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.248253.
\[F=\frac{1}{2}\left\nabla \theta\right[D cos(2\beta)\delta]\] \(F\) 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
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 or ndarray) – The grid spacing(s) in the xdirection. If an array, there should be one item less than the size of u along the applicable axis.
 dy (float or ndarray) – The grid spacing(s) in the ydirection. If an array, there should be one item less than the size of u along the applicable axis.
 dim_order (str or
None
, optional) – The ordering of dimensions in passed in arrays. Can be one ofNone
,'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 is ‘yx’. Can only be passed as a keyword argument, i.e. func(…, dim_order=’xy’).
Returns: (M, N) ndarray – 2D Frontogenesis in [temperature units]/m/s
Notes
If inputs have more than two dimensions, they are assumed to have either leading dimensions of (x, y) or trailing dimensions of (y, x), depending on the value of
dim_order
.Conversion factor to go from [temperature units]/m/s to [temperature units/100km/3h] \(1.08e4*1.e5\)