Read data from derived sea ice data products.

Derived sea ice data is read from files managed by derivicefiles.

readderivice(
  date,
  time.resolution = c("daily"),
  product = c("time_since_melt"),
  xylim = NULL,
  latest = TRUE,
  returnfiles = FALSE,
  ...,
  inputfiles = NULL
)

Arguments

date

date or dates of data to read, see Details

time.resolution

time resoution data to read, daily or monthly

product

choice of sea ice product, see Details

xylim

spatial extents to crop from source data, can be anything accepted by extent

latest

if TRUE and date input missing, return the latest time available, otherwise the earliest

returnfiles

ignore options and just return the file names and dates

...

passed to brick, primarily for filename

inputfiles

input the file set to avoid rescanning that (for extract point-in-time)

Value

raster object

Details

Currently available products are

Dates are matched to file names by finding the nearest match in time within a short duration. If date is greater than length 1 then the sorted set of unique matches is returned.

time_since_melt

32767 (treated as missing data)

32766 = land

32765 = open-ocean zone

-32768 = ice that hasn't melted during the data period

In terms of missing data 32767, in the nc file, so should be NA once read into R): these are either open water in the sea ice zone that hasn't re-frozen during the data period, or missing sea ice data that couldn't be interpolated.

See also

derivicefiles for details on the repository of data files, raster for the return value