utils: Physical utility functions

Description

Set of functions used in the calculation of physical variables.

Usage

utils_airDensity(temperature, Patm)
utils_atmosphericPressure(elevation)
utils_averageDailyVP(Tmin, Tmax, RHmin, RHmax)
utils_averageDaylightTemperature(Tmin, Tmax)
utils_latentHeatVaporisation(temperature)
utils_latentHeatVaporisationMol(temperature)
utils_psychrometricConstant(temperature, Patm)
utils_saturationVP(temperature)
utils_saturationVaporPressureCurveSlope(temperature)

Arguments

temperature

Air temperature (<U+00BA>C).

Tmin, Tmax

Minimum and maximum daily temperature (<U+00BA>C).

RHmin, RHmax

Minimum and maximum relative humidity (%).

Patm

Atmospheric air pressure (in kPa).

elevation

Elevation above sea level (in m).

Value

Values returned for each function are:

utils_airDensity: air density (in kg<U+00B7>m-3).
utils_atmosphericPressure: Air atmospheric pressure (in kPa).
utils_averageDailyVP: average (actual) vapour pressure (in kPa).
utils_averageDaylightTemperature: average daylight air temperature (in <U+00BA>C).
utils_latentHeatVaporisation: Latent heat of vaporisation (MJ<U+00B7>kg-1).
utils_latentHeatVaporisationMol: Latent heat of vaporisation (J<U+00B7>mol-1).
utils_psychrometricConstant: Psychrometric constant (kPa<U+00B7><U+00BA>C-1).
utils_saturationVP: saturation vapour pressure (in kPa).
utils_saturationVaporPressureCurveSlope: Slope of the saturation vapor pressure curve (kPa<U+00B7><U+00BA>C-1).

References

McMurtrie, R. E., D. A. Rook, and F. M. Kelliher. 1990. Modelling the yield of Pinus radiata on a site limited by water and nitrogen. Forest Ecology and Management 30:381<U+2013>413.

McMahon, T. A., M. C. Peel, L. Lowe, R. Srikanthan, and T. R. McVicar. 2013. Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: a pragmatic synthesis. Hydrology & Earth System Sciences 17:1331<U+2013>1363. See also: http://www.fao.org/docrep/x0490e/x0490e06.htm