bio3: bio3: Calculates isothermality

In ilyamaclean/climvars: Functions for calculating biologically meaningful climate variables

Description

bio3 is used to calculate isothermality (day-to-night temperature oscillations relative to annual oscillations).

Usage

bio3(temps, tme, method = "")

Arguments

temps	a vector of temperatures, normally for one year (see details).
tme	a POSIXlt object representing the date and time of each temps value.
method	An optional character string describing the method used to calculate isothermality. Options include "anuclimmean", "anuclimmaxmin" or unspecified (see details).

Details

If method is "anuclimmean", bio3 is calculated using "anuclim" method. Temperatures are aggregated by month and spline intepolated to weekly before mean diurnal temperature range is calculated, replicating the method used by http://www.worldclim.org/.

If method is "anuclimaxmin", bio3 is calculated using "anuclimmaxmin" method. Maximum and minimum monthly temperatues are spline interpolated to a weekly time period and range is calculated from the maximum and minimum mean weekly temperature values.

If using method "anuclimmean" or "anuclimmaxmin" and data spans more than one year, data are aggregated by unique month irrespective of year and one value returned.

If method is left unspecified, bio3 is calculated using the mean of daily maximum and minimum temperature. If data spans more than one year, data are aggregated by unique month irrespective of year and one value returned. If method is unspecified, bio7 is calculated using the maximum temperature value for the year.If data spans more than one year, bio7 calculations are performed on all data and single value returned.

Value

a single numeric value representing isothermality for each year.

See Also

bio2() and bio7() for calculating diurnal and annual temperature ranges. tmecreate() for creating a 'POSIXlt' object.

Examples

temps <- 10 * sin(c(0:1459) / (pi * 150)) + rnorm(1460)
tme <- tmecreate(2010, 24)
plot(temps~as.POSIXct(tme), type = "l", xlab = "Month", ylab = "Temperature")
bio3(temps, tme)
bio3(temps, tme, method = "anuclimmean")
bio3(temps, tme, method = "anuclimmaxmin")

ilyamaclean/climvars documentation built on June 19, 2019, 2:22 p.m.