For more details of changes in the IFS cycle 40r1, please see Cycle 40r1 release notes. Note the following additional changes to the SCM:
- semi-Lagrangian advection is now available and set as the default (previously only Eulerian advection was possible).
- the simplified physics is now available as an alternative to the full physics. The simplified physics is used in the tangent-linear code at ECMWF.
- new diagnostics quantities available (type of PBL, convection type, lowermost and uppermost levels of convection, ...)
Namelists
There are two namelist files in the scm-40r1.ref-oifs/test-run directory:
namelist.trref_winds_rel and namelist.trref_winds_rel.simpl
The former one defines non-linear physics, the latter one the simplified physics (you may be surprised how close the results from the two packages are). We expect most users to use the full non-linear physics option.
Radiation namelist
It is important to set NRADINT=0 in the namelist &NAERAD. If not the model will abort as the default configuration is for 3D runs where the IFS uses a reduced grid to compute the radiation.
Semi-Lagrangian
By default the semi-Lagrangian scheme is activated (LSLAG=.T.) with the physics being averaged along a trajectory (LSLPHY=.T.). This follows the defaults in the IFS.
If you like to use Eulerian advection set LSLAG=.F., reduce the model timestep (don't forget to change number of time steps accordingly) and disable the semi-Lagrangian physics by setting LSLPHY=.F.