calc_TM_PET: Calculate Thornthwaite's potential evapotranspiration for...

In smwesten-usgs/swbr: swbr: a Soil-Water-Balance model implemented in R

Description

This function returns a value for potential evapotranspiration as calculated by Thornthwaite's potential evapotranspiration calculation method. This function is designed to be applied when air temperatures fall below 26.5 degrees C. The equation used here is given as equation 10 in Appendix 1 of Thornthwaite (1948). Note that the version implemented here returns *millimeters*, rather than *centimeters* of PET, and therefore the coefficient used here is '16' rather than '1.6'.

Usage

calc_TM_PET(air_temp_C, heat_index_I, TM_a)

Arguments

air_temp_C	Mean monthly air temperature at a station, in degrees Celcius.
heat_index_I	Annual heat index I for a station.
TM_a	Exponent a in Thornthwaite's PET calculation.

Value

Unadjusted potential evapotranspiration in millimeters.

References

Thornthwaite, C.W., 1948, An Approach toward a Rational Classification of Climate: Geographical Review, v. 38, no. 1, p. 55.

smwesten-usgs/swbr documentation built on Nov. 27, 2019, 2:07 p.m.