The INM RAS Climate Model: Current Status, Development Prospects, and Participation in the CMIP7 Climate Model Intercomparison Project

The report considers the INM RAS climate system model, which consists of two main blocks: the atmospheric general circulation model, including the land and soil surface block, and the ocean and sea ice circulation model. The model also includes reproduction of the carbon cycle components, an aerosol block, and parameterization of electrical phenomena. The model can also include atmospheric chemistry, ocean biochemistry, and other blocks. The presentation considers the model's reproduction of the modern climate and its changes since the 19th century. The model generally correctly reproduces the observed changes, including the globally averaged surface temperature and its geographical distribution, stratospheric temperature, and ocean heat absorption.

The report considers the problem of uncertainty in the equilibrium sensitivity to a doubling of CO2 concentration for a real climate system, as well as the model equilibrium sensitivity and transient response.

The results of the model simulation of climate and carbon cycle changes, including ocean, plant, soil and atmosphere carbon, are presented. A conclusion is made about the main sources of uncertainty in the carbon cycle simulation.

The climate model under consideration is also used in forecasts of weather and climate anomalies for a period of 1-3 months and 1-5 years, which start once a month and once a year, respectively. Some results of the model simulation of seasonal weather anomalies and climate anomalies are presented when calculating for 1-5 years from the real initial states of the climate system.

The CMIP7 climate model intercomparison project, participation in which is planned for 2025-2027, includes a set of mandatory numerical experiments, as well as a set of fast track experiments, the plan of which is consistent with the writing of the 7th IPCC AR, and various subprojects. Fast experiments include the simulation of the modern climate and its changes, and an extensive set of idealized experiments, the purpose of which is to study various mechanisms and feedbacks in the model climate system. An important block in this program of experiments is the calculation of the effective radiative forcing from various anthropogenic impacts on the climate system. The technique of calculating the effective radiative forcing is considered, as well as the calculated forcings for anthropogenic aerosols and greenhouse gases.