Quantitative assessment and projections of permafrost temperature in the Magadan region using the GIPL2.0 model

Recently, Russia has seen an increase in permafrost temperatures, facilitating the development of hazardous geocryological processes. Estimates of climate change impacts on permafrost are often uncertain due to the lack of observational data, therefore mathematical modeling has become the primary method for studying geocryological conditions. The research objective was to evaluate the feasibility of the model GIPL2.0 for predicting permafrost characteristics in the mountain permafrost of the North-East. We utilized unique data from the regional permafrost monitoring network of the Magadan Region. The relevance of this study is confirmed by the need to consider risks and adapt permafrost regions to projected climate change. The verification of GIPL2.0 model was performed using ground temperature data from two boreholes for the period 2022–2025. A forecast of ground temperature and maximum thaw depth up to 2040 was produced based on data from the AMIP-LFMIP-rmLC experiment of the CMIP6 project. The model was verified to a depth of 10 m. The calculated ground temperature satisfactorily matches observations to a depth of 5 m. Deviations are due to uncertainties in determining the physical properties of the rocks and the impact of hydrological processes on profile heat dynamics, which are not described by the model algorithm. According to the climate change forecast, air temperatures in the upper reaches of the Kolyma River basin will increase by 0.9°C every five years. Projections of ground temperatures through 2040 at two boreholes showed that temperatures will increase at all depths, particularly in the sub-1-meter layer by 2–3°C. The maximum seasonal thaw depth at the Goltsy borehole will exceed 2 meters, while at the Pereval Kulu borehole, despite the increase in ground temperature, it will not increase. The study emphasizes the need to use in-situ data to verify geocryological models to improve forecast accuracy.