If the sun was inside the sealed dome, the whole atmosphere would just be one ambient temperature. There would be a uniform heat all throughout the dome and no ice would exist, especially at the center of the FE where the "north pole" is. The sun's output is approximately 1000 Watts per meter-squared on the ground (Earth's ground). That's a lot of energy to contain inside a dome and somehow still have drastic temperature gradients. Earth would be a very hot greenhouse and we'd all be dead from the extreme heat caused by the intense solar output. Definitely not something the FE believers can explain away without resorting to mental gymnastics and ad hominem attacks. Additionally, if the Earth is stationary then the sun and moon are moving around inside the dome. Unless the circumference of the Earth at the equator is much, much smaller than it is claimed to be even by FE flatheads, then the sun would be moving in a circular pattern around the equatorial circumference at 1000 MPH. That would definitely have an effect one the atmosphere and air currents which would exacerbate the trapped heat problem as well. We won't even get into the whole problematic dynamics of how the day and night would work since light does not behave the way the FE operatives would like us to believe.