Download sea ice index data. — sea_ice

The NSIDC sea ice index product provides computed sea ice extent for each hemisphere on daily and monthly resolution.

Usage

sea_ice_index(
  hemisphere = c("south", "north"),
  resolution = c("monthly", "daily"),
  file = NULL,
  dir = tempdir(),
  use_cache = TRUE
)

Arguments

hemisphere: Character with the hemisphere to download. Can be either "south" or "north".
resolution: Character with the temporal resolution. Can be either "monthly" or "daily".
file: Character with the file name to use for download. If NULL, the file name will be constructed by hashing the request URL. Requests consisting in more than one file will append a number.
dir: Directory where to download the file.
use_cache: Logical indicating whether to not perform the download if the file already exist.

Value

The route to the file name.

Details

The returned files are not the raw files, but contain minor format modifications for ease of use. Instead of year and month columns, there is a single time column. Instead of a region column with "S" or "N" values, there is a hemisphere column with values "south" and "north" (for consistency with the function arguments). Column names are all in lower case and are the same for the daily and monthly products, except for an area column that is only available in the monthly product. Area and extent values are expressed in km^2.

Examples

if (FALSE) { # \dontrun{
sea_ice_index("south", "monthly")
} # }