Ktotal {raytracing}

Calculates Total Wavenumber for Rossby Waves (K)

Description

Ktotal ingests the time-mean zonal wind (u) and calculates the Rossby wavenumber (K) (non-zero frequency waves) in mercator coordinates. In this code Ktotal is used to distinguish the total wavenumber (K) from zonal wave number (k). For stationary Rossby Waves, please see Ks. Ktotal returns a list with K in mercator coordinates (ktotal_m).

Usage

Ktotal(
  u,
  lat = "lat",
  lon = "lon",
  uname = "uwnd",
  cx,
  ofile,
  a = 6371000,
  plots = FALSE,
  show.warnings = FALSE
)

Arguments

u

String indicating the input data filename. The file to be passed consists in a netCDF file with only time-mean zonal wind at one pressure level, latitude in ascending order (not a requisite), and longitude from 0 to 360. It is required that the read dimensions express longitude (in rows) x latitude (in columns). u also can be a numerical matrix with time-mean zonal wind at one pressure level, latitude in ascending order (not a requisite), and longitude from 0 to 360. It is required that the read dimensions express longitude (in rows) x latitude (in columns).

lat

String indicating the name of the latitude field. If u is a matrix, lat must be numeric

lon

String indicating the name of the longitude field.If u is a matrix, lon must be numeric from 0 to 360.

uname

String indicating the variable name field

cx

numeric. Indicates the zonal phase speed. Must be greater than zero. For cx equal to zero (stationary waves see Ks)

ofile

String indicating the file name for store output data. If missing, will not return a netCDF file

a

Numeric indicating the Earth's radio (m)

plots

Logical, if TRUE will produce filled.countour plots

show.warnings

Logical, if TRUE will warns about NaNs in sqrt(<0)

Value

list with one vector (lat) and 1 matrix (ktotal_m)

Examples

{
# u is NetCDF and lat and lon characters
input <- system.file("extdata",
                     "uwnd.mon.mean_200hPa_2014JFM.nc",
                      package = "raytracing")
Ktotal <- Ktotal(u = input, cx = 6, plots = TRUE)
cores <- c("#ff0000","#ff5a00","#ff9a00","#ffce00","#f0ff00")
graphics::filled.contour(Ktotal$ktotal_m[, -c(1:5, 69:73)] ,
                         col = rev(colorRampPalette(cores, bias = 0.5)(20)),
                         main = "K")
}