# montgomery_streamfunction¶

metpy.calc.montgomery_streamfunction(height, temperature)[source]

Compute the Montgomery Streamfunction on isentropic surfaces.

The Montgomery Streamfunction is the streamfunction of the geostrophic wind on an isentropic surface. This quantity is proportional to the geostrophic wind in isentropic coordinates, and its gradient can be interpreted similarly to the pressure gradient in isobaric coordinates.

Parameters
Returns

stream_func (pint.Quantity or xarray.DataArray)

Notes

The formula used is that from [Lackmann2011] p. 69.

$\Psi = gZ + C_pT$
• $$\Psi$$ is Montgomery Streamfunction

• $$g$$ is avg. gravitational acceleration on Earth

• $$Z$$ is geopotential height of the isentropic surface

• $$C_p$$ is specific heat at constant pressure for dry air

• $$T$$ is temperature of the isentropic surface

get_isentropic_pressure, dry_static_energy