Simulation of climate changes in Northern Eurasia by two versions of the INM RAS Earth system model

Abstract

The study presents a simulation of climate change across Northern Eurasia during the 20th and 21st centuries using two different versions of the Earth system model developed by the Marchuk Institute of Numerical Mathematics at the Russian Academy of Sciences. Model version INMCM5 participates in CMIP6 and has the lowest equilibrium climate sensitivity (ECS) among the CMIP6 models. In the next model version, INMCM6, changes in the physical parameterisations lead to an increase in ECS by a factor of 2. Changes in near-surface temperature, precipitation, snow cover area and sea ice extent simulated by both model versions are compared with available observational and reanalysis data. Climate change predictions for the middle and end of the 21st century are provided by two model versions. Both model versions simulate similar climate changes for the upcoming two decades. After the middle of 21st century, the model version with high equilibrium climate sensitivity simulates stronger climate changes over Northern Eurasia than the model version with low sensitivity. But, in general, the ratio of predicted warming is much less than the ratio of ECS.