SNOWPACK 20240621.6fbafe7
Advanced simulation setup

Spatial resampling

Through MeteoIO, it is possible to force Snowpack with data that has not been measured locally. The forcings are then extracted for example from gridded data (such as the outputs of weather forecasting models or reanalysis models) or by spatially interpolating stations' data to the point of interest. For the data extraction or interpolation, please refer to MeteoIO's documentation section "Spatial resampling" (see for example the current stable release documentation).

Spatial resampling

The SLOPE_FROM_SNO configuration key in the [Input] section controls whether slope angle and azimuth are taken from the sno file or from the meteorological forcings (in this case, automatically extracted from either the gridded data or from the DEM used for the spatial interpolations). Please note that this won't change the meteorological forcings (they are always only valid for their associated coordinates on flat field) but will allow Snowpack to reproject the precipitation and radiation fields on the slope (angle and azimuth) of your choice.

When relying on spatially interpolated values, it is often necessary to first run Snowpack at the real forcing locations in order to generate easier to interpolate fields (such as ISWR, ILWR, PSUM) and then run the virtual stations by spatially interpolating the computed variables. In this case, it is recommended to run the first set of simulations with the following set of keys:

[Output]
TS_WRITE = TRUE
TS_FORMAT = SMET
TS_DAYS_BETWEEN = 0.04166667 ;so we get hourly values
OUT_CANOPY = FALSE
OUT_HAZ = FALSE
OUT_SOILEB = FALSE
OUT_HEAT = FALSE
OUT_T = FALSE
OUT_STAB = FALSE
OUT_LW = TRUE
OUT_SW = TRUE
OUT_MASS = TRUE
OUT_METEO = TRUE
AVGSUM_TIME_SERIES = TRUE
CUMSUM_MASS = FALSE
PRECIP_RATES = FALSE

And the second set of simulations (ie the ones relying on spatially interpolated forcings) with this set of keys:

[Input]
METEO = SMET
[InputEditing]
*::EDIT1 = MOVE
*::ARG1::DEST = PSUM_S
*::ARG1::SRC = MS_Snow
*::EDIT2 = MOVE
*::ARG2::DEST = PSUM_L
*::ARG2::SRC = MS_Rain
*::EDIT3 = MOVE
*::ARG3::DEST = HS
*::ARG3::SRC = HS_meas
*::EDIT4 = MOVE
*::ARG4::DEST = TSG
*::ARG4::SRC = T_bottom
*::EDIT5 = MOVE
*::ARG5::DEST = TSS
*::ARG5::SRC = TSS_meas
*::EDIT6 = KEEP
*::ARG6::PARAMS = TA TSS TSG RH ISWR ILWR HS VW DW PSUM_S PSUM_L PSUM PSUM_PH
*::EDIT7 = CREATE
*::ARG7::PARAM = PSUM_PH
*::ARG7::ALGORITHM = PRECSPLITTING
*::ARG7::TYPE = THRESH
*::ARG7::SNOW = 274.35
*::EDIT8 = CREATE
*::ARG8::PARAM = PSUM
*::ARG8::ALGORITHM = PRECSPLITTING
*::ARG8::TYPE = THRESH
*::ARG8::SNOW = 274.35
[SNOWPACK]
ENFORCE_MEASURED_SNOW_HEIGHTS = FALSE