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This is still a work in progress...

Text in black can be considered well-established, but text in orange is still under discussion

File formatting

The output files are written through the NetCDF API
The NETCDF4 _CLASSIC model will be adopted
Recommended compression level deflate=6
Shuffling=True
Fletcher32=True is strongly recommended

File Structure

Each netCDF4 file contains a single output variable (along with coordinate/grid variables, attributes and other metadata) from a single model and a single simulation (i.e., from a single ensemble member and a single start date)
There is flexibility in specifying how many time slices (samples) are stored in a single file. A single file can contain all the time-samples for a given variable and climate experiment, or the samples can be distributed in a sequence of files.
Recommended maximum file size of 4GB
A file containing a hash created with sha256sum should be created for each file
sha256sum filename.nc > filename.sha256

File Naming

NEW PROPOSAL (20170419):

<institute>_<model_id tag>_<modeling realm>_<frequency>_<level>_<start date identifier>_<data year><data month><data day><data hour>[-<data year><data month><data day><data hour>]_<variable name>_<ensemble member>.nc

OLD PROPOSAL:

examples:

egrr_enfh_atmos_day_sfc_201601A_19950417-19950418_ta_r3.nc
egrr_enfh_atmos_month_plev_201601A_199504-199505_ta_r3.nc

"201601A" is a placeholder while a form for representing the model version, production year and startdate is determined:
egrr_enfh_atmos_month_plev_P2016_M1A_S19950401_199504-199505_ta_r3.nc
P=production year M=model version S=startdate

e.g. could the filename (alternatively) be something like: e
grr_enfh_atmos_month_plev_S19950401_199504-199505_ta_r3p20160101m411.nc

Metadata

The metadata is constrained by the CF convention (NetCDF Climate and Forecast (CF) Metadata Convention)
This is also based on information from the SPECS_standard_output.pdf document, the CMIP5 tables and the Attribute Convention for Data Discovery.
- Attributes currently are a significantly reduced subset of the SPECS/CMIP5 requirements with minor adaptations