Q-Vectors

Q-Vectors

Usage

Q_vector(zg, ta, lon, lat, pa_pl, sigma = 1, nthreads = 1)

Arguments

zg

geopotential [lon, lat, lev, time] on pressure levels (m^2/s^2).

ta

air temperature [lon, lat, lev, time] on pressure levels (K).

lon

longitude coordinates [lon] (degrees east).

lat

latitude coordinates [lat] (degrees north).

pa_pl

pressure levels [lev] (hPa).

sigma

static stability at pressure level. Default 1.

nthreads

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

Value

A list with two 4D arrays:

• Q1: zonal Q-vector component [lon, lat, lev, time] in m^2 kg^-1 s^-1.

• Q2: meridional Q-vector component [lon, lat, lev, time] in m^2 kg^-1 s^-1.

#' @examples data("ERA5_pl") zg <- ERA5_pl$z ta <- ERA5_pl$ta lon <- ERA5_pl$lon lat <- ERA5_pl$lat pa_pl <- ERA5_pl$plev/100

res <- Q_vector(zg, ta, lon, lat, pa_pl)

Details

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

References

Bluestein, H. B., 1992: Principles of Kinematics and Dynamics. Vol. 1, Synoptic-Dynamic Meteorology in Midlatitudes. Oxford University Press, 448 pp.