Both the above effects become less important, and even negligible, when a flow is imposed. When there is an initial wind that is not in geostrophic or thermal wind balance with the temperature and pressure gradient, Coriolis effects will lead to rotation. This can be avoided by subtracting off the initial wind in the model's Coriolis calculation, assuming it is geostrophic and there is no pressure gradient in the model input. With a frictional layer, this geostrophic wind may not necessarily equal the initial wind, or if it does the initial model wind will change with time due to friction. There are no open radiative or periodic lateral boundary options in the standard model.
Values have to be specified there.
Frictional turning or radiative cooling or PBL processes may lead to development of gradients at the boundary. Also waves may be partially reflected there. If using periodic conditions, you should set the map-scale factors to 1, Coriolis parameter to constant, and latitude and longitude to constant in the model input.