= Set up a simulation with routage simple =
Author: J. Ghattas[[BR]]
Last revision: 2022/03/17, J. Ghattas [[BR]]


Routage simple is developped by Yann Meurdesoif using the same physics as the standard routage but having another parallelization.
It is currently available in branch ORCHIDEE_2_2.

== Do as follow if running without libIGCM ==
* Use revision 7526 or more recent on branch ORCHIDEE_2_2. Compile as default.
* Use file ${R_IN}/SRF/ROUTING/routing_simple.nc instead of standard routing.nc file. The file should keep the name routing_simple.nc in the run directory. R_IN=/projsu/igcmg/IGCM at ciclad and exists as well at jean-zay, irene and obelix.
* In orchidee.def (or run.def) set:
{{{
RIVER_ROUTING=y
ROUTING_METHOD = simple
}}}
* Use all xml files in ORCHIDEE/src_xml including context_routing_orchidee.xml
* Add in iodef.xml after inclusion of the context_orchidee.xml:
{{{
<context id="orchidee" src="./context_routing_orchidee.xml"/>
}}}
* There is a new restart file specific for the routage simple. It is created at first start of the model. It is called routing_restart.nc when written and to restart the simulation it should be called routing_start.nc.
* A new output file is written called diag_routing.nc. Some output are also avaialble in sechiba_history.nc.


== Do as follow when using libIGCM ==
* With LMDZOR
 * Install LMDZOR_v6.2_work. Update to have above revision 7526 or later for the source code and the latest revision of the config/LMDZOR_v6 folder. 
 * Create a new experiment using LMDZOR/clim_pdControl
 * In your experiment folder, copy COMP/orchidee.card_routage_simple into COMP/orchidee.card
 * If you want another experiment, see the difference to add in orchidee.card by comparing EXPERIMENTS/LMDZOR/clim_pdControl/COMP/orchidee.card and EXPERIMENTS/LMDZOR/clim_pdControl/COMP/orchidee.card_routage_simple
* With ORCHIDEE offline (under edition)
 * Install ORCHIDEE_2_2. You will get the HEAD of ORCHIDEE and ORCHIDEE_OL. Compile as usual.
 * Copy the experiement you want to use and make following modifications:
   * Set in PARAM/run.def:
{{{
RIVER_ROUTING=y
ROUTING_METHOD = simple
}}}
   * Modify in COMP/sechiba.card
   * Add xml file in COMP/orchidee_ol.card (or orchideedriver.card if using experiment with the new driver)