| Type: | Package |
| Title: | Download Sea Ice Concentration Data from the NSIDC Climate Data Record |
| Version: | 1.0.0 |
| Description: | Programmatic access to NSIDC's sea ice concentration CDR versions 4 and 5 via its ERDAPP server. Supports caching results and optional fixes for some inconsistencies of the raw files. |
| License: | MIT + file LICENSE |
| Encoding: | UTF-8 |
| Depends: | R (≥ 4.3.0) |
| RoxygenNote: | 7.3.3 |
| Suggests: | here, ncdf4, rcdo, testthat (≥ 3.0.0), vcr |
| Imports: | checkmate, cli, digest, glue, httr2, rlang |
| URL: | https://github.com/eliocamp/icecdr |
| BugReports: | https://github.com/eliocamp/icecdr/issues |
| Config/testthat/edition: | 3 |
| NeedsCompilation: | no |
| Packaged: | 2026-03-10 03:28:36 UTC; user1 |
| Author: | Elio Campitelli 
[cre, aut, cph] |
| Maintainer: | Elio Campitelli <eliocampitelli@gmail.com> |
| Repository: | CRAN |
| Date/Publication: | 2026-03-16 16:20:09 UTC |
icecdr: Download Sea Ice Concentration Data from the NSIDC Climate Data Record
Description
Programmatic access to NSIDC's sea ice concentration CDR versions 4 and 5 via its ERDAPP server. Supports caching results and optional fixes for some inconsistencies of the raw files.
Author(s)
Maintainer: Elio Campitelli eliocampitelli@gmail.com (ORCID) [copyright holder]
See Also
Useful links:
Download sea ice concentration from NSIDC Climate Data Record
Description
This is a low-level function to download data from PolarWatch's ERDDAP server.
Usage
cdr(
date_range = c(NA, NA),
variables = "aice",
hemisphere = c("south", "north"),
resolution = c("monthly", "daily"),
date_stride = 1,
xgrid_range = c(NA, NA),
xgrid_stride = 1,
ygrid_range = c(NA, NA),
ygrid_stride = 1,
version = 5,
format = "nc",
file = NULL,
dir = tempdir(),
use_cache = FALSE
)
Arguments
date_range |
Vector of size two with the start and end dates. Supported formats are:
|
variables |
Character vector with the variables to fetch. Valid values are
Although not all variables are available in all versions and all resolutions.
The |
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". |
date_stride |
Numeric with the temporal stride. A number greater than 1 means to take only the nth date in the series. |
xgrid_range |
Numeric vector of size 2 with the range of the x dimension. |
xgrid_stride |
Numeric with the stride of the x dimension. |
ygrid_range |
Numeric vector of size 2 with the range of the y dimension. |
ygrid_stride |
Numeric with the stride of the y dimension. |
version |
Version of the dataset. Can be 4 or 5. |
format |
Character with the format. |
file |
Character with the file name to use for download. If |
dir |
Directory where to download the file. |
use_cache |
Logical indicating whether to not perform the download if the file already exist. |
Value
Path or vector of paths to the downloaded files.
Examples
## Not run:
cdr(date_range = c("2022-01", "2022-01"),
# Data every 7 days
date_stride = 7,
resolution = "daily",
# Thin the grid by taking every other gridpoint
xgrid_stride = 2,
ygrid_stride = 2,
hemisphere = "north"
)
## End(Not run)
Convenience functions
Description
These are convenience functions to download, daily or monthly
sea ice concentration data from the whole Antarctic or Arctic.
For a more complete low level function, see cdr().
Usage
cdr_antarctic_monthly(
date_range,
variables = "aice",
version = 5,
file = NULL,
dir = tempdir(),
use_cache = FALSE
)
cdr_antarctic_daily(
date_range,
variables = "aice",
version = 5,
file = NULL,
dir = tempdir(),
use_cache = FALSE
)
cdr_arctic_monthly(
date_range,
variables = "aice",
version = 5,
file = NULL,
dir = tempdir(),
use_cache = FALSE
)
cdr_arctic_daily(
date_range,
variables = "aice",
version = 5,
file = NULL,
dir = tempdir(),
use_cache = FALSE
)
Arguments
date_range |
Vector of size two with the start and end dates. Supported formats are:
|
variables |
Character vector with the variables to fetch. Valid values are
Although not all variables are available in all versions and all resolutions.
The |
version |
Version of the dataset. Can be 4 or 5. |
file |
Character with the file name to use for download. If |
dir |
Directory where to download the file. |
use_cache |
Logical indicating whether to not perform the download if the file already exist. |
Value
A string vector with the location of the downloaded files
Examples
## Not run:
cdr_antarctic_monthly(c("2022-01", "2022-01"))
## End(Not run)
Minor fixes to CDR files.
Description
cdr_fix() "fixes" some inconsistencies in the raw data.
It standardised variable names between versions and temporal resolutions and
adds projection information to the grid definition so CDO can compute the
area of each gridpoint to compute weighted means or area integrals.
Both require the rcdo package and CDO installed.
Usage
cdr_fix(files, fix = c("names", "grid"))
cdr_fix_names(files)
cdr_fix_grid(files)
Arguments
files |
Path to the files. |
fix |
Character vector with the fixes to implement. |
Details
cdr_fix_names() and cdr_fix_grid() are aliases for cdr_fix(fix = "names")
and cdr_fix(fix = "grid"), respectively.
Using cdr_fix() to fix both at the same time is more efficient as it
recreates each file only once.
Value
The path to the modified files.
Examples
## Not run:
cdr_antarctic_monthly(c("2022-01", "2022-01")) |>
cdr_fix()
## End(Not run)