Function reference • ETo

All functions

adjust_wind_speed(): Adjust wind speed measurement to a 2-meter observation.

calc_act_vapor_pressure(): Calculate the actual vapor pressure given the saturation vapor pressure and relative humidity.

calc_clear_sky_radiation(): Calculate the clear sky radiation at a location given an elevation.

calc_etr_spatial(): Calculate a timeseries of ETo across a set of input rasters.

calc_extraterrestrial_rad(): Calculate the theoretical extraterrestrial radiation at a given latitude.

calc_inverse_relative_distance(): Calculate the inverse relative distance between the earth and sun for a given day.

calc_longwave_radiation(): Calculate the outgoing longwave radiation.

calc_net_radiation(): Calculate the net outgoing radiation.

calc_pressure(): Estimate the atmospheric pressure given elevation. This assumes a constant pressure of 101.3 kPa

calc_psychrometric_constant(): Calculate the psychrometric constant given air pressure.

calc_radiation_fraction(): Calculate fraction of radiation relative to clear sky radiation.

calc_sat_vapor_pressure(): Calculate the saturation vapor pressure given the daily average temperature.

calc_shortwave_radiation(): Calculate the outgoing shortwave radiation.

calc_solar_declination(): Given the Julian day, calculate the solar declination.

calc_sunset_hour_angle(): Given the latitude and solar declination, calculate the sunset hour angle.

calc_svp_slope(): Calculate the slope of the saturation vapor pressure curve.

etr_hargreaves(): Calculate reference ET using the Hargreaves method.

etr_penman_monteith(): Calculate daily total reference ET at a given point. Follows the steps outlined in Zotarelli et al (2010) https://unpkg.com/node-red-contrib-evapotranspiration@1.0.1/alogorithms/evapotranspiration%20ae45900.pdf.

get_days_from_raster(): Create a terra::rast() of julian days from a timeseries input.

get_elev_from_point(): Get the elevation in meters for a given latitude and longitude. Latitude/longitude must be in degrees with a geographic projection.

get_elev_from_raster(): Download a raster of elevation that matches the shape, resolution and projection of an input raster.

get_lat_from_raster(): Create a latitude raster from an input raster template.

lat_to_radians(): Convert latitude in degrees to radians.

rh: Downscaled daily CMIP6 relative humidity (%) projections across Montana for the 2015-01-01 to 2016-01-01 record.

srad: Downscaled daily CMIP6 downwelling shortwave solar radiaiton (W m^-2) projections across Montana for the 2015-01-01 to 2016-01-01 record.

tmax: Downscaled daily CMIP6 max temperature (K) projections across Montana for the 2015-01-01 to 2016-01-01 record.

tmean: Downscaled daily CMIP6 mean temperature (K) projections across Montana for the 2015-01-01 to 2016-01-01 record.

tmin: Downscaled daily CMIP6 min temperature (K) projections across Montana for the 2015-01-01 to 2016-01-01 record.

wm2_to_mj(): Convert radiation in watts per m^2 per day to MJ per m^2 per day.

ws: Downscaled daily CMIP6 wind speed (m s^-1) projections across Montana for the 2015-01-01 to 2016-01-01 record.