The flow structure in a laboratory model of atmospheric general circulation

The first results of mathematical modeling in the formulation close to the new laboratory model of general atmospheric circulation are presented. A rotating layer of fluid with a small aspect ratio is considered. A localized ring heater is located at the periphery of the bottom, and a refrigerator, in the form of a disk, is placed in the central part of the upper boundary of the fluid layer. The ring heater simulates heating in the equatorial region, and the cooler - cooling in the polar region. The heater is shifted from the side wall to minimize its influence on the formation of flows. Zonal currents (east and west winds) characteristic of the equatorial region are realized in the upper part of the fluid layer. A good qualitative agreement between the experimental and numerical results is shown. The main goal of the calculations was to determine the average structure of the flow in axisymmetric and wave regimes. It is shown that, in the axisymmetric regime, a meridional circulation similar to the Hadley circulation with a relatively low level of velocity pulsations is realized. An increase in the rotational velocity leads to the formation of unstable baroclinic waves and a significant change in the meridional circulation structure. The intensity and structure of baroclinic wave motions are largely determined by the heating intensity. It is shown for the first time that in the laboratory model, at a relatively small value of the Rossby thermal number, it is possible to realize the meridional circulation with a structure similar to that observed in the atmosphere and consisting of the analogs of Hadley, Ferrell and polar cells. This confirms the perspective of the new laboratory model of atmospheric general circulation for identifying key factors that determine the structure and dynamics of large-scale atmospheric flows.