The module pyvortex consists of functions to calculate the equivalent latitude and edge of a polar vortex using Nash criteria.

pip install pyvortex

install the latest version using

pip install git+https://github.com/pankajkarman/pyvortex.git

Latest documentation is available here.

pyvortex is easy to use. Just import:

import pyvortex as vr

Instantiate the PolarVortex class using:

pol = PolarVortex(pv, uwind, hemisphere='north')

Get equivalent latitude for the provided vorticity data as:

eql = pol.get_eql()

If you want to get both equivalent latitude and Vortex edge, just use:

eql = pol.get_edge(min_eql=30)

Example:

Instantiate the PolarVortex class using:

pol = PolarVortex(pv, uwind, hemisphere='south')
eql = pol.get_edge(min_eql=30)

By default, equivalent latitude and vortex edge are returned as positive latitude magnitudes. If you want signed Southern Hemisphere output, use:

pol = PolarVortex(pv, uwind, hemisphere='south', signed_output=True)
eql = pol.get_edge(min_eql=30)

This returns Southern Hemisphere equivalent latitudes and edges as negative values.

Example: