Temporal Variability of Soil Temperature in the North-West Arctic Zone of Russia. Part I: Interannual Linear Trends Based on Thermometer Measurements and Reanalysis Data

In this article we investigate near-surface air temperature (NSAT) and soil temperature variability at four depths in the region of the White Sea, Murmansk and Arkhangelsk Regions, and Republic of Karelia. For the analysis we used NOAA-CIRES-DOE 20th Century Reanalysis (Version 3) reanalysis data for the 1980–2015 time period and data of bent-stem thermometers at 5, 10, 15, 20 cm depths and extraction thermometers at 20, 60, 80, 120, 240 and 320 cm depths for 1985-2021 time period. Average variability of NSAT is estimated using linear trend as +0.028 ◦C/year. For soil temperature a linear trend is of +0.0137 ◦C/year on surface (0 cm), +0.0136 ◦C/year at 10 cm depth, +0.0142 ◦C/year at 40 cm depth and +0.0133 ◦C/year at 100 cm depth.