loadSnowData24km: NSIDC Snow Model Functions

In ABoVE-AotM/above: Functions and methods for the Animals on the Move project of the Arctic Boreal Vulnerability Experiment (ABoVE - NASA).

Description

This function downloads 24km x 24km snow ice data from the NSIDS repository (ftp://sidads.colorado.edu/pub/DATASETS/NOAA/G02156/) and processes the data. An additonal function plotSnowData conveniently maps the output.

Usage

loadSnowData24km(
  year,
  day,
  filename = NULL,
  directory = ".",
  plot = FALSE,
  northamerica = TRUE,
  water = FALSE,
  ...
)

Arguments

plot	whether to plot the map.
northamerica	whether to limit to North America
water	whether or not to include the open water category
...	additional arguments to pass to polygon function
year, day	of data to download
filename, directory	of the ascii raw snow file if raw data are already downloaded

Value

a data frame that contains:

snow

snow coverage: 1 = open water, 2 = no snow, 3 = sea ice, 4 = snow

area

of grid cell, in km^2

lon,lat

longitude and latitude - midpoint of grid cell

lon.ll,lon.ul,lon.ur,lon.lr

longitudes of corners of grid cell

lat.ll,lat.ul,lat.ur,lat.lr

latitudes of corners of grid cell

References

National Ice Center. 2008, updated daily. IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km Resolutions, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N52R3PMC. [Date Accessed].

Examples

#  The output is equivalent to the saved examples in \code{\link{snow24km}}
snow.data <- loadSnowData24km(2011, 16)
plotSnowData(snow.data); title("Jan 16, 2011")

ABoVE-AotM/above documentation built on May 28, 2020, 6:08 a.m.