WhatIs: The makelmdz fcm script

The makelmdz_fcm script to compile LMDZ

The makelmdz_fcm script is the bash script that you use to compile LMDZ. This is where one sets various options (e.g which physics package to compile the model with, what grid resolution to use, etc.).

To list available options, run "makelmdz_fcm -h", which should return something like:

Usage :
makelmdz_fcm [options] -arch nom_arch exec
[-h]                       : brief help
[-d [[IMx]JMx]LM]          : IM, JM, LM are the dimensions in x, y, z (default: 96x72x19)
[-p PHYS]                  : set of physical parametrizations (in libf/phyPHYS), (default: lmd)
[-prod / -dev / -debug]    : compilation mode production (default) / developement / debug
[-c false/MPI1/OMCT]       : coupling with ocean model : MPI1/OMCT/false (default: false)
[-v false/orchidee2.0/orchidee1.9/true] : version of the vegetation model to include (default: false)
          false       : no vegetation model
          orchidee2.1 : compile using ORCHIDEE 2.1 (or more recent version)
          orchidee2.0 : compile using ORCHIDEE 2.0
          orchidee1.9 : compile using ORCHIDEE up to the version including OpenMP in ORCHIDEE : tag 1.9-1.9.5(version AR5)-1.9.6
          true        : (obsolete; for backward compatibility) use ORCHIDEE tag 1.9-1.9.6
[-chimie INCA/false]       : with INCA chemistry model or without (default: false)
[-cosp true/false]    : compile with/without cosp package (default: false)
[-cosp2 true/false]    : compile with/without cosp2 package (default: false)
[-cospv2 true/false]    : compile with/without cospv2 package (default: false)
[-inlandsis true/false]  : compile with/without inlandsis package (default: false)
[-rrtm true/false]    : compile with/without rrtm package (default: false)
[-rad old/rrtm/ecrad]    : compile with old/rrtm/ecrad radiatif code (default: old)
[-dust true/false]    : compile with/without the dust package by Boucher and co (default: false)
[-strataer true/false]    : compile with/without the strat aer package by Boucher and co (default: false)
[-isotopes true/false]    : compile with/without water isotopes in the physics
[-isoverif true/false]    : compile with/without verifications for water isotopes in the physics
[-diagiso true/false]    : compile with/without special diagnostics for water isotopes in the physics
[-isotrac true/false]    : compile with/without tracers of water isotopes in the physics
[-parallel none/mpi/omp/mpi_omp] : parallelism (default: none) : mpi, openmp or mixted mpi_openmp
[-g GRI]                   : grid configuration in dyn3d/GRI_xy.h  (default: reg, inclues a zoom)
[-io ioipsl/mix/xios]                   : Input/Output library (default: ioipsl)
[-include INCLUDES]        : extra include path to add
[-cpp CPP_KEY]             : additional preprocessing definitions
[-adjnt]                   : adjoint model, not operational ...
[-mem]                     : reduced memory dynamics (obsolete flag; always on in parallel mode)
[-filtre NOMFILTRE]        : use filtre from libf/NOMFILTRE (default: filtrez)
[-link LINKS]              : additional links with other libraries
[-j n]                     : active parallel compiling on ntask
[-full]                    : full recompiling 
[-libphy]                  : only compile physics package (no dynamics or main program)
[-fcm_path path]           : path to the fcm tool (default: tools/fcm/bin)
[-ext_src path]            : path to an additional set of routines to compile with the model
[-arch_path path]          : path to architecture files (default: arch)
 -arch nom_arch            : target architecture 
 exec                      : executable to build

The user must at the very least provide the name of the executable (typically "gcm") and the mandatory option "-arch" with the target architecture name (e.g. "local" or "gfortran_CICLAD").

Some extra info about various makelmdz_fcm options

-d IMxJMxLM

As LMDZ works on a fixed grid (set when compiling), option "-d" is also almost always used to specify the number of grid points iimxjjmxlllm (where iim is the number of points along longitude, jjm is the number of points along latitude and llm the number of atmospheric layers).

If compiling the 1D model, then only the number of layers (llm) needs be specified, e.g. -d 78 to compile lmdz1d.

-j n

With this option one can speed up compilation by letting make compile simultaneously (and if possible) up to n routines in parallel (note that this "parallel compilation" has nothing to do with the code being compiled for serial or parallel use as specified via option -parallel ...). In practice using -j 8 or -j 4 works well.

-parallel none/mpi/omp/mpi_omp

This option is to specify whether the model should be compiled in serial mode (default) or in parallel using MPI (mpi) only, or using OpenMP (omp) only, or both MPI and OpenMP (mpi_omp).

In practice, one most often needs to run in parallel and using both MPI and OpenMP, so -parallel mpi_omp is advised.

-io ioipsl/mix/xios

This option specifies which IO (Input/Output) library is going to be used by the model. Default is -io ioipsl, which is becoming depreciated for the GCM but mandatory for the 1D model. Note that when compiling with XIOS: -io xios on still needs to also use the IOIPSL library (which handles the reading of the run.def and companion files).

-full

Impose a full cleanup (i.e. removing past object and library files) to ensure recompiling the model from scratch.

21/03/2022