Text by: Lobanov V.A.1, Grigorjeva A.A.2, Goroshkova N.I.3
1Russian State Hydrometeorological University, St.Petersburg, 2Yakutsk Hydrometeorological Department, Yakutsk, 3Russian State Hydrological Institute, St.Petersburg
In the coldest territory of Russia, the Republic of Sakha (Yakutia), the impact of climate change on two main characteristics of the cryosphere is considered: permafrost and ice regime of rivers.
To study the dynamics of permafrost, the average monthly soil temperature at a depth of 3.2 meters was selected for the period of its possible thawing (from April to October) at 29 meteorological stations over a long-term period. As a result of the study, it was found that at some stations the soil temperature increased stepwise in the late 1980s. On the territory of Yakutia, 4 types of cryo-hazard were identified for thawing permafrost in September-October, which corresponds to the transition of soil temperature at a depth of 3.2 m through 0оС. A map of cryogenic hazard zones is shown in Fig. 1, where the numbers: 1 – soil temperature was always positive (no permafrost); 2 – the soil temperature has passed the 0оС mark (cryo-hazard zone); 3 – there is a tendency for the temperature to rise, but the 0оC mark has not yet been reached (a possible cryo-hazard zone in the future); 4 – there was no excess of 0оС and is not expected (stable permafrost).
Тable 1 Climatic changes in the main characteristics of river ice formation (Δ is a shift in days)