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Region** & **Month** & **May** & **June** & **July** & **August** & **September** & **October** \\ \hline Northeast & 0.5 & 0.0 & 0.3 & 0.3 & 1.0 & 0.3 \\ \hline Lena & 0.7 & 1.6 & 0.6 & 0.6 & 0.6 & 0.1 \\ \hline Yenisei & 0.7 & 2.1 & 0.7 & 0.5 & 0.9 & 0.8 \\ \hline North of the West Siberia & 1.0 & 2.5 & 0.2 & 0.6 & 0.8 & 0.7 \\ \hline North of the European part of Russia & 1.2 & 1.3 & 0.7 & 0.5 & 1.0 & 1.0 \\ \hline Karelia & 2.2 & 1.2 & 1.3 & 0.6 & 1.5 & 1.5 \\ \hline Kola Peninsula & 1.5 & 1.5 & 1.3 & 1.0 & 1.5 & 0.9 \\ \hline \end{tabular}
\end{table} 
Table 8: Mean statistically significant (relative to the Buishand change point year at \(\alpha\) = 0.05) change in water temperature in rivers [K]) of hydrographic regions of the Russian Arctic (based on data from 286 hydrological gauges) in warm (ice-free) months of the year. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Region** & **Month** & **May** & **June** & **July** & **August** & **September** & **October** \\ \hline Northeast & 42 & 0 & 3 & 3 & 19 & 38 \\ \hline Lena & 41 & 14 & 4 & 4 & 9 & 17 \\ \hline Yenisei & 37 & 21 & 4 & 4 & 11 & 42 \\ \hline North of the West Siberia & 38 & 22 & 1 & 4 & 10 & 37 \\ \hline North of the European part of Russia & 24 & 10 & 4 & 3 & 11 & 30 \\ \hline Karelia & 32 & 8 & 7 & 4 & 14 & 32 \\ \hline Kola Peninsula & 39 & 14 & 8 & 7 & 16 & 27 \\ \hline \end{tabular}
\end{table} 
Table 9: The average percentage of changes in water temperature after a change point year of hydrographic regions of the Russian Arctic (based on data from 286 hydrological gauges) in warm (ice-free) months of the year.