The boundary conditions at the Earth’s surface have a significant influence on the planetary and synoptic scale flows that form in the atmosphere. In the Earth’s real atmosphere, it is difficult to isolate and study the influence of boundary conditions because the spatial structure of large-scale flows and their temporal variations are strongly influenced by the distribution of land and ocean, surface relief, the hydrological cycle, and other factors. It is possible to study the role of the underlying surface using idealised models of Earth-like planets. This paper presents a comparative analysis of the structure and dynamics of the atmospheric general circulation and baroclinic waves for idealised, zonally homogeneous planets. Numerical experiments are performed using the WRF-ARW software package for the built-in characteristics of the Earth’s atmosphere and the terrestrial parameters of planetary motion and insolation. Three model configurations are considered, namely a desert planet, a desert planet with an equatorial ocean, and an aquaplanet with a fixed meridional temperature distribution. It is shown that the desert planet is characterised by strong seasonal variations, leading to remarkable features both in the structure of the mean general circulation and in the distribution of velocity and temperature pulsations. On a desert planet with an equatorial ocean, the meridional velocity and temperature pulsations are similar to those observed in the Earth’s atmosphere. They are concentrated at mid-latitudes and separated by height, with the maximum of temperature pulsations in the lower part of the troposphere and the maximum of velocity in its upper part. On the aquaplanet, the temperature pulsations are significantly smaller in amplitude and shifted into the middle layers of the troposphere. The simulations have shown that, despite zonally homogeneous boundary conditions and the absence of relief, the intensity, lifetime, phase and group velocity of the baroclinic waves vary significantly on all the model planets considered. On a desert planet and a mixed-type planet, there is a pronounced season of maximum wave activity. On the aquaplanet, there are no strong seasonal variations, but long intervals of westward blocking are observed. The spectral composition of the baroclinic waves and their seasonal variability have been analysed.
P. G. Frick (Wed,) studied this question.