Gridspecs (for precomputed weights)

A gridspec describes spatial grids in the form a dict.

Warning

The gridspec format is not finalised yet and may change in future releases. Subarea specification is not yet supported.

The gridspecs supported when regridding with the precomputed backend are summarised below:

Global octahedral reduced Gaussian grid

The grid format is:

[Oo]XXX

where XXX is the number of latitude lines between the pole and equator. For details about this grid, see here.

Example:

{"grid": "O320"}
{"grid": "o320"}

Global (non-octahedral) reduced Gaussian grid

The grid format is:

[Nn]XXX

where XXX is the number of latitude lines between the pole and equator. For details about this grid, see here.

Example:

{"grid": "N320"}
{"grid": "n320"}

Global regular latitude-longitude grid

The grid format is:

[DLON, DLAT]

where DLON and DLAT are the increments in degrees in longitudes and latitudes, respectively. This grid definition uses the default scanning mode used at ECMWF: values start at North-West and follow in consecutive rows from West to East, where West is always the 0° meridian.

Example:

{"grid": [1, 1]}

HEALPix nested grid

The grid format is:

[Hh]XXX

The order must be set to "nested". For details about this grid, see here.

Example:

{"grid": "H512", "order": "nested"}
{"grid": "h512", "order": "nested"}

HEALPix ring grid

The grid format is:

[Hh]XXX

The order can be omitted or set to "ring". For details about this grid, see here.

Example:

{"grid": "H512", "order": "ring"}
{"grid": "H512"}
{"grid": "h512"}

ORCA grid

The grid format is:

eORCAXXX_subtype

The subtype must be “T”, “U”, “V” or “W”.

Example:

{"grid": "eORCA025_T"}