calc_pv {meteoEVT}

Potential Vorticity (PV)

Description

Calculates the potential vorticity

Usage

calc_pv(
  t_fld,
  u_fld,
  v_fld,
  w_fld,
  lev_p,
  lat = NULL,
  dx = 0.25,
  dy = 0.25,
  zvort_only = FALSE,
  relative = FALSE,
  zvort_fld = NULL,
  mode = "lonlat"
)

Arguments

t_fld

temperature field [K]

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 the vertical vorticity (zvort) should be calculated, FALSE: for the whole vorticity vector, default: FALSE

relative

logical, TRUE: only relative vorticity, FALSE: whole (absolute) vorticity, default: FALSE

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

potential vorticity field [K*m^2/(kg*s)]

Examples

myfile=system.file("extdata", "era5_storm-zeynep.nc", package = "meteoEVT")
data = readin_era5(myfile)
#PV based on all three components
pv=calc_pv(data$temp,data$u,data$v,data$w,data$lev,lat=data$lat)
#PV only based on vertical component
pv_vert=calc_pv(data$temp,data$u,data$v,data$w,lev_p=data$lev,lat=data$lat,zvort_only=TRUE)