Atmospheric Centers of Action in the Northern Hemisphere: Current Features and Expected Changes in the 21st Century Based on Simulations with the CMIP5 and CMIP6 Ensembles of Climate Models

• Published in: Doklady earth sciences 2022-12, Vol.507 (2), p.1132-1139
• Main Authors: Mokhov, I. I., Osipov, A. M., Chernokulsky, A. V.
• Format: Article
• Language: English
• Subjects: 21st century; Analysis; Anthropogenic factors; Atmospheric models; Climate change; Climate models; Climatic Processes; Comparative analysis; Earth and Environmental Science; Earth Sciences; Global climate; Interannual variability; Modelling; Northern Hemisphere; Oceans; Regional climates; Siberian High; Simulation; Simulation methods; Summer; Variability; Winter
• ISSN: 1028-334X; 1531-8354
• DOI: 10.1134/S1028334X2260089X

Regional features of global climate changes are significantly related to the regimes of atmospheric centers of action (ACA) and their variability. The analysis of the expected ACA changes in the Northern Hemisphere was carried out using simulations with ensembles of modern climate models of the international projects CMIP5 and CMIP6 under the scenarios of anthropogenic forcings RCP8.5 and SSP5-8.5 in the 21st century. The most consistent estimates based on simulations with the ensembles of the CMIP5 and CMIP6 models were obtained for the weakening tendencies of the winter North American High and the summer Asian Low. For the winter Siberian High, a weakening trend was found to be more significant according to simulations with the CMIP6 ensemble of climate models. In a comparative analysis of ACAs detected by model simulations and ERA5 reanalysis data, in particular for the base period of 1981–2005, it was noted that, in general, the intensities of subtropical anticyclonic ACAs over the Atlantic and Pacific oceans are larger for summer than for winter according to both reanalysis data and model simulations. For the intensity of subpolar cyclonic ACAs over the Atlantic and Pacific oceans, the opposite peculiarity is noted: their intensity is generally higher for winter than for summer. At the same time, the interannual variability of the intensity of ACAs, characterized by a standard deviation, is generally greater in winter than in summer.