calc_enstrophy {meteoEVT}

Enstrophy density

Description

Calculates the enstrophy density (vorticity squared) either in 2d or 3d

Usage

calc_enstrophy(
  u_fld,
  v_fld,
  w_fld = NULL,
  lev_p,
  lat = NULL,
  dx = 0.25,
  dy = 0.25,
  zvort_only = TRUE,
  relative = TRUE,
  zvort_fld = NULL,
  mode = "lonlat"
)

Arguments

u_fld

zonal velocity field [m/s]

v_fld

meridional velocity field [m/s]

w_fld

vertical velocity field [m/s]

lev_p

vector containing pressure levels [Pa]

lat

vector containing latitude

dx

x resolution in the corresponding unit (e.g. 0.25 degree for ERA5 with mode='lonlat' or e.g. 1000 m in cartesian coordinates with mode='cartesian')

dy

y resolution in the corresponding unit (e.g. 0.25 degree for ERA5 with mode='lonlat' or e.g. 1000 m in cartesian coordinates with mode='cartesian')

zvort_only

logical, TRUE: if only 2d enstrophy (based on z-vorticity) should be calculated, FALSE: for 3d enstrophy (based on 3d vorticity), default: TRUE

relative

logical, TRUE: only relative vorticity, FALSE: whole (absolute) vorticity should be used for calculation of enstrophy, default: TRUE

zvort_fld

optional zvort field (if e.g., zvort is directly taken from ERA5 and not calculated separately)

mode

use 'lonlat' if the data is given on a lon-lat-grid or 'cartesian' if the data is given on an equidistant cartesian grid

Value

enstrophy density field [1/s^2]

Examples

myfile=system.file("extdata", "era5_storm-zeynep.nc", package = "meteoEVT")
data = readin_era5(myfile)
#3d enstropy
ens3d=calc_enstrophy(data$u,data$v,data$w,data$lev,lat=data$lat)
#2d enstropy as scalar
ens2d=calc_enstrophy(data$u,data$v,lev_p=data$lev,lat=data$lat,zvort_only=TRUE)