frontogenesis

metpy.calc.frontogenesis(thta, u, v, dx, dy, dim_order='yx')[source]

Calculate the 2D kinematic frontogenesis of a temperature field.

The implementation is a form of the Petterssen Frontogenesis and uses the formula outlined in [Bluestein1993] pg.248-253.

\[F=\frac{1}{2}\left|\nabla \theta\right|[D cos(2\beta)-\delta]\]
  • \(F\) is 2D kinematic frontogenesis
  • \(\theta\) is potential temperature
  • \(D\) is the total deformation
  • \(\beta\) is the angle between the axis of dilitation and the isentropes
  • \(\delta\) is the divergence

Notes

Assumes dim_order=’yx’, unless otherwise specified.

Parameters:
  • thta ((M, N) ndarray) – Potential temperature
  • u ((M, N) ndarray) – x component of the wind
  • v ((M, N) ndarray) – y component of the wind
  • dx (float) – The grid spacing in the x-direction
  • dy (float) – The grid spacing in the y-direction
  • dim_order (str or None, optional) – The ordering of dimensions in passed in arrays. Can be one of None, 'xy', or 'yx'. 'xy' indicates that the dimension corresponding to x is the leading dimension, followed by y. 'yx' indicates that x is the last dimension, preceded by y. None indicates that the default ordering should be assumed, which will change in version 0.6 from ‘xy’ to ‘yx’. Can only be passed as a keyword argument, i.e. func(…, dim_order=’xy’).
Returns:

(M, N) ndarray – 2D Frotogenesis in [temperature units]/m/s

Conversion factor to go from [temperature units]/m/s to [tempature units/100km/3h] \(1.08e4*1.e5\)