eqlat

eqlat(lon, lat, q, skip=10, sigma=None)[source]

Get equivalent latitudes corresponding to PV levels evenly sampled from the distribution of sorted PVs. This solves the equation:

\[A = \int_{-\pi/2}^x a^2 2\pi\cos(\phi) d\phi\]

which is the area occupied by PV zonalized below a given contour.

Parameters

  • lon, lat (ndarray) – The longitude and latitude coordinates.

  • q (ndarray) – The potential vorcitiy data. Should be sorted lon x lat x … (this will be changed in a future version).

  • skip (int, optional) – The interval of sorted q from which we select output Q values.

Returns

  • eqlat (ndarray) – The equivalent latitudes. Same shape as q but with longitude dimension replaced with singleton and latitude dimension replaced with the number of equivalent latitudes selected.

  • Q (ndarray) – The associated Q thresholds for the equivalent latitudes. Same shape as eqlat.