The growth temperature is estimated by approximating the diurnal temperature cycle with a sine curve, where daylight hours are determined by the day-of-year and latitude following (Jones, 2013).
calc_tgrowth(tmin, tmax, lat, doy)Arguments
Value
Growth temperature (degrees Celsius), a numeric value. Growth temperature is calculated as
$$ T_g = T_\text{max} \left( 1/2 + (1 – x^2)^{1/2}/(2 \cos^{–1} x) \right) + T_\text{min} \left( 1/2 – (1 – x^2)^{1/2}/(2 \cos^{–1} x) \right) $$ with $$ x = – \tan \lambda \; \tan \delta $$ where \(\lambda\) is latitude and \(\delta\) is the solar declination angle. The solar declination angle is calculated as described in Davis et al., 2017.
References
Davis, T. W. et al. Simple process-led algorithms for simulating habitats (SPLASH v.1.0): robust indices of radiation, evapotranspiration and plant-available moisture. Geosci. Model. Dev. 10, 689–708 (2017).
Jones, H. G. (2013). Plants and microclimate: a quantitative approach to environmental plant physiology. In Cambridge University Press.
Examples
if (FALSE) { # \dontrun{
tgrowth <- calc_tgrowth(
tmin = 10.0,
tmax = 30.0,
lat = 23.5,
doy = 180 )
} # }