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titleExercise

Change to the experiment directory labelled by the date chosen:

Code Block
languagebash
titlee.g.
cd scratch/ENFO/2013102400/       #  your date may be different

There are two experiment directories: cf000 and pf001. cf000 is for the control forecast which is not used here. pf001 is the single perturbation forecast.

Code Block
languagebash
titleExercise : examine files in the experiment directory
cd pf001
ls

Understand what the different files in the experiment directory are for.

ICM* : these are the initial starting files. ICMGG* are the initial gridpoint files, ICMSH* are the initial spectral fields.

Use the 'grib_ls' command to examine the initial files:

Code Block
grib_ls ICMGGgc1dINIT
grib_ls ICMSHgc1dINIT

The file: namelistfc is the model 'NAMELIST'. It contains a list of variable settings or 'switches' that control what the model does. These variables are grouped into separate fortran namelists.

Creating the OpenIFS batch job

The namelist file: namelistfc

cp namelistfc fort.4

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Set the ensemble member

In IFS, each ensemble member uses the stochastic physics schemes to generate uncertainty. A random number 'seed' is used by the stochastic scheme to generate a different forecast. This random number seed is changed by altering the ensemble member value in the model's namelist. Each ensemble member must have a unique number and therefore random number seed, in order to produce a different forecast.

Info

Make a copy of the namelist file and edit it to set the ensemble member value to the one you are given.

Make sure you are in the 'pf001' directory.

Code Block
cp namelistfc mynamelist

vi mynamelist        # or use your favourite text editor; emacs etc.

and make the following changes to the namelist variables:

Code Block
CTYPE="pf",   ! change the type of forecast to perturbed

NENSFNB=2,    ! change the ensemble member number to your assigned value. This determines the random number seed for the stochastic physics.

LSTOPH_SPBS=true,  ! this enables the stochastic backscatter scheme in the model dynamics

LSPSDT=true,       ! this enables the stochastic scheme for the physics tendencies

 

Submit job: qsub jobN

Checking job status: qstatu

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