NAME
          clm - Input data files for LPJmL runs

     DESCRIPTION
          LPJmL is driven by monthly fields of temperature,
          precipitation, cloudiness and number of days with rain.
          Additionally static information on soil properties,
          geographic coordinates of climate and soil data, and mean
          annual atmospheric CO2 concentration are required. Except
          for CO2 all files are binary data including a header (except
          for the soil and lake fraction data).

        Structure of the header
          header name
               (7 byte char array, LPJCLIM for temp, precip, wet days
               and cloudiness, LPJGRID for coordinate data, LPJLUSE
               for land use data, LPJ_COW for country codes, LPJDAMS
               for reservoir data)

          header version
               (4 byte integer, currently set to 3, also used to
               determine if input data needs byte swapping)

          order
               (4 byte integer, values are either 1 (cellyear) or 2
               (yearcell))

          firstyear
               (4 byte integer, first year of data record)

          nyear
               (4 byte integer, total number of years)

          firstcell
               (4 byte integer)

          ncell
               (4 byte integer, number of grid cells represented)

          nbands
               (4 byte integer)

          cellsize_lon
               (4 byte float, longitude cellsize in deg)

          scalar
               (4 byte float conversion factor)

          cellsize_lat
               (4 byte float, latitude cellsize in deg)

          datatype
               (4 byte int, 0 for byte, 1 for short, 2 for int, 3 for
               float, 4 for double)


        Sorting of the climate data
          The sorting of the monthly climate data and of the land use
          data does not correspond to a standard file format but is a
          mixture of BSQ (band sequential) and BIP (band interleaved
          by pixel). You start with 12 monthly values (or with 24 land
          use-fractions) of the first year and first grid cell. After
          that, the first twelve monthly values of the second cell
          follow and so on. Once you are done with all grid cells, you
          continue with the first grid cell's monthly data of the
          second year. This format is called "cellyear" in the LPJmL
          vocabulary and is the only format that is supported from
          LPJmL-version 3.2 and above ("YEARCELL" = BIP has been used
          in previous LPJ-versions).  Once you have a data set that
          you want to apply, you use any programming language, to
          write the header to a file. In C, you can use the function
          fwriteheader(..)  in src/tools/header.c to write headers (or
          freadheader(...) to read it) Datasets can be converted to
          LPJ-format (including headers) from plain binary input files
          (BIP) with the executable cru2clm that has been provided
          with the LPJmL distribution.  Data needs to be stored in the
          same order as the input grid.

        Input data files
          soil data
               (1 file) data type char (1 byte), the grid needs to be
               the same as your input grid / climate data
               values are currently ranging from 0 to 9
               corresponding soil parameters can be found in
               par/soil.par
               no header


          climate data
               (all monthly values, 4 files + 1 file with atmospheric
               CO2 concentrations)

               - temperature [scaled: degree Celsius*10]
                 size of header: 38 bytes

               - precipitation [mm/month]
                 size of header: 38 bytes

               - cloudiness [%]
                 for internal computation of radiation
                 size of header: 38 bytes

               - wet days
                 number of wet days per month (needed only, if your

               are using the
                 "weather generator", that distributes rain within
               month randomly)
                 size of header: 38 bytes

               - atmospheric carbon dioxide [ppmv]
                 global annual mean CO2 concentration as ASCII file
                 format: year concentration
                 Example
                   1990 354.19
                   1991 355.59
                   1992 356.37
                   1993 357.04
                   1994 358.88

          Land use data

               - land use:
                 in C data type short (2 bytes), grid needs to be the
               same as your input grid / climate data
                 values range between 0 and 1000 (fraction *1000)
                 each grid cell and year has 24 entries: 12 for rain-
               fed crops, 12 for irrigated crops
                 crop order is as follows:
                 1: temperate cereals, 2: rice, 3: maize, 4: tropical
               cereals, 5: pulses,
                 6: temperate roots, 7: tropical roots, 8: oil crops
               sunflower, 9: oil crops soybean,
                 10: oil crops groundnut, 11: oil crops rapeseed, 12:
               pasture (C3/C4 mix left to LPJmL to determine)

               - country codes:
                 in C data type short (2 bytes)
                 for each cell two values: countrycodes (n=197) and
               regioncodes (n=433)

               - river routing:
                 in C data type int (4 bytes), the grid needs to be
               the same as your input grid / climate data
                 for each cell two values: one in which cell to rout
               the water
                                           one with the distance [km]
               between the midpoints of the two cells

                 -9: inland sink or outflow to the ocean


     AUTHORS
          For authors and contributors see AUTHORS file


     COPYRIGHT
          (C) Potsdam Institute for Climate Impact Research (PIK), see
          COPYRIGHT file


     SEE ALSO
          lpjml(1), cru2clm(1), txt2clm(1), catclm(1), grid2clm(1),
          cft2clm(1), printclm(1), printheader(1)