Cheoa3 is integrated on the same atmospheric model grid than atmoa3. Its timestep is 7200 seconds; it therefore performs 72 timesteps per 6-day run.
As the other toymodels, cheoa3 performs, at the beginning of a run, appropriate PSMILe calls to initialize the coupling, define its grids, and declare its I/O or coupling variables; it also retrieves a local communicator if needed. As cheoa3 has the same grid than atmoa3, a direct exchange of coupling fields can occur between those two models, without going through OASIS3 interpolation process. To insure this, the coupling field must have a field status `IGNORED' or `IGNOUT' in the OASIS3 configuration file namcouple (see section 5.3) and the two models must have also the same parallel decomposition. Cheoa3 decomposition is hardcoded the same way than atmoa3, and if the user modifies the atmoa3 decomposition, he has to modify the cheoa3 decomposition the same way by changing cheoa3 values for il_nbcplproc and cdec (see below).
At the beginning of its timestep, cheoa3 calls the PSMILe prism_get routine to request Field10 (see table 8.1). At the end of its timestep, cheoa3 calls PSMILe prism_put routine to send Field11.
Finally, at the end of the run, cheoa3 performs the PSMILe finalisation call.