9. Implementation of the Multicloud Model in an Aquaplanet Global Climate Model

Global climate and numerical weather prediction models (GCMs and NWPMs) simulate the atmospheric large-scale dynamical processes by solving the hydrostatic or non-hydrostatic primitive equations on a fixed grid with a horizontal mesh size of 25 km to 200 km. Atmospheric processes occurring at smaller scales that cannot be represented on those coarse resolutions are either neglected or represented via subgrid models known as parameterizations [246, 132]. As already demonstrated in the previous chapters convective clouds have a major impact on the atmospheric dynamics on synoptic and planetary scales that cannot be ignored. Convectively coupled waves and convective motions in general make the bulk of the atmospheric circulation in the tropical latitudes and account for the majority of precipitation which falls in this part of the globe. Among those, the Madden-Julian oscillation (MJO) [164, 163], in particular, constitutes the major source of atmospheric variability on the intra-seasonal and planetary scales and interacts with important global weather an climate patterns [300, 302].