Proposed naming convention for E3SM V2 and newer compsets:
Suffix = ToolAlgorithm
Tool:
map_grida_to_gridb_ToolAlgorithm.nc
Where grida and gridb are existing grid naming conventions established by the respective component.
Here we propose to standardize the suffix to denote the Tool and Algorithm used:
Tool:
esmf: Earth System Modeling Framework
nco: NCO
tr: Tempest Remap
mbtr: (for MOAB-Tempest).
...
aave: Maps which compute a common refinement (intersection) mesh and then integrate a piecewise-constant reconstruction. Conseravtive and monotone.
pros: conservative, montonone, downscaling
cons: 1st order accurate, blocky results if source grid resolution << source grid resolution
bilin: ESMF’s bilinear interpolation
pros: monotone, 2nd order accurate
mono: For spectral element (SE) grids, where the spectral element basis functions are replaced with a montone bases.
cons: non-conservative. aliasing errors if source grid resolution >> target grid resolution
patch: ESMF’s patch based algorithm (L2 projection?).
pros: accurate. is it downscaling?
cons: can have small non-monotone weights
mono: TR developed algorithms which use a spectral element with monotone basis functions. The degrees of freedom for the basis function (“np”) is usually denoted in the grid name, such as ne30np4. For FV grids, only np=1 is supported.
monoSE2FV: SE monotonic basis reconstruction integrated over FV (np=1) cells
monoSE2SE: projection between source and target grid monotonic reconstructions
monoFV2SE: does this exist?
monoFV2FV: identical to aave, recommend using aave suffix.
pros: conservative, monotone, downscaling
cons: 1st order accurate
intbilin: Integrated bilinear. For finite element grids, the shape functions are replaced by a piecewise linear shape functions which are then integrated using a common refinement mesh
pros: monotone, 2nd order, downscaling
cons: only supported for SE2FV? Does it work SE2SE?
inttrilin: Integrated linear reconstruction using triangular grids?
pros: monotone, 2nd order(?), downscaling
cons: does not exist yet!
volumetric: should we add a convention for TR’s volumetric maps?
might be useful for FV->SE maps. currently not used
highorder: Use of SE shape functions or higher order FV for reconstruction, projected onto SE shape functions, or integrated over FV cell (np=1)
The most accurate SE2SE and SE2FV maps.
Currently not recommended due to large negative weights
{algorithm}trn: For any map from grid a gridA to grid bgridB, one can compute an area weighted transpose map from grid b gridB to grad agradA. In general, the tranpose transpose map will not preserve the properties of the original map. However, the transpose of a conservative map will be conservative. The transpose of a monotone conservative map will be monotone and conservative.
...
Suffix = esmfaave, esmfbilin, ncoaave, trmono, trmonotrn, trintbilin, trhighorder, mbtrmono, ...
...
Historical usage:
_aave.nc: ESMF conservative/monotone "area averaged" maps
_bilin.nc: ESMF bilinear
_mono.nc TempestRemap conservative, monotone map
_highorder.nc TempestRemap high-order, conservative, non-monotone ( several TR options in this category )
_intbilin.nc TempestRemap integrated bilinear: monotone, non-conservative
_monotr.nc TempestRemap transpose of a mono map.
_highordertr.nc TempestRemap transpose of a highorder map. (not recommended)
...