ET-SCI cold-wave family index. Annual total number of days inside any
cold-wave event (see ck_cwn() for the cold-wave definition).
Arguments
- tmin
Numeric vector of daily minimum temperatures (degrees C).
- dates
Date vector of the same length as
tmax. Must contain data covering the reference period.- ref_start, ref_end
Integer. Reference period boundary years (inclusive). Defaults to 1961 and 1990.
- min_spell
Integer. Minimum spell length in days (default 3, the ET-SCI standard).
Examples
set.seed(1)
dates <- seq(as.Date("1961-01-01"), as.Date("1991-12-31"), by = "day")
tmin <- 5 + 8 * sin(2 * pi * as.integer(format(dates, "%j")) / 365) +
rnorm(length(dates))
tail(ck_cwf(tmin, dates))
#> period value index unit
#> 26 1986-01-01 0 cwf days
#> 27 1987-01-01 0 cwf days
#> 28 1988-01-01 3 cwf days
#> 29 1989-01-01 0 cwf days
#> 30 1990-01-01 0 cwf days
#> 31 1991-01-01 0 cwf days