xarray.Dataset.regridder.horizontal

Dataset.regridder.horizontal(data_var, output_grid, tool='xesmf', **options)

Apply horizontal regridding to data_var of the current xr.Dataset to output_grid.

When might Regrid2 be preferred over xESMF?

If performing conservative regridding from a high/medium resolution lat/lon grid to a coarse lat/lon target, Regrid2 may provide better results as it assumes grid cells with constant latitudes and longitudes while xESMF assumes the cells are connected by Great Circles 1.

Supported tools, methods and grids:

• xESMF (https://pangeo-xesmf.readthedocs.io/en/latest/)

  • Methods:

    • Bilinear

    • Conservative

    • Conservative Normed

    • Patch

    • Nearest s2d

    • Nearest d2s

  • Grids:

    • Rectilinear

    • Curvilinear

  • Find options at xcdat.regridder.xesmf.XESMFRegridder()

• Regrid2

  • Methods:

    • Conservative

  • Grids:

    • Rectilinear

  • Find options at xcdat.regridder.regrid2.Regrid2Regridder()

Parameters

• data_var (str) – Name of the variable in the xr.Dataset to regrid.

• output_grid (xr.Dataset) – Dataset containing output grid.

• tool (str) – Name of the regridding tool.

• **options (Dict[str, Any]) – These options are passed to the tool being used for regridding. See specific regridder documentation for available options.

Returns

xr.Dataset – With the data_var variable on the grid defined in output_grid.

Raises

ValueError – If tool is not supported.

References

1

https://earthsystemmodeling.org/docs/release/ESMF_8_1_0/ESMF_refdoc/node5.html#SECTION05012900000000000000

Examples

Create destination grid:

>>> output_grid = xcdat.create_uniform_grid(-90, 90, 4.0, -180, 180, 5.0)

Regrid variable using “xesmf”:

>>> ds.regridder.horizontal("ts", output_grid, tool="xesmf", method="bilinear")

Regrid variable using “regrid2”:

>>> ds.regridder.horizontal("ts", output_grid, tool="regrid2")

Use convenience methods:

>>> ds.regridder.horizontal_xesmf("ts", output_grid, method="bilinear")

>>> ds.regridder.horizontal_regrid2("ts", output_grid)