Home – Home – Jornals – Geography and Natural Resources 2020 number 2

The permafrost and climate conditions of the Anadyr lowland (Chukotka) for the late 20 ^th - early 21 ^st centuries are ex amined. A statistical estimate is made of the trends for an increase in air temperature and precipitation amounts. We summarized the monitoring results on the layer of seasonal thawing in typical permafrost landscapes of the Anadyr lowland in 100 × 100 m areas within the Circumpolar Active Layer Monitoring (CALM) program. The dynamics of active layer thickness and tempera ture is considered in correlation with weather and climate during 1994-2017. With an increase of the mean long-term values of mean annual air temperature by 1.1 ° C (14 %) and of the annual precipitation amount by 102 mm (31 %), the temperature and precipitation variations reached 17 and 27 %, respectively. This corresponds to a medium and significant degree of disper sion of data. An increase in the length of a warm period of a year was by 4 days (3 %), with a variation of the values making up 7 %. It is pointed out that interannual fluctuations are responsible for short fluctuations (3-5 years) in temperature and thickness of the seasonally thawed layer. An increase in the length of a warm period of a year has influence on long-term changes in seasonal thawing. It is concluded that changes in permafrost and climate conditions of the Anadyr lowland do not exceed critical values of secular cycles of temperature fluctuations and the thickness of the seasonally thawed layer in coastal subarctic tundras. Hazardous are the Decadal fluctuations in the depth of seasonal thawing are recognized as hazardous and as causing exogenous cryogenic processes. The amplitude of these fluctuations reaches 15-25 % of the mean long-term values of the thickness of the seasonally thawed layer. Monitoring results confirm predictions of soviet geocryologists concerning secular climatic fluctuations and warming in the Eastern Subarctic from 1980-1990 to 2030-2040.