FORCE_TYPE defines which forcing variables are in the forcing file, and the order in which they appear. These lines must follow either FORCING1 or FORCING2, and N_TYPES so that the model knows which file to associate the columns with and how any columns are present. If the forcing file is in binary format, FORCE_TYPE must also define whether each value is a SIGNED or UNSIGNED short int and the factor by which it needs to be multiplied.

Possible forcing file data types are:

  • AIR_TEMP - sub-daily air temperature (C)
  • ALBEDO - surface albedo (fraction)
  • DENSITY - atmospheric density (kg/m^3)
  • PREC - precipitation (mm)
  • PRESSURE - atmospheric pressure (kPa)
  • SHORTWAVE - shortwave radiation (W/m2)
  • TMAX - daily maximum temperature (C)
  • TMIN - daily minimum temperature (C)
  • VP - atmospheric vapor pressure (kPa)
  • WIND - wind speed (m/s)
  • SKIP - used to indicate a data column which is not read into the model

Examples. a standard four column daily forcing data file will be defined as:

ASCII File

FORCING1  FORCING_DATA/LDAS_ONE_DEGREE/data_
N_TYPES    4
FORCE_TYPE  PREC
FORCE_TYPE  TMAX
FORCE_TYPE  TMIN
FORCE_TYPE  WIND
FORCE_FORMAT  ASCII
FORCE_DT  24

Binary File

FORCING1  FORCING_DATA/LDAS_ONE_DEGREE/data_
N_TYPES    4
FORCE_TYPE  PREC  UNSIGNED  40
FORCE_TYPE  TMAX  SIGNED    100
FORCE_TYPE  TMIN  SIGNED    100
FORCE_TYPE  WIND  SIGNED    100
FORCE_FORMAT  BINARY
FORCE_ENDIAN  LITTLE
FORCE_DT  24