Modeling of Climate, Atmospheric and Ocean Dynamics: To the 100th Anniversary of Academician G.I. Marchuk

Introductory paper on the issue of the journal Izvestiya, Atmospheric and Oceanic Physics, No. 3, 2025, dedicated to the 100th anniversary of Academician G.I. Marchuk. The main directions of scientific activity of G.I. Marchuk, which had a significant impact on the development of modern geophysical fluid dynamics, are described. These are weather forecasting; modeling of the climate system; application of the theory of adjoint equations to geophysical fluid dynamics problems; computational algorithms. The ideas and mathematical methods of modern geophysical fluid dynamics initiated by G.I. Marchuk and developed by his scientific school over the course of 25 years of the XX and 25 years of the XXI century are discussed. The bright deep mark that he left in science is noted, and the results obtained by him, his disciples and colleagues in the field of geophysical fluid dynamics are highlighted.