wrf.uvmet¶

wrf.uvmet(u, v, lat, lon, cen_long, cone, meta=True, units=u'm s-1')¶

Return the u,v components of the wind rotated to earth coordinates.

The leftmost dimension of the returned array represents two different quantities:

return_val[0,...] will contain U

return_val[1,...] will contain V

This is the raw computational algorithm and does not extract any variables from WRF output files. Use wrf.getvar() to both extract and compute diagnostic variables.

Parameters:

u (xarray.DataArray or numpy.ndarray) –
The u component of the wind [m s-1]. This variable can be staggered or unstaggered, but must be at least two dimensions. If staggered, the rightmost dimensions are south_north x west east.

If staggered, the rightmost dimensions are south_north x west_east_stag.

Note

This variable must be supplied as a xarray.DataArray in order to copy the dimension names to the output. Otherwise, default names will be used.
v (xarray.DataArray or numpy.ndarray) –
The v component of the wind [m s-1]. This variable can be staggered or unstaggered, but must be at least two dimensions. If staggered, the rightmost dimensions are south_north x west east.

IF staggered, the rightmost dimensions are south_north_stag x west_east.
lat (xarray.DataArray or numpy.ndarray) –
The latitude array.

This array can either be:
- two-dimensional of size south_north x west_east.
- multi-dimensional with the same number of dimensions as u and v, but with rightmost dimensions south_north x west_east and the same leftmost dimensions as u and v
- multi-dimensional with one fewer dimensions as u and v, with rightmost dimensions south_north x west_east and the same leftmost dimensions as u and v, minus the third-from-the-right dimension of u and v.
Note

This variable must also be supplied as a xarray.DataArray in order to copy the dimension names to the output. Otherwise, default names will be used.
lon (xarray.DataArray or numpy.ndarray) –
The longitude array.

This array can either be:
- two-dimensional of size south_north x west_east.
- multi-dimensional with the same number of dimensions as u and v, but with rightmost dimensions south_north x west_east and the same leftmost dimensions as u and v
- multi-dimensional with one fewer dimensions as u and v, with rightmost dimensions south_north x west_east and the same leftmost dimensions as u and v, minus the third-from-the-right dimension of u and v.
cen_long (float) – The standard longitude for the map projection.

cone (float) –

The cone factor used for the map project. IF the projection is not a conic projection, the cone is simply 1.0. For conic projections, the cone factor is given by:

if((fabs(true_lat1 - true_lat2) > 0.1) and
(fabs(true_lat2 - 90.) > 0.1)):
    cone = (log(cos(true_lat1*radians_per_degree))
    - log(cos(true_lat2*radians_per_degree)))

    cone = (cone /
    (log(tan((45.-fabs(true_lat1/2.))*radians_per_degree))
    - log(tan((45.-fabs(true_lat2/2.))*radians_per_degree))))
else:
    cone = sin(fabs(true_lat1)*radians_per_degree)

meta (bool) – Set to False to disable metadata and return numpy.ndarray instead of xarray.DataArray. Default is True.
units (str) – The desired units. Refer to the getvar() product table for a list of available units for ‘uvmet’. Default is ‘m s-1’.

Warning

The input arrays must not contain any missing/fill values or numpy.nan values.

Returns:	The u,v components of the wind rotated to earth coordinates. The leftmost dimension size is 2, for u and v. If xarray is enabled and the meta parameter is True, then the result will be an `xarray.DataArray` object. Otherwise, the result will be a `numpy.ndarray` object with no metadata.
Return type:	`xarray.DataArray` or `numpy.ndarray`