Get CHIRTS temperature data

Get daily maximum and minimum temperature data from the "Climate Hazards Group". CHIRTS-daily is a global 2-m temperature product that combines the monthly CHIRTSmax data set with the ERA5 reanalysis to produce routinely updated data to support the monitoring of temperature extreme. Data is currently available from 1983 to 2016. Soon available to near-present.

Usage

get_chirts(object, dates, var, ...)

# Default S3 method
get_chirts(object, dates, var, as.matrix = FALSE, ...)

# S3 method for class 'SpatVector'
get_chirts(object, dates, var, as.raster = TRUE, ...)

# S3 method for class 'SpatRaster'
get_chirts(object, dates, var, as.raster = TRUE, ...)

# S3 method for class 'SpatExtent'
get_chirts(object, dates, var, as.raster = TRUE, ...)

Arguments

object

an object of class data.frame (or any other object that can be coerced to a data.frame), SpatVector, or SpatRaster

dates

a character of start and end dates in that order in the format "YYYY-MM-DD"

var

character, A valid variable from the options: “Tmax”, “Tmin”, “RHum” and “HeatIndex”

...

further arguments passed to terra

as.matrix

logical, returns an object of class matrix

as.raster

logical, returns an object of class SpatRaster

Value

A SpatRaster object if as.raster=TRUE, else matrix, list, or data.frame

Details

Variable description from https://data.chc.ucsb.edu/products/CHIRTSdaily/aaa.Readme.txt

Tmax

Daily average maximum air temperature at 2 m above ground

Tmin

Daily average minimum air temperature at 2 m above ground

RHum

Daily average relative humidity

HeatIndex

Daily average heat index

Additional arguments

interval: supported intervals are “daily”, “pentad”, “dekad”, “monthly”, “2-monthly”, “3-monthly”, and “annual”. Currently hard coded to “daily”.

Examples

if (FALSE) { # interactive()
library("chirps")
library("terra")

# Case 1: input a data frame return a data frame in the long format
dates <- c("2010-12-15","2010-12-31")
lonlat <- data.frame(lon = c(-55.0281,-54.9857),
                     lat = c(-2.8094, -2.8756))

temp1 <- get_chirts(lonlat, dates, var = "Tmax")

# Case 2: input a data frame return a matrix
temp2 <- get_chirts(lonlat, dates, "Tmax", as.matrix = TRUE)

# Case 3: input a raster and return raster
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
temp3 <- get_chirts(v, dates, var = "Tmax", as.raster = TRUE)

# Case 4: input a raster and return raster
temp4 <- get_chirts(v, dates, var = "Tmax", as.matrix = TRUE)
}