Introduction to the ORCHIDEE configurations using libIGCM

Documentation for how to use ORCHIDEE with libIGCM and modipsl

ORCHIDEE is distributed using modipsl and scripts for libIGCM are available for running. Theses tools are developped by the platform group at ICMC "le pole de modelisation de l'IPSL". To learn how to use these tools:

• Follow the 2 basics courses given twice a year ​http://forge.ipsl.jussieu.fr/igcmg_doc/wiki/Train
• Read the documentation ​http://forge.ipsl.jussieu.fr/igcmg_doc/wiki/Doc

In complement to the igcmg_doc documentation, you find in this wiki specific information and help to use ORCHIDEE.

libIGCM is an an Sytem Running Environment. It is used to manipulate input and output files for an executable (or a set of executables in a coupled configuration). libIGCM is a library of scripts to launch simulations and post-treatment. Modularity and portability make your jobs work on a several machines(super-computer center) used at IPSL in the same way. libIGCM include a master job and auxiliary jobs for post-treatements. libIGCM is documented in the platform/documentation mentioned above.

ORCHIDEE offline configuration

The trunk version of the scripts are under development. Follow here the latest modifications on ORCHIDEE_OL.
After installation of modipsl and the offline ORCHIDEE model, the configuration directory modipsl/config/ORCHIDEE_OL will also be installed. In this directory the following experiment directories are found: There are four basic directories (configuration) to run ORCHIDEE in a simple mode :

1. OOL_SEC_STO_FG2 : run orchidee_ol with the full ORCHIDEE model.
2. OOL_SEC: used to run orchidee_ol without STOMATE and LPJ (SECHIBA with prescibed LAI).
3. SPINUP_ANALYTIC_FG1: used to run the full orchidee_ol with SPINUP_ANALYTIC activated in the model
4. TESTSTOMATE : OBSOLETE run teststomate executable for only STOMATE and LPJ part of the model
5. FORCESOIL : OBSOLETE run forcesoil executable to converge the soil carbon pools
6. SPINUP : OBSOLETE, this directory do not follow the standard way for use of libIGCM, see more below
7. ENSEMBLE : Specific set up to run ensemble, used to run FLUXNET site simulations, this set up do not follow the standard way for use of libIGCM.

Each of those directories contains (except SPINUP and ENSEMBLE) :

• a config.card file to describe the configuration (JobName, LongName, TagName, CalendarType, ListOfComponents, !Restarts and !Post)
• in COMP directory, you may find "card" and "driver" files for each components list in ListOfComponents section of config.card. The card files describes all files that are copied to or from the temporary run directory.
• in PARAM directory you find the parameter files needed to run the model such as run.def file and iodef.xml
• in POST directory contains specific files to configure the MONITORING

Some important remarks :

1. The type of the calendar (CalendarType) and the dates (DateBegin and DateEnd) are only use by the scripts to get the right input (forcings, maps ...) files, but they are not passed to the model. For ORCHIDEE model, the forcing file decides on the calendar that will be used.
2. Two keywords, _AUTO_ and _AUTOBLOCKER_, are used in the parameter files(run.def and file_def_orchidee.xml) to design parameters that will be set by the driver scripts find in COMP directory. A parameter which is set equal _AUTO_ can be modified by the user directly in the run.def file if wanted. In that case, the drivers can not overwrite it. The _AUTOBLOCKER_ variables can not be modified. If still this is done directly in run.def, the script will be stopped.

SPINUP and SPINUP_ANALYTIC

Last revision: 2020/02/28, F. Maignan

Spinup of the model is needed to find a stable initial state for historical simulations.

The equilibrium of the physics of the land surface (SECHIBA part of ORCHIDEE) should be reached in less than 10 years with a constant climatology and a prescribed LAI. You may take care of the years of the forcing files because El Niño or La Niña specific years may give bad results for a global spinup.

The equilibrium of the LAI (seasonal variation of the vegetation) takes less than two decades to converge. There is a big feedback between the LAI and the hydrology and energy budgets.

The soil passive carbon pool takes thousands of years to converge, but there is no feedback between the soil carbon pools and the LAI and the hydrology yet.

• Recommended method: An iterative pseudo-analytical method has been implemented in ORCHIDEE to find the equilibrium for the carbon pools more quickly. The experiment directory SPINUP_ANALYTIC makes use of this method. Using this method, still the living biomass and the hydrology need time to spin up.
• The previous method to accelerate the spinup used the programmes forcesoil and teststomate. forcesoil was used to accelerate the convergence of the soil carbon pools only and teststomate was accelerating the spinup of the living biomasse. The directory SPINUP is used to spinup with this method. IMPORTANT: SPINUP directory is not maintained. Read more about the method in directory SPINUP.

ENSEMBLE

With this experiment directory, you can change the forcing files and all parameters (by vegetation - PFTs - or not) to build all ENSEMBLE experiments you want with ORCHIDEE model.

For each experiment, this configuration will use the SPINUP configuration as a skeleton to launch a set of jobs.

This ENSEMBLE configuration can be used for setting an ensemble of simulations over different FLUXNET sites. In this case, the vegetation repartition has to be prescribed. It provides a tool to validate ORCHIDEE model on a grid of sites (one point for each simulation) all over the world. It give fast spinup and simulation on a various set of vegetation and climate distributions.

See page FluxnetValidation for a complete documentation on FLUXNET sites validations.

ORCHIDEE coupled configurations

ORCHIDEE can be used for coupled simulations with LMDZ such as LMDZOR or IPSLCM. Read more in the ​igcmg_doc about these configurations.