Experiment 1 - Adding rotation#

In this experiment, we will enable the effects of rotation.

Note that even though the rotation rate is non-zero:

Listing 7 app/lfric_atm/rose-app.conf#
[namelist:planet]
cp=14300.00
gravity=9.81
omega=7.292116E-5
p_zero=100000.0
rd=4124.00
scaling_factor=1.0

rotation is actually switched off in the equations formulation section:

Listing 8 app/lfric_atm/rose-app.conf#
[namelist:formulation]
dlayer_on=.true.
dry_static_adjust=.true.
eos_method='sampled'
exner_from_eos=.false.
horizontal_physics_predictor=.false.
horizontal_transport_predictor=.false.
init_exner_bt=.true.
l_multigrid=.true.
lagged_orog=.true.
moisture_formulation='traditional'
moisture_in_solver=.true.
p2theta_vert=.true.
rotating=.false.
shallow=.true.
si_momentum_equation=.false.
theta_moist_source=.true.
use_multires_coupling=.false.
use_physics=.true.
use_wavedynamics=.true.
vector_invariant=.false.
Planetary parameters section in Rose GUI

Fig. 36 Rose GUI: planetary parameters (planet namelist).#

Dynamics parameters section in Rose GUI

Fig. 37 Rose GUI: dynamics parameters enabling rotation (formulation namelist).#

So we first enable rotation and then we can also play with the rotation rate.

Step 1: Switch on rotation#

  1. Open Rose GUI or app/lfric_atm/rose-app.conf in a text editor of your choice.

Running graphical applications over SSH

If you are connected to a remote system over SSH, graphical applications need X11 forwarding to display on your computer. Start an X server on your computer first (for example, XQuartz on macOS), then connect from a terminal using generic host details supplied by your service:

$ ssh -AY <remote-host>

Repeat the options for every additional SSH hop. The -Y option enables trusted X11 forwarding. The -A option forwards your SSH authentication agent and should only be used with systems you trust. A terminal integrated into an editor such as VS Code works in the same way as any other terminal.

On the system where you will start the graphical application, run echo "$DISPLAY". It should return a value. If it is blank, disconnect and reconnect with X11 forwarding enabled at every hop before continuing.

rose edit &

See also

For help choosing the correct Monsoon3 service and finding the official setup guidance, see Using Monsoon3.

rose edit &

Note

You must be using the Cylc host to access rose-edit.

What does the rose-edit & command do?

  • This command opens the suite in the Rose graphical user interface, allowing you to view and modify its configuration.

  • The & at the end runs the GUI in the background, so your terminal remains available for other commands.

  1. Search for the rotating key.

  2. Change it to .true..

Step 2: Run the model#

Now run the model using what you have learnt in the previous exercises. Check the output using Python or another tool of your choice.

Step 3. Compare with the control experiment#

Using a Python script or Jupyter Notebook, make plots for both experiments and compare them to each other to see the effect of rotation.