Grids
One page per grid: index sets, geometry, stencils, and the complete boundary-condition-carrying rewrite rules published for it.
Everything specific to a grid lives under grids/<grid>/ — grid.esm (index sets + geometry, metaparameterized), stencils/ (interior operators), rules/ (stencil + boundary conditions = the complete rewrite rule). The same scheme takes a different form on different grids; each page below documents one grid and every rule available on it.
- cartesian_nonuniform_1d
Non-uniform 1-D Cartesian grid with consumer-supplied edge geometry: N cell-centered points whose spacing varies along x.
- cartesian_uniform_1d
Uniform 1-D Cartesian grid with consumer-supplied extent: N cell-centered points, cell centers x_i = x0 + (i - 1/2) dx.
- cartesian_uniform_2d
Uniform 2-D Cartesian grid with consumer-supplied extent: NX by NY cell-centered points, cell centers (x_i, y_j) = (x0 + (i - 1/2) dx, y0 + (j - 1/2) dy).
- column_nonuniform_1d
Single atmospheric (or oceanic/soil) COLUMN with consumer-supplied edge geometry: NLEV cell-centered layers stacked along the vertical index `lev`, plus the NLEV+1 layer interfaces `lev_nodes`.
- duo
Generic gnomonic cubed-sphere grid with the duo-grid halo system of Chen (2021): six N-by-N tiles interlocked in the 'staircase' arrangement, 6 N^2 cells, unstaggered (A-grid) so every prognostic variable is collocated at cell centres.
- latlon
Uniform longitude-latitude grid with consumer-supplied extent (global or regional).
- latlon3d
Three-dimensional longitude-latitude-level grid: the 2-D grids/latlon horizontal mesh extended with a vertical `lev` axis, for 3-D tracer transport on a lat-lon model such as GEOS-Chem Classic.
- mpas
MPAS unstructured spherical centroidal-Voronoi (icosahedral) C-grid on the unit sphere: NCELLS Voronoi cells, NEDGES edges, NVERTICES triangle vertices, with cell valence bounded by MAXEDGES (on a closed sphere the Euler relations give NEDGES = 3*(NCELLS - 2) and NVERTICES = 2*(NCELLS - 2), but the three counts stay independent metaparameters so planar or open meshes can reuse the file).