The atmosphere model of the Geophysical Fluid Dynamics Laboratory (GFDL-AM2) is coupled to a slab ocean in order to analyse the monsoon's sensitivity to changes in various forcing parameters on a planet with idealized topography. This monsoon planet design of a water planet with a zonal circumglobal land stripe allows to extract the relevant monsoon behaviour and reduces the influence of topography. Besides the width and location of the land stripe, the atmospheric CO2 concentration, incoming solar radiation, sulfate aerosol concentration and surface albedo are variied. Horizontal grid resolution is 2° latitude x 2.5° longitude. For the vertical grid, a hybrid coordinate grid with 24 vertical levels is implemented. The lowest model level starts about 30 m above the surface and the top level is at about 3 hPa. The vertical resolution is decreasing towards higher altitudes. Advective and physics time steps are 10 minutes and 0.5 hours, for atmopsheric radiation 3 hours time steps are used. Instead of an ocean general circulation model, a mixed-layer slab ocean is used.