Calculation Library#

Every hydrometeorological calculation in the library, grouped by the module it lives in.

Each calculation is a single function. Click on a name for its equation, the paper or standard it comes from, its units, and the meaning of every argument. The rules for what you can pass in and what comes back are the same for all of them, and are set out in Flexible inputs.

meteorology#

Radiation balance and atmospheric-state variables. Full page: meteorology.

`absolute_humidity`	Calculate absolute humidity Q [g m-3]
`albedo`	Calculate albedo [unitless fraction]
`is_snow_day`	Calculate if a given day is a snow day.
`mean_sea_level_pressure`	Calculate mean sea level pressure (mslp) [hPa]
`mean_soil_heat_flux`	Calculate the mean soil heat flux (g) from two soil heat flux measurements [W m-2]
`net_radiation`	Calculate net radiation (rn) [W m-2]
`solar_zenith`	Calculate the solar zenith angle (theta_s) [radians]

evapotranspiration#

The FAO-56 Penman-Monteith calculation and the intermediate variables it is built from, and evapotranspiration from the latent heat flux of the surface energy balance. Full page: evapotranspiration.

`actual_vapour_pressure`	Actual vapour pressure (ea) [kPa]
`evapotranspiration_from_latent_heat_flux`	Evapotranspiration (ET) from latent heat flux [mm h-1]
`latent_heat_flux`	Latent heat flux (LE) as the residual of the surface energy balance [W m-2]
`latent_heat_of_vaporization`	Latent heat of vaporization (lambda) [MJ kg-1]
`potential_evapotranspiration_30min`	Calculate potential evapotranspiration (pet) [mm 30min-1]
`psychrometric_constant`	Psychrometric constant (gamma) [kPa degC-1]
`saturation_vapour_pressure`	Saturation vapour pressure (es) [kPa]
`vapour_pressure_curve_slope`	Slope of vapour pressure curve (delta) [kPa degC-1]
`wind_speed_height_correction`	Convert wind speed to 2m height [m s-1]

cosmos (soil moisture)#

Cosmic-ray neutron sensor corrections, soil moisture, and snow water equivalent. Full page: cosmos (soil moisture).

`absolute_humidity_factor`	Calculate absolute humidity correction factor to neutron counts [unitless]
`atmospheric_pressure_factor`	Calculate atmospheric pressure correction factor to neutron counts [unitless]
`correct_counts`	Calculate corrected neutron counts using correction factors [counts h-1]
`d86`	Calculate D86 value [cm]
`effective_depth`	Original effective depth calculation from SIMPLE VWC method [cm]
`neutron_intensity_factor`	Calculate incoming neutron count intensity correction factor using a background reference station [unitless]
`sigma_snow_water_equivalence`	Calculate uncertainty in a snow water equivalence (SWE) calculation for the above ground COSMOS sensor [mm water equivalent]
`sigma_snow_water_equivalence_snowfox`	Calculate uncertainty in a snow water equivalence (SWE) calculation for a below ground (SnowFox) COSMOS sensor [mm water equivalent]
`snow_estimated_counts`	Calculate CRNS count estimates when there is snow [counts h-1]
`snow_water_equivalence`	Calculate snow water equivalence (SWE) for an above ground COSMOS sensor [mm water equivalent]
`snow_water_equivalence_snowfox`	Calculate snow water equivalence (SWE) for a below ground (SnowFox) COSMOS sensor [mm water equivalent]
`soil_moisture_index`	Calculate soil moisture index (SMI) [unitless, 0-2]
`volumetric_water_content`	Calculate volumetric water content (VWC) from corrected neutron counts and site annotations [%]