wiki:Documentation/UserGuide/VerifyClimate

Version 3 (modified by mmcgrath, 7 years ago) (diff)

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Once you have run LMDZOR, the first question to ask yourself is: does the climate I'm getting make sense? There does not seem to be any straightforward way to answer this question, so this page is going to give ideas on how to procede.

Tip 1) Run a spinup of ORCHIDEE offline to get reasonable biomass and soil water pools, which seems to be fairly important if you are using the 11-layer hydrology. The only way to do this that I know of is to regrid the driver files to the resolution you are interested in (such files now exist for the CRU dataset for 128x118) and use those to run offline for 50 years or so. Then you can use the resulting restart files to start the LMDZOR calculation. This is not a trivial step! You also need to make sure that the land mask you are using matches what is found in LMDZOR. The way we came up with to do this was to run a one day simulation of LMDWOR without a restart and look at the resulting history files. There are variables inside the histday*nc files called CONTFRACOR and CONTFRACATM, which contain the fraction of each gridcell which have land. We made sure that all these pixels had climate variables in our regridded forcing files, even if it meant copying the forcing data from nearby pixels.

Tip 2) It takes at least 10 simulation years to get a good idea of the climate. It also takes some time to equilibrate the climate after starting from a restart, so it seems that you can plan on a simulation of at least 15 years: 5 years to equilibrate, and 10 years over which to calculate the average climate.

Once you have the simulation, you need to do the averaging, find data to compare to, and create graphs. The tool ATLAS appears to do this. I wasn't able to find much documentation on it, though.

(in French, only a few small mentions)

http://forge.ipsl.jussieu.fr/libigcm/wiki/DocUtilisateur

http://www.google.fr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=0CE4QFjAH&url=http%3A%2F%2Fwww-lsceinca.cea.fr%2FFORMATION_DOC%2FCours-modipsl-dec2010.pdf&ei=3j_GU93vN9HY0QXNh4CgCA&usg=AFQjCNFmxn8UfbgnT2jKt1ZGopvgH6d09g&bvm=bv.71126742,d.d2k&cad=rja

(in French, updated in 2007)

http://dods.ipsl.jussieu.fr/fast/

(in French, a summary of what ATLAS is)

http://wiki.ipsl.jussieu.fr/IGCMG/Outils/ferret/Atlas

It appears that the post-treatment proceeds in two steps: step 1 is to combine the raw data into files containing all the years you want to average over (given by SeasonalFrequency? in the config.card). Step 2 is to compare these files (located in JOBNAME/ATM/Analyse/SE/ in the IGCM directory tree...what comes before this depends on what you put in the config.card and what system you are running on) to a set of reference data. Step 2 then compares this data to the reference simulation or observations, depending on what you are trying to do.

As an example, let's say I have two simulations that I want to compare. /ccc/store/cont003/dsm/p529grat/IGCM_OUT/LMDZOR/PROD/amip/MCOUP/ATM/Analyse/SE/MCOUP_SE_1980_1981_1M_histmth.nc /ccc/store/cont003/dsm/p529grat/IGCM_OUT/LMDZOR/PROD/amip/TNV32/ATM/Analyse/SE/TNV32_SE_1980_1981_1M_histmth.nc

Notice that both of these runs have already been processed by the seasonal frequency script, and therefore the monthly simulation data has been combined into a single files covering two years (the length of SeasonalFrequency? in config.card).

If you have loaded all the ipsl paths on, for example, Curie, you should be able to find all the ferret scripts (*.jnl) and ATLAS configuration files (*.cfg) in the $FER_ATLAS directory.

ls $FER_ATLAS/

We are interested in comparing two simulations, which according to the webpage above, means we need a diag2 ATLAS script. If you open the LMDZ*diag2.cfg files with a text editor, you can look at all the variables they compare and decide if you want to run all of them, or just one. We create an empty directory somewhere to hold the output, and go to that directory.

mkdir ATLAS
cd ATLAS

Let's copy one of the ATLAS scripts here and modify it a bit.

cp $FER_ATLAS/atlas_p_LMDZ3.3_diag2_a.cfg test.cfg
ref=/ccc/store/cont003/dsm/p529grat/IGCM_OUT/LMDZOR/PROD/amip/TNV32/ATM/Analyse/SE/TNV32_SE_1980_1981_1M_histmth.nc
sed -e "s%your_reference_file=.*%your_reference_file=${ref}%" $FER_ATLAS/atlas_p_LMDZ3.3_diag2_a.cfg > atlas_p_LMDZ3.3_diag2_a.cfg

Now my 'reference' simulation is TNV32. If you decide that you want to run multiple .cfg scripts, you will have to run the "sed" line for each script you want to use.

atlas -o atlas_model_vs_model atlas_p_LMDZ3.3_diag2_*.cfg /ccc/store/cont003/dsm/p529grat/IGCM_OUT/LMDZOR/PROD/amip/MCOUP/ATM/Analyse/SE/MCOUP_SE_1980_1981_1M_histmth.nc

This command should be run in the same directory where I just created the modified .cfg files. With the "atlas_p_LMDZ3.3_diag2_*.cfg", it will run all the .cfg files that it finds matching that expression. The last argument is the name of the file I want to compare to my "reference" simulation, which I declared above.

The output of this command is a series of folders all grouped into "atlas_model_vs_model/". In there you have pdf and html summaries of all the variables, plus individual directories for each variable if you just want to look at one of them.