evapoRe (version 1.0.1)

calc_rn: Calculate Net Radiation (Rn)

Description

Computes net radiation (Rn) based on solar radiation, temperature, and elevation.

Usage

calc_rn(tmax, tmin, rs, elevation, albedo = 0.23, x = NULL)
# S4 method for missing,missing,missing,missing,missing
calc_rn(x)
# S4 method for Raster,Raster,Raster,Raster,ANY
calc_rn(tmax, tmin, rs, elevation, albedo = 0.23, x = NULL)
# S4 method for character,character,character,character,ANY
calc_rn(tmax, tmin, rs, elevation, albedo = 0.23, x = NULL)

Value

RasterBrick or data.table of net radiation values (MJ m-2 day-1)

Arguments

tmax

Raster* object or file path for maximum temperature (°C)

tmin

Raster* object or file path for minimum temperature (°C)

rs

Raster* object or file path for solar radiation (MJ m-2 day-1)

elevation

Raster* object or file path for elevation (m)

albedo

Numeric, Raster*, or file path for albedo (optional, default = 0.23)

x

A `data.table` with columns: "lon", "lat", "date", "rs", "tmax", "tmin", "elevation", and optionally "albedo"

Details

For raster inputs, provide individual raster objects or file paths for `tmax`, `tmin`, `rs`, `elevation`, and optionally `albedo`. For `data.table` input, provide a single `data.table` with columns: "lon", "lat", "date", "rs", "tmax", "tmin", "elevation", and optionally "albedo".

Examples

# \donttest{
# Example using Raster* input
if (requireNamespace("raster", quietly = TRUE)) {
  tmax_path <- file.path(tempdir(), "tmax.nc")
  tmin_path <- file.path(tempdir(), "tmin.nc")
  rs_path   <- file.path(tempdir(), "rs.nc")
  elev_path <- file.path(tempdir(), "elevation.nc")

  if (file.exists(tmax_path) && file.exists(tmin_path) &&
      file.exists(rs_path) && file.exists(elev_path)) {
    tmax <- raster::brick(tmax_path)
    tmin <- raster::brick(tmin_path)
    rs   <- raster::brick(rs_path)
    elev <- raster::brick(elev_path)

    rn <- calc_rn(tmax = tmax, tmin = tmin, rs = rs, elevation = elev)
  }
}

# Example using data.table input
if (requireNamespace("data.table", quietly = TRUE)) {
  dt <- data.table::data.table(
    lon = c(10.0, 10.5),
    lat = c(45.0, 45.5),
    date = as.Date(c("2001-06-01", "2001-06-01")),
    tmax = c(28.3, 27.6),
    tmin = c(14.1, 13.5),
    rs = c(22.5, 21.9),
    elevation = c(400, 420)
  )
  rn_dt <- calc_rn(x = dt)
}
# }