# absolute_momentum¶

metpy.calc.absolute_momentum(u, v, index='index')[source]

Calculate cross-sectional absolute momentum (also called pseudoangular momentum).

As given in [Schultz1999], absolute momentum (also called pseudoangular momentum) is given by:

$M = v + fx$

where $$v$$ is the along-front component of the wind and $$x$$ is the cross-front distance. Applied to a cross-section taken perpendicular to the front, $$v$$ becomes the normal component of the wind and $$x$$ the tangential distance.

If using this calculation in assessing symmetric instability, geostrophic wind should be used so that geostrophic absolute momentum $$\left(M_g\right)$$ is obtained, as described in [Schultz1999].

Parameters
Returns

absolute_momentum (xarray.DataArray) – Absolute momentum

Notes

The coordinates of u and v must match.

Changed in version 1.0: Renamed u_wind, v_wind parameters to u, v