Relative Vorticity

This function computes the relative vorticity of a wind field, given the zonal and meridional wind components.

Usage

relative_vorticity(ua, va, lon, lat, nthreads = 1)

Arguments

ua

zonal wind component [lon, lat, lev, time] on pressure levels (m/s).

va

meridional wind component [lon, lat, lev, time] on pressure levels (m/s).

lon

longitude coordinates [lon] (degrees east).

lat

latitude coordinates [lat] (degrees north).

nthreads

an integer specifying the number of threads to use for computation (OpenMP). Default is 1.

Value

the computed relative vorticity [lon, lat, lev, time] (1/s).

Details

The derivatives are approximated using finite differences. Grid spacing is computed using Haversine forumla.

Examples

data("ERA5_pl")
ua <- ERA5_pl$ua
va <- ERA5_pl$va
lon <- ERA5_pl$lon
lat <- ERA5_pl$lat

rv <- relative_vorticity(ua, va,
  lon, lat,
  nthreads = 2
)