Compute the Century DEFAC annual climate rate modifier.

Annual Century DEFAC rate-modifying factor: the original monthly-Century Poisson temperature factor (normalized to 1 at the 35 degree optimum) and the precipitation-over-evapotranspiration logistic moisture factor, multiplied and averaged over the supplied series.

Usage

soc_rate_modifier_century(temp_c, precip_mm, pet_mm)

Source

Parton, W. J., Schimel, D. S., Cole, C. V. & Ojima, D. S. (1987). doi:10.2136/sssaj1987.03615995005100050015x ; SoilR implementation: Sierra, C. A., Mueller, M. & Trumbore, S. E. (2012). doi:10.5194/gmd-5-1045-2012 .

Arguments

temp_c

Numeric monthly air (or soil-surface) temperature series (degrees Celsius).

precip_mm

Numeric monthly precipitation series (mm).

pet_mm

Numeric monthly potential evapotranspiration series (mm).

Value

The annual mean of the temperature-by-moisture product (a single numeric).

Examples

soc_rate_modifier_century(
  temp_c = c(15, 25, 35),
  precip_mm = c(40, 60, 80),
  pet_mm = c(50, 70, 90)
)
#> [1] 0.6914709