coupling esmf atm.yaml
The coupling_esmf_<atm>.yaml (where <atm> is the model name) file specifies the ROMS Coupling ESMF/NUOPC System Import/Export Metadata Dictionary. Starting svn revision -r 1902 released on March 1, 2022, the ROMS coupling metadata is managed with a YAML file, and the regular text file coupling_esmf_<atm>.dat is deprecated. The YAML files are simple, easy to follow, elegant, portable, and expandable. ROMS can now process YAML files with its parser module, yaml_parser.F. Therefore, there is no need to use third-party YAML parsers. Basically, coupling_esmf_<atm>.yaml has the following structure:
DATA_component: data.nc
ROMS_component: &OCN ROMS
metadata:
- standard_name: sea_surface_temperature
long_name: sea surface potential temperature
short_name: SST
data_variables: [temperature, time]
source_units: C
destination_units: K
source_grid: cell_center
destination_grid: cell_center
add_offset: 273.15d0
scale: 1.0d0
debug_write: false
connected_to: *ATM
regrid_method: bilinear
extrapolate_method: nearest
- standard_name: sea_surface_temperature_data
long_name: sea surface temperature data
short_name: dSST
data_variables: [temperature, time]
source_units: C
destination_units: K
source_grid: cell_center
destination_grid: cell_center
add_offset: 273.15d0
scale: 1.0d0
debug_write: false
connected_to: *ATM
regrid_method: bilinear
extrapolate_method: nearest
The field key and value pair in the YAML blocking list is as follows:
- standard_name: CF conventions standard name for variable. A list of applicable standard_name attributes are shown below.
- long_name: The field's long descriptive name.
- short_name: The field's short name private to the NUOPC cap module
- data_variables: The DATA component NetCDF field and time variable names.
- source_units: The field's source units.
- destination_units: The field's destination units.
- source_grid: The field's source grid-cell location.
- destination_grid: The field's destination grid-cell location.
- add_offset: The value to add to the exchanged field.
- scale: The scale to use to convert data from source to destination.
- debug_write: A switch indicating whether or not to write out exchanged field, if DebugLevel>2.
- connected_to: The source component to which the field is connected.
- regrid_method: The field regridding method from source to destination:
| bilinear | bilinear interpolation |
| patch | high-order patch recovery |
| conservative1 | first-order conservative |
| conservative2 | second-order conservative |
| nearest | nearest neighbor interpolation |
- extrapolate_method: The field extrapolation method for unmapped points:
| none | no extrapolation |
| nearest | nearest source to destination |
| idavg | nearest inverse distance average |
| creep | creep fill at specified level |
| 2steps | Turuncoglu's 2 steps extrapolation |
The ESM imported fields are processed as:
- field (destination_units) = field (source_units) * scale + add_offset
YAML allows alias and anchor to avoid repetition. In YAML, single or multiple line comments start with a hash #. Also, comment after a key/value pair is allowed. All comments are skipped during processing.
