## 4 Discussion
This is the southwestern wind within all the studied area. Between the 1980-1999 and 2000-2021 periods, the wind speed has increased in some areas by 0.10-0.15 m/s, which is 10% of the average values. There is a significant seasonal variability in wind speed, which changes on average from 1 m/s in summer (June-August) to 2-3 m/s in winter (December-February). In some months and in some areas, the observed changes are even more significant. For example, between the periods 1980-1999 and 2000-2021, in March, the wind speed increased by 0.5 m/s along the railway to Yamburg. In April, the same wind speed increase was observed on the same railway to Salekhard and on the Murmansk railway. In June, the same wind speed increase was observed in the vast area around Syktyvkar. In July, the wind speed increased by 0.5-1.0 m/s near Salekhard and Yamburg. In August, the wind speed increased by 0.5 m/s in Karelia, at the railway sections to Salekhard and Yamburg, and in September by 0.5 m/s everywhere in Figure 27. In the central part of the studied area, the wind speed growth rate in the last 20 years reached 0.1 m/s per 10 years, which is about 10% per decade in Figure 28.  
Figure 23: Average rate of change (linear trend) of mean monthly anomalies (relative to the annual rate) of air temperature at 2 m altitude (\({}^{\circ}\)C per 10 years) for 1980–1999. Figure 22.0 Average rate of change (linear trend) of mean monthly anomalies (relative to the annual rate) of air temperature at 2 m altitude (\({}^{\circ}\)C per 10 years) for 2000–2021. Figure 22.1 Average changes (difference in average values) in total precipitation per day (in) between the periods 1980–1999 and 2000–2021. Figure 22.2 Average wind speed change (m/s) (difference of average values) at 50 m altitude between the periods 1980–1999 and 2000–2021 for September. Figure 22.3 Average rate (linear trend) of change in mean monthly anomalies (relative to the annual rate) of total precipitation per day (in/day per 10 years) over 2000–2021. In the last two decades, the average snow cover thickness in the studied area was 20-35 cm in Figure 22.4 The observed climate warming led to a decrease in snow cover thickness from 1980-1999 to 2000-2021 by 2-4 cm in the western and eastern parts of this territory, i.e., by approximately 10% in Figure 22.5 The highest snow cover thickness is observed in March, when it reaches 50-80 cm in different regions, and from 70 to 100 cm along the railway from Syktyvkar to Salekhard in Figure 22.6 From June to September, the snow cover is absent. The rate of snow cover reduction can reach 2.5-3.5 cm per 10 years in the northern part of this region, both on the Kola Peninsula and in the area of the Gulf of Ob. Soil temperature increased significantly along with the climate warming [62]. Average changes in temperature of the upper 10 m of soil between the periods 1980-1999 and 2000-2021 varied from 0.2 \({}^{\circ}\)C to 0.8 \({}^{\circ}\)C. This warming affected the area westwards from the Ural Mountains; the area eastwards remained virtually unaffected in Figure 22.7 The spatial distribution of soil temperature in the last two decades is shown in Figure 22.8 Notably, in both average values and in values for individual months, negative values of soil temperature in the MERRA-2 database are observed only on the Novaya Zemlya Archipelago, Yamal Peninsula, and northwards from 68\({}^{\circ}\)N in the territory east of the Gulf of Ob. This distribution contradicts the known maps of the permafrost boundary position in northern Russia and Siberia [3, 6], so this issue requires special consideration. The average rate of soil temperature increased in 2000-2021 and reached from 0.2 \({}^{\circ}\)C to 0.8 \({}^{\circ}\)C per 10 years in the central part of the studied area whereas in the far northern regions it reached from 1.2 \({}^{\circ}\)C to 1.6 \({}^{\circ}\)C per 10 years in Figure 22.9  
Figure 24.0 Average rate (linear trend) of wind speed change at 50 m altitude (m/s per 10 years) for 2000–2021.