phenModel (version 1.0)

get_total_info: Compute Day Length, Mean Temperature, Thermal Units, and Cumulative Chill Days

Description

Computes daily day length, mean temperature, thermal units and cumulative number of chill days for a dataset.

Usage

get_total_info(Tmax, Tmin, Tbase, lat, day)

Arguments

Tmax

a vector of daily maximum temperatures

Tmin

a vector of daily minimum temperatures

Tbase

the base temperature used to define a chill day

lat

the latitude

day

day of the year (vector)

Value

Returns a data.frame with the day lengths, mean temperatures, thermal units and cumulative number of chill days.

Details

Implements the method by Forsythe et al. (1995) to calculate the day length, and the single-sine degree-day method to compute the thermal units.

References

Cannell, M.G.R., Smith, R.I. (1983) Thermal time, chill days and prediction of budburst in Picea sitchensis. Journal of Applied Ecology, 20(3), 951<U+2013>963.

Forsythe et al. (1995) A model comparison for daylength as a function of latitude and day of the year. Ecological Modeling 80:87-95.

Examples

# NOT RUN {
data(casement9596)

with(casement9596, get_total_info(Tmax, Tmin, Tbase = 7, Lat, day))
# }