WhatIs: The ok strato parameter

The ok_strato parameter is a logical flag, i.e. to be set to "y" (or equivalently ".true.") or "n" (or equivalently ".false.") in the run.def file, in practice most often in the "vert.def" (or sometimes "gcm.def") file, as it is strongly linked to the model vertical resolution

Setting ok_strato=y is recommended in most cases as it implies:

• Some impact on the vertical discretization (i.e. where the model levels are placed)
• Some switches on physical parametrizations related to the impact of gravity waves (orographic and non-orographic)

Running with ok_strato=n would only be useful and advised if running with simple setups such as with 19 vertical layers (with old ~CMIP3-like physics packages) or for aquaplanets or without physics (in Held&Suarez configuration).

Note also that if ok_strato=n then the sponge layer is not used either (see the leapfrog routine).

09/05/2022