mc_calc_vpd {myClim}

Calculate vapor pressure deficit (in kPa)

Description

This function creates a new virtual sensor on locality within the myClim data object. The virtual sensor represents the vapor pressure deficit (in kPa) calculated from temperature and relative air humidity.

Usage

mc_calc_vpd(
  data,
  temp_sensor = "HOBO_T",
  rh_sensor = "HOBO_RH",
  output_sensor = "VPD",
  elevation = 0,
  metadata_elevation = TRUE,
  localities = NULL
)

Arguments

data

cleaned myClim object see myClim-package

temp_sensor

name of temperature sensor. Temperature sensor must be in T_C physical.

rh_sensor

name of relative air humidity sensor. Humidity sensor must be in RH physical.

output_sensor

name of new virtual VPD sensor (default "VPD")

elevation

value in meters (default 0)

metadata_elevation

if TRUE then elevation from metadata of locality is used (default TRUE)

localities

list of locality_ids for calculation; if NULL then all (default NULL)

Details

Equation are from the CR-5 Users Manual 2009–12 from Buck Research. These equations have been modified from Buck (1981) and adapted by Jones, 2013 (eq. 5.15) Elevation to pressure conversion function uses eq. 3.7 from Campbell G.S. & Norman J.M. (1998).

Value

myClim object same as input but with added VPD sensor

References

Jones H.G. (2014) Plants and Microclimate, Third Edit. Cambridge University Press, Cambridge Buck A.L. (1981) New equations for computing vapor pressure and enhancment factor. Journal of Applied Meteorology 20: 1527–1532. Campbell G.S. & Norman J.M. (1998). An Introduction to Environmental Biophysics, Springer New York, New York, NY

Examples

agg_data <- mc_calc_vpd(mc_data_example_agg, "HOBO_T", "HOBO_RH", localities="A2E32")