Input Variables

Below is a list of meteorological and vegetation input variables. These input variables may always be found in the vicNl_def.h file.

NOTE: except where noted, variables are interpreted according to the following convention:

  • For moisture fluxes in units of mm, the variable is the total input over the time step.
  • For moisture fluxes in units of mm/s, the variable is the average input rate over the time step.
  • For TMAX and TMIN, the variable is the maximum or minimum over the time step.
  • For most other variables the variable is the average over the time step.

NOTE: For sub-daily time steps, VIC assigns the beginning time to the record. For example, if the global parameter file variables FORCEYEAR, FORCEMONTH, FORCEDAY, and FORCEHOUR are 1948, 01, 01, and 00, respectively, and the variable FORCE_DT is set to 1 hour, then VIC assumes the first forcing record corresponds to the interval spanning 1948-01-01 00:00:00 and 1948-01-01 00:59:59. VIC's output for the first time step will also be labelled as 1948 01 01 00. The final time step of each day will be hour 23.

NOTE 2: Units are shown as "Default (ALMA)". To use ALMA units, the user must set ALMA_INPUT TRUE in the global parameter file. ALMA units correspond more closely to the units used by reanalysis products or GCMs.

| METEOROLOGY | | | | Variable | Description | Units | |------------ |--------------------------------------------------------- |----------------------- | | AIR_TEMP | Average air temperature | C (ALMA_INPUT: K) | | CHANNEL_IN | Incoming channel flow (total volume over the time step) | m3 | | CATM | Atmospheric CO2 mixing ratio | ppm | | CRAINF | Convective rainfall | mm (ALMA_INPUT: mm/s) | | CSNOWF | Convective snowfall | mm (ALMA_INPUT: mm/s) | | DENSITY | Atmospheric density | kg/m3 | | FDIR | Fraction of incoming shortwave that is direct | fraction | | LONGWAVE | Incoming longwave radiation | W/m2 | | LSRAINF | Large-scale rainfall | mm (ALMA_INPUT: mm/s) | | LSSNOWF | Large-scale snowfall | mm (ALMA_INPUT: mm/s) | | PREC | Total precipitation (rain and snow) | mm (ALMA_INPUT: mm/s) | | PRESSURE | Atmospheric pressure | kPa (ALMA_INPUT: Pa) | | QAIR | Specific humidity | kg/kg | | RAINF | Rainfall (convective and large-scale) | mm (ALMA_INPUT: mm/s) | | REL_HUMID | Relative humidity | fraction | | SHORTWAVE | Incoming shortwave | W/m2 | | SNOWF | Snowfall (convective and large-scale) | mm (ALMA_INPUT: mm/s) | | TMAX | Maximum daily temperature | C (ALMA_INPUT: K) | | TMIN | Minimum daily temperature | C (ALMA_INPUT: K) | | TSKC | Cloud cover | fraction | | VP | Vapor pressure | kPa (ALMA_INPUT: Pa) | | WIND | Wind speed | m/s | | WIND_E | Zonal component of wind speed | m/s | | WIND_N | Meridional component of wind speed | m/s | |------------ |--------------------------------------------------------- |----------------------- | | VEGETATION | | | | Variable | Description | Units | |------------ |--------------------------------------------------------- |----------------------- | | ALBEDO | Surface albedo | fraction | | LAI_IN | Leaf Area Index | fraction | | VEGCOVER | Partial Veg Cover Fract. (frac. of tile covered by veg) | fraction | | | ( = 1 - canopy gap fraction) | | |------------ |--------------------------------------------------------- |----------------------- | | MISCELLANEOUS | | | | Variable | Description | Units | |------------ |--------------------------------------------------------- |----------------------- | | SKIP | Place holder for unused data columns | Non-Data |