Supplemental Information for obs4MIPs datasets
The datasets available through obs4MIPs in many cases are considered a current “best estimate” product produced by a team using a particular set of measurements. As a result of the obs4MIPs-CMIP6 meeting in 2015, many data providers and users made the case for obs4MIPs to enable inclusion of additional information. Examples include quantitative uncertainty information (data), codes that provide transfer functions or forward models to enable a closer comparison between models and observations, the ability to include data flags, verification data, additional technical information, etc. Note that with the new obs4MIPs data specifications it is possible to include “observational ensembles” within the dataset itself and to have them directly searchable from the ESGF. This type of additional information beyond the "best estimate" does not need to be included in the form of Supplmental Information. Finally, the inclusion of Supplemental Information for an obs4MIPs dataset is optional, and the provision for accomodating such information is considered a "feature" of the current framework of obs4MIPs. In the future, there may be better ways to accomodate such information, as one particular limitation is that the Supplemental Information is not searchable from the ESGF search engine.
Instructions for Dataset Providers: The specification of supplemental information is free form. The data provider organizes the relevant files in a directory structure of their choosing, and then archives the top level directory and associated subdirectories as a "ZIP" file. It is recommended that a README file is included in the top level directory to describe the contents and purposes of the Supplemental Information provided.
For now, publishing of supplemental information is not yet integrated with the standard ESGF publication tools. The data provider must send the ZIP file to the administrator of the data node where the dataset is stored, and the administrator needs to perform the following actions:
Instructions for Dataset Users: A user will be provided with a link to the Supplemental Information once they have found a dataset via a search. An example of the link for an example search is provided in the figure below.