Physical parameterization

Parameterization is used to represent the important physical processes that cannot be explicitly presented in the grid-scale of a numerical model. Parameterization is necessary for several reasons:

(1) Computers are not yet powerful enough to treat many physical processes explicitly because the processes are either too small or too complex to be resolved.

(2) Many other physical processes cannot be explicitly modeled because they are not sufficiently understood to be represented in equation format or there are no appropriate data