It is certainly true that the more air pressure, the more circulation. This is the major difference between Mars, Earth and Venus. I am not sure what the magic number is for atmospheric bars, and I would generally think it would also depend on the planet and it distance from the sun, but I think it is fair to say that a planet with 10 bars atmosphere is unlikely to have a 100 degree temp difference between the poles and the equator.
Yes as long as the atmosphere is transparent enough for light to reach the surface and get converted into IR and reradiated. The atmosphere is thicker at the equator of a rotating planet so the amount of energy entering at the equator that converts to heat and is radiated from the surface will be scattered more by the thicker atmosphere than at the polar regions. Also the angle of entry of sunlight at the polar regions relative the angle of the surface will cause much scattering and reduce the amount of energy the surface receives at the poles.
Hmm good question, Venus does not have a temperature difference, but then again it has 90bar atmosphere, at what pressure the atmosphere overpowers temperature difference I am not sure about.
That's very dependent on axial tilt, greenhouse gas levels, and clouds. Atmospheric gasses don't move much heat around, it's the hydro cycle that moves most heat through the atmosphere on earth. Atmospheric mixing won't overwhelm heat loss to space overnight if there's no water vapor. other greenhouse gasses, or clouds. It certainly won't overcome a 3 month night due to significant axial tilt.
It could. It would depend on various factors including the makeup of the atmosphere, the tilt of the orbit and whether there are currents the carry heat as the ocean currents do on earth.
Like could a planet with a 10 bar atmosphere have a 100 degree temperature difference between the poles and equator region if a day was 24 hours long?
