Interoperable Access to NCAR Research Data Archive Collections

To enhance user experience and utility, the RDA now offers THREDDS Data Server (TDS) access for many highly valued gridded dataset collections (http://rda.ucar.edu/thredds).  TDS offered datasets with native formats in GRIB1 and GRIB2 are presented as aggregations,  enabling users to access an entire dataset collection that can be comprised of 1000’s of files, through a single virtual file.  Individual files can also be accessed from all GRIB1, GRIB2, and NetCDF format dataset collections found on the TDS. 

The OPeNDAP protocol (http://docs.opendap.org/index.php/QuickStart), supported by the TDS, allows compatible tools to open and access files and virtual files remotely and make the native data file format transparent to the end user.  Select tools that support OPeNDAP access include:

• The Unidata Integrated Data Viewer (IDV)
• http://www.unidata.ucar.edu/software/idv/
• Select the "Choose Data" -> "From a Catalog" option and enter http://rda.ucar.edu/thredds/catalog.xml
• The NASA panoply tool
• http://www.giss.nasa.gov/tools/panoply/ 
• Select the "Open Remote Catalog" option and enter  http://rda.ucar.edu/thredds/catalog.xml

Popular RDA datasets available through TDS include:

• NCEP Operational Final Analysis (FNL) (ds083.2)
• ECMWF Operational Model Analysis (ds113.0)
• NCEP CFS Reanalysis (ds093.1, ds094.1, ds094.2)
• NOAA/CIRES 20th Century Reanalysis (ds131.2)
• NCEP Global Ocean Data Assimilation System (ds277.6)
• NOAA CMORPH Global Precipitation Analysis (ds502.0)
• ECMWF 20th Century Reanalysis (ds626.0)
• ECMWF Interim Reanalysis (ds627.0)
• Japanese 55 year Reanalysis (ds628.0)
• Arctic System Reanalysis Project (ds631.0)
• NCAR Global CFDDA Reanalysis (ds604.0)

Click on the "Data Access" tab found at the top of a dataset homepage to find a list of data access options, including TDS access.

For a complete list of RDA datasets available through the TDS, see: http://rda.ucar.edu/thredds .  It should be noted that authentication is required using RDA user credentials to access ECMWF and Japanese datasets.