$CTSMROOT/tools/README					Jun/08/2018

CTSM tools for analysis of CTSM history files -- or for creation or
modification of CTSM input files.
	
I.  General directory structure:

    $CTSMROOT/tools
	mksurfdata_esmf -- Create surface datasets.

        crop_calendars --- Regrid and process GGCMI sowing and harvest date files for use in CTSM.

        mkmapgrids ------- Create regular lat/lon SCRIP grid files

        site_and_regional  Scripts for handling input datasets for site and regional cases.
                           These scripts both help with creation of datasets using the 
                           standard process as well as subsetting existing datasets and overwriting
                           some aspects for a specific case.

        modify_input_files Scripts to modify CTSM input files. Specifically modifying the surface
                           datasets and mesh files.

        contrib ---------- Miscellaneous tools for pre or post processing of CTSM.
                           Typically these are contributed by anyone who has something
                           they think might be helpful to the community. They may not
                           be as well tested or supported as other tools.

    cime-tools ($CIMEROOT/tools/) (CIMEROOT is ../cime for a CTSM checkout and ../../../cime for a CESM checkout)
        $CIMEROOT/mapping/gen_domain_files
            gen_domain ------- Create data model domain datasets from SCRIP mapping datasets.

II. Notes on building/running for each of the above tools:

    mksurfdata_esmf has a cime configure and CMake based build using the following files:

        gen_mksurfdata_build ---- Build mksurfdata_esmf
        src/CMakeLists.txt ------ Tells CMake how to build the source code
        Makefile ---------------- GNU makefile to link the program together
        cmake ------------------- CMake macros for finding libraries

    mkmapgrids, and site_and_regional only contain scripts so don't have the above build files.

    Some tools have copies of files from other directories -- see the README.filecopies
    file for more information on this.

    Tools may also have files with the directory name followed by namelist to provide sample namelists.

	<directory>.namelist ------ Namelist to create a global file.

    These files are also used by the test scripts to test the tools (see the
    README.testing) file.

    NOTE: Be sure to change the path of the datasets references by these namelists to 
    point to where you have exported your CESM inputdata datasets.

III. Process sequence to create input datasets needed to run CTSM

    1.) Create SCRIP grid files (if needed)

       a.) For standard resolutions these files will already be created. (done)

       b.) To create regular lat-lon regional/single-point grids run site_and_regional/mknoocnmap.pl

        This will create both SCRIP grid files and a mapping file that will
        be valid if the region includes NO ocean whatsoever (so you can skip step 2).
        You can also use this script to create SCRIP grid files for a region
        (or even a global grid) that DOES include ocean if you use step 2 to
        create mapping files for it (simply discard the non-ocean map created by
        this script).

        Example, for single-point over Boulder Colorado.

           cd site_and_regional
           ./mknoocnmap.pl -p 40,255 -n 1x1_boulderCO

       c.) General case

        You'll need to convert or create SCRIP grid files on your own (using scripts
        or other tools) for the general case where you have an unstructured grid, or 
        a grid that is not regular in latitude and longitude.

       example format
         ==================	
          netcdf fv1.9x2.5_090205 {				   
          dimensions:						   
               grid_size = 13824 ;				   
               grid_corners = 4 ;				   
               grid_rank = 2 ;					   
          variables:						   
               double grid_center_lat(grid_size) ;		   
                       grid_center_lat:units = "degrees" ;	   
               double grid_center_lon(grid_size) ;		   
                       grid_center_lon:units = "degrees" ;	   
               double grid_corner_lat(grid_size, grid_corners) ;  
                       grid_corner_lat:units = "degrees" ;	   
               double grid_corner_lon(grid_size, grid_corners) ;  
                       grid_corner_lon:units = "degrees" ;	   
               int grid_dims(grid_rank) ;			   
               int grid_imask(grid_size) ;			   
                       grid_imask:units = "unitless" ;            

    2.) Create ocean to atmosphere mapping file (if needed)

        a.) Standard resolutions (done)

        If this is a standard resolution with a standard ocean resolution -- this
        step is already done, the files already exist.

        b.) Region without Ocean (done in step 1.b)

        IF YOU RAN mknoocnmap.pl FOR A REGION WITHOUT OCEAN THIS STEP IS ALREADY DONE.

        c.) New atmosphere or ocean resolution

        If the region DOES include ocean, use $CIMEROOT/tools/mapping/gen_domain_files/gen_maps.sh to create a 
        mapping file for it.

    Example:

    cd $CIMEROOT/tools/mapping/gen_domain_files
    ./gen_maps.sh -focn <ocngrid> -fatm <atmgrid> -nocn <ocnname> -natm <atmname>


    3.) Add SCRIP grid file(s) created in (1) into XML database in CTSM (optional)

        See the "Adding New Resolutions or New Files to the build-namelist Database" 
        Chapter in the CTSM User's Guide

  http://www.cesm.ucar.edu/models/cesm1.0/clm/models/lnd/clm/doc/UsersGuide/book1.html

         If you don't do this step, you'll need to specify the file to mksurfdata_esmf
         in step (3) using the "-f" option.

    4.) Convert map of ocean to atm for use by DATM and CTSM with gen_domain
        (See $CIMEROOT/tools/mapping/README for more help on doing this)

       - gen_domain uses the map from step (2) (or previously created CESM maps)

       Example:

        cd $CIMEROOT/tools/mapping/gen_domain_files/src
        gmake
        cd ..
        setenv CDATE       090206
        setenv OCNGRIDNAME gx1v6
        setenv ATMGRIDNAME fv1.9x2.5
        setenv MAPFILE $CSMDATA/cpl/cpl6/map_${OCNGRIDNAME}_to_${ATMGRIDNAME}_aave_da_${CDATE}.nc
        ./gen_domain -m $MAPFILE -o $OCNGRIDNAME -l $ATMGRIDNAME

        Normally for I compsets running CTSM only you will discard the ocean domain 
        file, and only use the atmosphere domain file for datm and as the fatmlndfrc 
        file for CTSM. Output domain files will be named according to the input OCN/LND
        gridnames.

    5.) Create surface datasets with mksurfdata_esmf on Derecho
        (See mksurfdata_esmf/README.md for more help on doing this)

       - gen_mksurfdata_build to build
       - gen_mksurfdata_namelist to build the namelist
       - gen_mksurfdata_jobscript_single to build a batch script to run on Derecho
       - Submit the batch script just created above

       - This step uses the results of step (3) entered into the XML database
         in step (4).
       - If datasets were NOT entered into the XML database, set the resolution
         by entering the mesh file using the options: --model-mesh --model-mesh-nx --model-mesh-ny

       Example: for 0.9x1.25 resolution fro 1850

       cd mksurfdata_esmf
       ./gen_mksurfdata_build
       ./gen_mksurfdata_namelist --res 0.9x1.25 --start-year 1850 --end-year 1850
       ./gen_mksurfdata_jobscript_single --number-of-nodes 24 --tasks-per-node 12 --namelist-file target.namelist
       qsub mksurfdata_jobscript_single.sh
   
       NOTE that surface dataset will be used by default for fatmgrid - and it will 
       contain the lat,lon,edges and area values for the atm grid - ASSUMING that 
       the atm and land grid are the same 

    6.) Add new files to XML data or using user_nl_clm (optional)

       See notes on doing this in step (3) above. 

IV.  Notes on which input datasets are needed for CTSM

       global or regional/single-point grids
         - need fsurdata and fatmlndfrc

      fsurdata ---- from mksurfdata_esmf in step (III.7)
      fatmlndfrc -- use the domain.lnd file from gen_domain in step (III.6)