Utility functions for the calculation of biophysical variables.
biophysics_irradianceToPhotonFlux(I, lambda)
biophysics_leafTemperature(absRad, airTemperature, u, E, leafWidth = 1.0)
biophysics_leafTemperature2(SWRabs, LWRnet, airTemperature, u, E, leafWidth = 1.0)
biophysics_leafVapourPressure(leafTemp, leafPsi)
biophysics_radiationDiurnalPattern(t, daylength)
biophysics_temperatureDiurnalPattern(t, tmin, tmax,
tminPrev, tmaxPrev, tminNext, daylength)
biophysics_waterDynamicViscosity(temp)Irradiance (in W*m-2).
Wavelength (in nm).
Wind speed above the leaf boundary layer (in m/s).
Air temperature (in <U+00BA>C).
Minimum and maximum daily temperature (<U+00BA>C).
Maximum and minimum daily temperatures of the previous and following day (<U+00BA>C).
Absorbed long- and short-wave radiation (in W<U+00B7>m-2).
Absorbed short-wave radiation (in W<U+00B7>m-2).
Net long-wave radiation balance (in W<U+00B7>m-2).
Transpiration flow (in mmol H20<U+00B7>m-2<U+00B7>s-1) per one sided leaf area basis.
Leaf width (in cm).
Time of the day (in seconds).
Day length (in seconds).
Temperature (<U+00BA>C).
Leaf temperature (<U+00BA>C).
Leaf water potential (MPa).
Values returned for each function are:
biophysics_leafTemperature: leaf temperature (in <U+00BA>C)
biophysics_leafVapourPressure: leaf vapour pressure (in kPa)
biophysics_radiationDiurnalPattern: the proportion of daily radiation corresponding to the input time in seconds after sunrise.
biophysics_temperatureDiurnalPattern: diurnal pattern of temperature.
biophysics_waterDynamicViscosity: Water dynamic viscosity relative to 20<U+00BA>C.
Function biophysics_leafTemperature calculates leaf temperature according to energy balance equation given in Campbell and Norman (1988). Function biophysics_radiationDiurnalPattern follows the equations given in Liu and Jordan (1960). Function biophysics_temperatureDiurnalPattern determines diurnal temperature pattern assuming a sinusoidal pattern with T = Tmin at sunrise and T = (Tmin+Tmax)/2 at sunset and a linear change in temperature between sunset and Tmin of the day after (McMurtrie et al. 1990). Function biophysics_waterDynamicViscosity calculates water dynamic viscosity following the Vogel (1921) equation.
Campbell, G. S., and J. M. Norman. 1998. An introduction to environmental biophysics: 2nd edition. (eqns. 14.1 & 14.3)
B. Y. H. Liu and R. C. Jordan, <U+201C>The interrelationship and characteristic distribution of direct, diffuse and total solar radiation,<U+201D> Solar Energy, vol. 4, no. 3, pp. 1<U+2013>19, 1960.
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.
H. Vogel, "Das Temperaturabhangigkeitsgesetz der Viskositat von Flussigkeiten", Physikalische Zeitschrift, vol. 22, pp. 645<U+2013>646, 1921.