WaveFlux: Calculate wave-activity flux

In metR: Tools for Easier Analysis of Meteorological Fields

Calculate wave-activity flux

Description

Calculate wave-activity flux

Usage

WaveFlux(gh, u, v, lon, lat, lev, g = 9.81, a = 6371000)

Arguments

gh	Geopotential Height Anomaly (unit: gpm or m). The deviation of the geopotential height from the climatological mean (z' = z - \bar{z}). It is used to compute the perturbation geostrophic streamfunction: \psi' = \frac{g}{f}z'.
u	Mean Zonal Wind (unit: m/s). The background basic flow (\bar{u}), usually representing the long-term climatological mean zonal velocity.
v	Mean Meridional Wind (unit: m/s). The background basic flow (\bar{v}), usually representing the long-term climatological mean meridional velocity.
lon	Numeric vector of longitudes (unit: degrees).
lat	Numeric vector of latitudes (unit: degrees).
lev	The pressure level of the data (unit: hPa). Used for the vertical scaling factor p/1000 in the T-N flux formula.
g	Standard gravity acceleration (default: 9.81 m/s^2).
a	Earth's mean radius (default: 6,371,000 m).

Details

The function computes the horizontal components (W_x, W_y) of the phase-independent wave activity flux.

Note on Units: Ensure that gh is provided as Geopotential Height (in meters or gpm). If your input data is Geopotential (\Phi, in m^2/s^2, common in ERA5 raw data), you must divide it by gravity (g) before passing it to this function.

Value

A data.table containing the calculated wave activity flux components:

w.x	Zonal component of the Wave Activity Flux.
w.y	Meridional component of the Wave Activity Flux.

References

Takaya, K. and H. Nakamura, 2001: A Formulation of a Phase-Independent Wave-Activity Flux for Stationary and Migratory Quasigeostrophic Eddies on a Zonally Varying Basic Flow. J. Atmos. Sci., 58, 608–627, \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1175/1520-0469(2001)058<0608:AFOAPI>2.0.CO;2")}
Adapted from https://github.com/marisolosman/Reunion_Clima/blob/master/WAF/Calculo_WAF.ipynb

See Also

Other meteorology functions: Derivate(), EOF(), GeostrophicWind(), thermodynamics, waves

metR documentation built on Oct. 8, 2026, 9:17 a.m.