This vignette demonstrates how to download, process, and calculate
covariates from the Climatology Lab’s TerraClimate
dataset using amadeus functions. Details are provided for
each function’s parameters and outputs. The examples utilize monthly
wind speed data. See https://www.climatologylab.org/wget-terraclimate.html
for full variable names and acronyms. The messages returned by
amadeus functions have been omitted for brevity.
Download
Start by downloading the netCDF data files with
download_data.
dataset_name = "terraclimate": TerraClimate dataset
name.variable = "Wind Speed": wind speed variable name.year = c(2021, 2022): years of interest.directory_to_save = dir: directory to save the
downloaded files.acknowledgement = TRUE: acknowledge that the raw data
files are large and may consume lots of local storage.download = TRUE: download the data files.remove_command = TRUE: remove the temporary command
file used to download the data.hash = TRUE: generate unique SHA-1 hash for the
downloaded files.
dir <- tempdir()
amadeus::download_data(
dataset_name = "terraclimate",
variable = "Wind Speed",
year = c(2021, 2022),
directory_to_save = dir,
acknowledgement = TRUE,
download = TRUE,
remove_command = TRUE,
hash = TRUE
)
[1] "344cddba906371b701f661ccebeef3f427b2d8ec"
Check the downloaded netCDF files.
list.files(dir, recursive = TRUE, pattern = "ws")
[1] "ws/ws_2021.nc" "ws/ws_2022.nc"
Process
Import and process the downloaded netCDF files with
process_covariates.
Parameters:
covariate = "terraclimate": TerraClimate dataset
name.variable = "Wind Speed": wind speed variable name.date = c("2021-12-28", "2022-01-03"): date range of
interest.path = paste0(dir, "/ws"): directory containing the
downloaded files.
ws_process <- amadeus::process_covariates(
covariate = "terraclimate",
variable = "Wind Speed",
date = c("2021-12-28", "2022-01-03"),
path = file.path(dir, "/ws")
)
Check the processed SpatRaster object.
Note Climatology Lab TerraClimate is a monthly dataset,
so the SpatRaster contains two layers for December 2021 and
January 2022.
class : SpatRaster
dimensions : 4320, 8640, 2 (nrow, ncol, nlyr)
resolution : 0.04166667, 0.04166667 (x, y)
extent : -180, 180, -90, 90 (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +ellps=WGS84 +no_defs
sources : ws_2021.nc
ws_2022.nc
varnames : ws (wind speed)
ws (wind speed)
names : ws_202112, ws_202201
unit : m/s, m/s
time (days) : 2021-12-01 to 2022-01-01
terra::plot(ws_process[[1]])
