chillR (version 0.75)

download_baseline_cmip6_ecmwfr: Download historical CMIP6 Data via the ecwfr package

Description

Accesses the CMIP6 data of the Copernicus API via the ecmwfr package. Saves the downloaded files as .zip objects in the specified path in a subfolder with the coordinates of the downloaded area as subfolder name. You can either specify the GCMs by name or you can take all GCMs for which you downloaded climate change scenarios (model = "match_downloaded").

Usage

download_baseline_cmip6_ecmwfr(
  area,
  user,
  key,
  model = "match_downloaded",
  service = "cds",
  frequency = "monthly",
  variable = c("Tmin", "Tmax"),
  year_start = 1986,
  year_end = 2014,
  month = 1:12,
  sec_wait = 3600,
  n_try = 10,
  update_everything = FALSE,
  path_download = "cmip6_downloaded"
)

Value

NULL, the downloaded files are saved in the stated directory

Arguments

area

numeric vector of length 4. Sets the spatial boundaries of the downloaded data. Coordinates are supplied in the following format: c(maximum latitude, minimum longitude, minimum latitude, maximum longitude), which corresponds to the northern extent, western extent, southern extent and eastern extent of the area of interest.

user

a character, user name from the Copernicus climate data store. See 'Details' for more information.

key

a character. Can be found just beneath the user id on the profile when registering for the Copernicus website. Should be provided as a character (so in quotation marks).

model

character, by default "match_downloaded". Looks up the already downloaded GCMs for the climate change scenarios of the "download_cmip6_ecmwfr()" function. You can also specify the models by name as a vector.

service

character, by default 'cds'. Decides which database is used. For more details see in the documentation of ecmwfr::wf_set_key().

frequency

character, can be either 'daily' or 'monthly'. Sets if the downloaded CMIP6 data is in daily or monthly format.

variable

vector of characters, decides which variables get downloaded. Currently, the options "Tmin" (Daily minimum temperature in degree centigrade), "Tmax" (Daily maximum temperature in degree centigrade) and "Prec" (Daily sum of precipitation in mm) are the only valid options.

year_start

numeric, earliest year for downloaded CMIP6 data. By default set to 1985.

year_end

numeric, latest year for downloaded CMIP6 data. By default set to 2014.

month

numeric vector, sets for which months data should be downloaded. By default set to 1:12.

sec_wait

numeric, sets the maximum waiting time per requested file. By default is 3600, so 1 hour.

n_try

numeric, number of repeated calls for the API. For more information see 'Details'.

update_everything

logical, by default set to FALSE. When set to FALSE, scenarios with matching names that have already been downloaded are skipped. If set to TRUE, then files are downloaded regardless if a file with the same name is already present.

path_download

character, sets the path for the download of the CMIP6 file. If not already present, then a new folder will be created. The path is relative to the working directory.

Author

Lars Caspersen

Details

Registering for cds.climate.coperincus.eu: https://cds.climate.copernicus.eu/cdsapp#!/home

Examples

if (FALSE) {
# example with one specified GCM 
download_baseline_cmip6_ecmwfr(
    area = c(55, 5.5, 47, 15.1),
    user = 'write user id here',
    key = 'write key here',
    model = 'AWI-CM-1-1-MR',
    frequency = 'monthly', 
    variable = c('Tmin', 'Tmax'))
 }