reference.ET: Reference Evapotranspiration

Description

Reference evapotranspiration calculated from the Penman-Monteith equation with a prescribed surface conductance. This function is deprecated. Use potential.ET(...,approach="Penman-Monteith") instead.

Usage

reference.ET(data, Gs_ref = 0.0143, Tair = "Tair",
  pressure = "pressure", VPD = "VPD", Rn = "Rn", Ga = "Ga_h",
  G = NULL, S = NULL, missing.G.as.NA = FALSE,
  missing.S.as.NA = FALSE, Esat.formula = c("Sonntag_1990",
  "Alduchov_1996", "Allen_1998"), constants = bigleaf.constants())

Arguments

data

Data.frame or matrix containing all required variables; optional

Gs_ref

Reference surface conductance (m s-1); defaults to 0.0143 m s-1.

Tair

Air temperature (degC)

pressure

Atmospheric pressure (kPa)

VPD

Vapor pressure deficit (kPa)

Net radiation (W m-2)

Aerodynamic conductance to heat/water vapor (m s-1)

Ground heat flux (W m-2); optional

Sum of all storage fluxes (W m-2); optional

missing.G.as.NA

if TRUE, missing G are treated as NAs, otherwise set to 0.

missing.S.as.NA

if TRUE, missing S are treated as NAs, otherwise set to 0.

Esat.formula

Optional: formula to be used for the calculation of esat and the slope of esat. One of "Sonntag_1990" (Default), "Alduchov_1996", or "Allen_1998". See Esat.slope.

constants

cp - specific heat of air for constant pressure (J K-1 kg-1) eps - ratio of the molecular weight of water vapor to dry air Rd - gas constant of dry air (J kg-1 K-1) (only if approach = "Penman-Monteith") Rgas - universal gas constant (J mol-1 K-1) (only if approach = "Penman-Monteith") Kelvin - conversion degree Celsius to Kelvin (only if approach = "Penman-Monteith")