Model Constants and Miscellaneous Parameters¶
The VIC model requires the specification of many model parameters to run. While some parameters are spatially distributed (e.g. soil, vegetation, or snowbands), others are more appropriately held constant across the model domain.
Physical Constants¶
Physical constants are set in the vic_physical_constants.h
header file. These constants rarely need to be changed and the model must be recompiled after any modifications.
Model Constants and Parameters¶
Some model constants and model parameters need to be changed more frequently. VIC supports this through the use of the optional CONSTANTS
file. The path to this file should be specified in the global parameter file.
There are over 150 constants that can be changed through this file. An example CONSTANTS
file is shown below.
# Set HUGE_RESIST to smaller value
HUGE_RESIST 1e5
# Set EMISS_GRND to unrealistic value
EMISS_GRND 0.3
The table below lists the constants available for manipulation via the CONSTANTS
file. Descriptions will be added later or as needed. Default values can be found in initialize_parameters.c
Constant | Description |
---|---|
LAPSE_RATE | |
GAUGE_HEIGHT | |
HUGE_RESIST | |
ALBEDO_BARE_SOIL | |
ALBEDO_H20_SURF | |
EMISS_GRND | |
EMISS_ICE | |
EMISS_VEG | |
EMISS_SNOW | |
EMISS_H2O | |
SOIL_RESID_MOIST | |
SOIL_SLAB_MOIST_FRACT | |
VEG_LAI_SNOW_MULTIPLIER | |
VEG_MIN_INTERCEPTION_STORAGE | |
VEG_LAI_WATER_FACTOR | |
CANOPY_CLOSURE | |
CANOPY_RSMAX | |
CANOPY_VPDMINFACTOR | |
LAKE_TMELT | |
LAKE_MAX_SURFACE | |
LAKE_BETA | |
LAKE_FRACMIN | |
LAKE_FRACLIM | |
LAKE_DM | |
LAKE_SNOWCRIT | |
LAKE_ZWATER | |
LAKE_ZSNOW | |
LAKE_RHOSNOW | |
LAKE_CONDI | |
LAKE_CONDS | |
LAKE_LAMISW | |
LAKE_LAMILW | |
LAKE_LAMSSW | |
LAKE_LAMSLW | |
LAKE_LAMWSW | |
LAKE_LAMWLW | |
LAKE_A1 | |
LAKE_A2 | |
LAKE_QWTAU | |
LAKE_MAX_ITER | |
SVP_A | |
SVP_B | |
SVP_C | |
PHOTO_OMEGA | |
PHOTO_LAIMAX | |
PHOTO_LAILIMIT | |
PHOTO_LAIMIN | |
PHOTO_EPAR | |
PHOTO_FCMAX | |
PHOTO_FCMIN | |
PHOTO_ZENITHMIN | |
PHOTO_ZENITHMINPAR | |
PHOTO_ALBSOIPARMIN | |
PHOTO_MINMAXETRANS | |
PHOTO_MINSTOMCOND | |
PHOTO_FCI1C3 | |
PHOTO_FCI1C4 | |
PHOTO_OX | |
PHOTO_KC | |
PHOTO_KO | |
PHOTO_EC | |
PHOTO_EO | |
PHOTO_EV | |
PHOTO_ER | |
PHOTO_ALC3 | |
PHOTO_FRDC3 | |
PHOTO_EK | |
PHOTO_ALC4 | |
PHOTO_FRDC4 | |
PHOTO_THETA | |
PHOTO_FRLEAF | |
PHOTO_FRGROWTH | |
SRESP_E0_LT | |
SRESP_T0_LT | |
SRESP_WMINFM | |
SRESP_WMAXFM | |
SRESP_WOPTFM | |
SRESP_RHSAT | |
SRESP_RFACTOR | |
SRESP_TAULITTER | |
SRESP_TAUINTER | |
SRESP_TAUSLOW | |
SRESP_FAIR | |
SRESP_FINTER | |
SNOW_MAX_SURFACE_SWE | |
SNOW_LIQUID_WATER_CAPACITY | |
SNOW_NEW_SNOW_DENSITY | |
SNOW_NEW_SNOW_DENS_MAX | |
SNOW_DEPTH_THRES | |
SNOW_DENS_DMLIMIT | |
SNOW_DENS_DMLIMIT_FACTOR | |
SNOW_DENS_MAX_CHANGE | |
SNOW_DENS_ETA0 | |
SNOW_DENS_C1 | |
SNOW_DENS_C2 | |
SNOW_DENS_C3 | |
SNOW_DENS_C3_CONST | |
SNOW_DENS_C4 | |
SNOW_DENS_C4WET | |
SNOW_DENS_C5 | |
SNOW_DENS_C6 | |
SNOW_DENS_F | |
SNOW_DENS_EXP | |
SNOW_DENS_DENOM | |
SNOW_NEW_SNT_C1 | |
SNOW_NEW_SNT_C2 | |
SNOW_NEW_SNT_C3 | |
SNOW_NEW_BRAS_DENOM | |
SNOW_MIN_SWQ_EB_THRES | |
SNOW_A1 | |
SNOW_A2 | |
SNOW_L1 | |
SNOW_L2 | |
SNOW_NEW_SNOW_ALB | |
SNOW_ALB_ACCUM_A | |
SNOW_ALB_ACCUM_B | |
SNOW_ALB_THAW_A | |
SNOW_ALB_THAW_B | |
SNOW_TRACESNOW | |
SNOW_CONDUCT | |
SNOW_MAX_SNOW_TEMP | |
SNOW_MIN_RAIN_TEMP | |
BLOWING_KA | |
BLOWING_CSALT | |
BLOWING_UTHRESH | |
BLOWING_KIN_VIS | |
BLOWING_MAX_ITER | |
BLOWING_K | |
BLOWING_SETTLING | |
BLOWING_NUMINCS | |
TREELINE_TEMPERATURE | |
SNOW_DT | |
SURF_DT | |
SOIL_DT | |
CANOPY_DT | |
CANOPY_VP | |
TOL_GRND | |
TOL_OVER | |
FROZEN_MAXITER | |
MAX_ITER_GRND_CANOPY | |
NEWT_RAPH_MAXTRIAL | |
NEWT_RAPH_TOLX | |
NEWT_RAPH_TOLF | |
NEWT_RAPH_R_MAX | |
NEWT_RAPH_R_MIN | |
NEWT_RAPH_RELAX1 | |
NEWT_RAPH_RELAX2 | |
NEWT_RAPH_RELAX3 | |
NEWT_RAPH_EPS2 | |
ROOT_BRENT_MAXTRIES | |
ROOT_BRENT_MAXITER | |
ROOT_BRENT_TSTEP | |
ROOT_BRENT_T |