EXPERIMENTAL CF-NETCDF PROFILES FOR MARINE AND WEATHER RADAR DATA  

Data Standard 

The WMO extensions to the Climate and Forecast Conventions (CF conventions) for netCDF (WMO-CF extensions) aim to reduce the effort involved in specifying data products and ensure interoperability by providing standardized semantics and metadata.  The level of standardization provided by the WMO-CF extensions is in many cases greater than what is provided by the CF conventions to satisfy the specific WMO operational needs to support Earth System monitoring and prediction. New netCDF profiles are defined to act as templates for reporting data from different sources.  

Data Profiles 

The WMO-CF profiles implement the WMO-CF extensions by providing templates for different types of data, both observational and model-based. General regulations are provided to ensure consistency overall interoperability and consistency between different WMO-CF profiles.  The first draft version is available on the WMO SharePoint.  

Coordinates, dimensions, and groups are standardized and mandatory metadata specified in each WMO-CF profile. Two observational profiles are currently defined.  

The WMO-CF RADIAL profile should be used for the representation of weather radar and lidar data in the native instrument-centric polar coordinates. The first draft version is available on the WMO SharePoint. 

The WMO-CF MARINE TRAJECTORY should be used for the reporting of meteorological and/or oceanographic observations along one or more trajectories, including both at or near the ocean surface and at depth. The first draft version is available on the WMO SharePoint. 

The WMO-CF UAS TRAJECTORY should be used for the reporting of meteorological, atmospheric chemistry and air quality observations along one or more trajectories from a single platform. The trajectory may follow an undulating profile. The first draft is available on the WMO Sharepoint.

Data Exchange 

The data exchange of new experimental WMO-CF profiles for marine and weather radar data has been discussed by the Standing Committee for Information Management and Technology (SC-IMT). The possible option of exchanging the new data types on the GTS has been considered. However, noting the plan to retire the GTS, the difficulty of extending the GTS headers to cover the new data, the considerable effort needed to reconfigure the GTS routing for those data, and the need to test the WIS 2.0 exchange mechanisms lead the SC-IMT experts to decide that the most appropriate way to experimentally exchange the data is through a new WIS 2.0 demonstrator project.    

The following new WIS 2.0 demonstrator project has been proposed by Germany and supported by SC-IMT experts. 

Experimental WIS 2.0 data exchange for data in WMO CF-NetCDF profiles 

The project aims to experiment with international real-time exchange of data using publication/subscription (pub/sub) protocols in combination with a distributed storage of the original data along with a central, mirrored repository for easy access to the complete distributed data set. Additionally, the data will be discoverable using WIS Metadata. Thus, this project also assesses the advantages, disadvantages, and usability of WMO Core Profile 1.3 Metadata complemented by the exposure of this data to commercial search engines. The latter being seen as an input to the further development of WIS 2.0 Metadata and the topic structure for the pub/sub messaging. 

In this project, participating centers will make available their NetCDF data through the internet by using established technologies like HTTPS, FTP, or WebServices and provide discover, access, retrieve (DAR) Metadata in WMO Core Profile 1.3 to the Global Information System Center (GISC) Offenbach, either in XML-Format, through OAI, or through GISC Offenbach’s MetadataEditor. 

GISC Offenbach will use the Metadata to access and collect the available NetCDF data. Either by Centers actively pushing the data to GISC Offenbach or by GISC Offenbach harvesting the data from Centers through the Internet.  

Interested users will be able to request access and subscribe to the message brokers to receive notifications when new data will be available to be downloaded from the central repository.  

~page last updated: 18 November 2022~