Learn R Programming

FedData (version 2.5.7)

get_daymet: Download and crop the 1-km DAYMET daily weather dataset.

Description

get_daymet returns a RasterBrick of weather data cropped to a given template study area.

Usage

get_daymet(template, label, elements = NULL, years = NULL,
  raw.dir = "./RAW/DAYMET", extraction.dir = paste0("./EXTRACTIONS/",
  label, "/DAYMET"), force.redo = F)

Value

A named list of RasterBricks of weather data cropped to the extent of the template.

Arguments

template

A Raster* or Spatial* object to serve as a template for cropping.

label

A character string naming the study area.

elements

A character vector of elements to extract.
The available elements are:
dayl = Duration of the daylight period in seconds per day. This calculation is based on the period of the day during which the sun is above a hypothetical flat horizon.
prcp = Daily total precipitation in millimeters per day, sum of all forms converted to water-equivalent. Precipitation occurrence on any given day may be ascertained.
srad = Incident shortwave radiation flux density in watts per square meter, taken as an average over the daylight period of the day. NOTE: Daily total radiation (MJ/m2/day) can be calculated as follows: ((srad (W/m2) * dayl (s/day)) / l,000,000)
swe = Snow water equivalent in kilograms per square meter. The amount of water contained within the snowpack.
tmax = Daily maximum 2-meter air temperature in degrees Celsius.
tmin = Daily minimum 2-meter air temperature in degrees Celsius.
vp = Water vapor pressure in pascals. Daily average partial pressure of water vapor.

years

A numeric vector of years to extract.

raw.dir

A character string indicating where raw downloaded files should be put. The directory will be created if missing. Defaults to './RAW/DAYMET/'.

extraction.dir

A character string indicating where the extracted and cropped DEM should be put. The directory will be created if missing. Defaults to './EXTRACTIONS/DAYMET/'.

force.redo

If an extraction for this template and label already exists, should a new one be created?

Examples

Run this code
if (FALSE) {
# Extract data for the Village Ecodynamics Project 'VEPIIN' study area:
# http://village.anth.wsu.edu
vepPolygon <- polygon_from_extent(raster::extent(672800,740000,4102000,4170000),
     proj4string='+proj=utm +datum=NAD83 +zone=12')

# Get the DAYMET (North America only)
# Returns a list of raster bricks
DAYMET <- get_daymet(template=vepPolygon,
                     label='VEPIIN',
                     elements = c('prcp','tmin','tmax'),
                     years = 1980:1985)

# Plot with raster::plot
plot(DAYMET$tmin$X1985.10.23)
}

Run the code above in your browser using DataLab