divergence

metpy.calc.divergence(u, v, *, dx=None, dy=None, x_dim=- 1, y_dim=- 2)

Calculate the horizontal divergence of a vector.

Parameters

• u ((…, M, N) xarray.DataArray or pint.Quantity) – x component of the vector

• v ((…, M, N) xarray.DataArray or pint.Quantity) – y component of the vector

• dx (pint.Quantity, optional) – The grid spacing(s) in the x-direction. If an array, there should be one item less than the size of u along the applicable axis. Optional if xarray.DataArray with latitude/longitude coordinates used as input. Keyword-only argument.

• dy (pint.Quantity, optional) – The grid spacing(s) in the y-direction. If an array, there should be one item less than the size of u along the applicable axis. Optional if xarray.DataArray with latitude/longitude coordinates used as input. Keyword-only argument.

• x_dim (int, optional) – Axis number of x dimension. Defaults to -1 (implying […, Y, X] order). Automatically parsed from input if using xarray.DataArray. Keyword-only argument.

• y_dim (int, optional) – Axis number of y dimension. Defaults to -2 (implying […, Y, X] order). Automatically parsed from input if using xarray.DataArray. Keyword-only argument.

Returns

(…, M, N) xarray.DataArray or pint.Quantity – The horizontal divergence

See also

vorticity

Notes

This implements a numerical version of the typical equation of 2D divergence of a vector in Cartesian coordinates:

\[\nabla \cdot \vec{U} = \frac{\partial u}{\partial x} + \frac{\partial v}{\partial y}\]

Changed in version 1.0: Changed signature from (u, v, dx, dy)

previous

coriolis_parameter

next

exner_function