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Get raw CHIRTS raster data

Source: R/get_chirts_raw.R
get_chirts_raw.Rd

Download CHIRTS daily temperature data in its original raster format, from CHIRTS-daily (default) or CHIRTS-ERA5.

Usage

get_chirts_raw(
  dates,
  var,
  product = c("CHIRTS-daily", "CHIRTS-ERA5"),
  resolution = 0.05,
  coverage = "global",
  interval = "daily",
  format = "tifs",
  version = "1.0",
  use_vsicurl = TRUE,
  verbose = FALSE,
  ...
)

Arguments

dates

Character or Date vector "YYYY-MM-DD", with one date for a single day or two dates for the start and end of the period.

var

Character. CHIRTS variable. Supported values are "Tmax", "Tmin", "RHum", and "HeatIndex". CHIRTS-ERA5 has "Tmax" and "Tmin" only.

product

Character. "CHIRTS-daily" (default, 1983 to 2016) or "CHIRTS-ERA5" (1980 to near present).

resolution

Numeric. Spatial resolution. Default is 0.05. CHIRTS-daily only.

coverage

Character. Spatial coverage. Default is "global". CHIRTS-daily only.

interval

Character. Temporal interval. Default is "daily". Currently retained for API consistency.

format

Character. File format folder. Default is "tifs". CHIRTS-daily only.

version

Character or numeric. CHIRTS-daily version. Default is "1.0".

use_vsicurl

Logical. If TRUE, prepends "/vsicurl" to remote URLs.

verbose

Logical. If TRUE, prints the URLs used.

...

Additional arguments reserved for future use.

Value

A SpatRaster with one layer per day.

Details

This function returns CHIRTS raster layers as a SpatRaster without extracting values, reshaping the data, or converting it to a data frame.

CHIRTS-daily (Climate Hazards Center Infrared Temperature with Stations) is a quasi-global (60°S to 70°N), high-resolution (0.05 degrees) dataset of daily maximum and minimum temperatures, relative humidity and heat index covering 1983-2016. It combines monthly CHIRTS temperature fields with daily temperature variability from the ERA5 reanalysis. Daily minimum temperatures are derived using the ERA5 diurnal temperature range. See https://www.chc.ucsb.edu/data/chirtsdaily.

CHIRTS-ERA5 is a quasi-global (60°S to 70°N), high-resolution (0.05 degrees) dataset of daily maximum and minimum temperatures from 1980 to near present. It combines CHIRTS (1983-2016) with the regularly updated ERA5 reanalysis, downscaled and bias-corrected relative to CHIRTS. It is an experimental CHC product. Users should cite "CHIRTS-ERA5 Data Repository. https://doi.org/10.15780/G2F08J. Data accessed on [DATE]." See https://www.chc.ucsb.edu/data/chirts-era5.

Messages: each request states what it downloads, here daily temperature or humidity from CHIRTS, with the period, so it is not mistaken for rainfall from get_chirps. Set options(chirps.quiet = TRUE) to hide these messages.

References

Verdin, A., Funk, C., Peterson, P., Landsfeld, M., Tuholske, C., and Grace, K. (2020). Development and validation of the CHIRTS-daily quasi-global high-resolution daily temperature data set. Scientific Data, 7, 303. doi:10.1038/s41597-020-00643-7

Funk, C., Peterson, P., Peterson, S., Shukla, S., Davenport, F., Michaelsen, J., et al. (2019). A High-Resolution 1983-2016 Tmax Climate Data Record Based on Infrared Temperatures and Stations by the Climate Hazards Center. Journal of Climate, 32, 5639-5658. doi:10.1175/JCLI-D-18-0698.1

Climate Hazards Center (CHC). CHIRTS-ERA5 Data Repository. doi:10.15780/G2F08J

Examples

if (interactive()) {
  tmax = get_chirts_raw(dates = c("2015-01-01", "2015-01-31"),
                        var = "Tmax")

  # recent dates from CHIRTS-ERA5
  tmin = get_chirts_raw(dates = c("2024-01-01", "2024-01-31"),
                        var = "Tmin",
                        product = "CHIRTS-ERA5")
}