Figure 54. A schematic representation of the horizontal
and vertical grid structure for a relatively coarse resolution general
circulation model. The east-west cross-section in the top panel corresponds
to the boxed area of the grid on the bottom and indicates the terrain following ‘sigma levels’ on which the numerical calculations are carried out.
Because many important atmospheric phenomena (eg. individual cumulus clouds)
which influence the way the large-scale flow will develop are too small
to be resolved by the computational grid, their effects are ‘parameterised’
in terms of the characteristics of the large-scale flow.
|