Materials of the International Conference
50th Anniversary of the International Geophysical Year
and Electronic Geophysical Year

16-19 September 2007 • Suzdal, Russia

Study of ocean response to climate changes in the 20th–22nd centuries simulated with a coupled atmosphere-ocean general circulation model

N. A. Diansky and E. M. Volodin

Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russia

Abstract

The results of numerical experiments with a coupled atmosphere-ocean general circulation model, developed in the Institute of Numerical Mathematics (INM), RAS, on the simulation of possible climate changes during the 21st–22nd centuries according to three IPCC scenarios of variations in the concentrations of greenhouse and other gases are considered. These experiments were carried out in a frame of International project on the reproduction of modern climate and on the simulation of climate changes with coupled models (so-called IPCC models). This project was initiated by WCCRP (see 4-th IPCC Report). The most of characteristics of climate changes in INM model are close to averaged ones in IPCC models. An increase in the near-surface air temperature during the 20th century and the features of the observed climate changes, such as warming in 1940–1950 and its slowing down in 1960–1970, are adequately reproduced in the model. According to the model, the air-temperature increase during the 22nd century (as compared to the end of the 20th century) varies from 2 K for the most moderate scenario to 5 K for the warmest scenario. According to INM model results, in the 22nd century, under all scenarios, at the end of summer, a complete or almost complete sea-ice melting will occur in the Arctic. According to the model, by the year 2200, the sea level will vary by 20 cm to 45 cm as compared to the level at the end of the 20th century. According to the analysis of ocean circulation changes in the coupled INM model the climate warming is accompanied by decreasing of a global ocean meridional heat trasport (MHT) from low to high latitudes. It is shown, that the spatial structure of the response in MHT is formed basically by dynamic factors – changes in meridional overturning circulation (MOC). The MOC changes in the upper layer of ocean form all features of the changes in MHT distributions. The MOC response in Atlantic and Indo-Pcific differ in their space patterns.

Citation: N. A. Diansky and E. M. Volodin (2007), Study of ocean response to climate changes in the 20th–22nd centuries simulated with a coupled atmosphere-ocean general circulation model, in: Materials of the International Conference '50th Anniversary of the International Geophysical Year and Electronic Geophysical Year', GC RAS, Moscow, doi:10.2205/2007-IGY50conf.

© 2007 Geophysical Center RAS and authors


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