growing.season.length: Flexible GSL function

Description

This function computes the growing season length (GSL) given the input, which is allowed to vary considerably from the ETCCDI definitions.

Usage

growing.season.length(daily.mean.temp, date.factor, dates, northern.hemisphere,
  min.length = 6, t.thresh = 5, gsl.mode = c("GSL", "GSL_first",
  "GSL_max", "GSL_sum"))

Arguments

daily.mean.temp

Timeseries of daily mean temperature (in degrees C), padded out to end on a year boundary (ie: starts on January 1st of some year, ends on December 31st).

date.factor

Factor of the same length as daily.mean.temp that divides the timeseries up into years of data.

dates

The corresponding series of dates.

northern.hemisphere

Whether the data is from the northern hemisphere.

min.length

The minimum number of days above or below the threshold temperature that defines the start or end of a growing season.

t.thresh

The temperature threshold for being considered part of a growing season (in degrees C).

gsl.mode

The growing season length mode (ETCCDI mode is "GSL").

Value

A vector containing the number of days in the growing season for each year.

Details

This function is the function used to implement climdex.gsl. It's designed to be flexible to allow for experimentation and testing of new thresholds and methods.

If you need to use this code for experimentation in the southern hemisphere, you'll need to rip off the climdex.gsl code to rotate the year around so that July 1st is treated as January 1st.

See climdex.gsl for more information on what gsl.mode does.

Examples

Run this code

# NOT RUN {
library(PCICt)

## Create a climdexInput object from some data already loaded in and
## ready to go.

## Parse the dates into PCICt.
tmax.dates <- as.PCICt(do.call(paste, ec.1018935.tmax[,c("year",
"jday")]), format="%Y %j", cal="gregorian")
tmin.dates <- as.PCICt(do.call(paste, ec.1018935.tmin[,c("year",
"jday")]), format="%Y %j", cal="gregorian")
prec.dates <- as.PCICt(do.call(paste, ec.1018935.prec[,c("year",
"jday")]), format="%Y %j", cal="gregorian")

## Load the data in.
ci <- climdexInput.raw(ec.1018935.tmax$MAX_TEMP,
ec.1018935.tmin$MIN_TEMP, ec.1018935.prec$ONE_DAY_PRECIPITATION,
tmax.dates, tmin.dates, prec.dates, base.range=c(1971, 2000))

## Create an annual timeseries of the growing season length in days.
gsl <- growing.season.length(ci@data$tavg, ci@date.factors$annual, ci@dates,
                             ci@northern.hemisphere, gsl.mode="GSL") *
       ci@namasks$annual$tavg

## Print these out for testing purposes.
gsl
# }