To facilitate the exchange of OSSE data sets between research participants, the Goddard NCCS, working in close cooperation with SIVO, is establishing an OSSE data portal. This will be an augmentation of the existing NCCS data portal currently utilized for other Goddard projects specifically to accommodate the upload and download of OSSE data, some of which will be restricted. The need for such a portal arose from the limitation of existing servers and support services to handle the enormous amount of data, the restrictive aspect of the data, and the bi-directional transfer of the data. In addition, future exchange of information may require even more sophisticated support services that only the NCCS data portal could provide. Without this portal, collaboration in future OSSE research at Goddard and perhaps elsewhere in the international OSSE community would be considerably more difficult.

The portal will exist outside the Goddard firewall and therefore will not require any elaborate protocols for access. A simple username and password provided to each user along with an agreement not to share certain pre-specified data is all that is needed. Internally, any requests for placing data on the portal and the actually copying of data to the portal will be managed by the SIVO OSSE group. The size of the OSSE portal will be initially set at 3TB. At some point when this becomes insufficient, data files existing on the portal will be swapped with files of more immediate need as per either outside or internal requests; acquisition of additional disk space is also an option.

The OSSE data that is anticipated to move through the portal include:

• T511 nature run
  - Full model resolution fields
  - Reduced resolution pressure level fields
  - Isentropic fields
• T799 nature run
  - Similar to T511 nature run items
• Simulated observations
  - Conventional
  - Satellite radiances (TOVS, AIRS, etc.)
  - GOES cloud motion vectors
  - Lidar
  - Scatterometer
• Experimental results (Gridded)
  - Analysis fields from DAS
  - Forecast fields
  - Diagnostic results
• Other
  - Modified/enhanced fields such as clouds from T511/T799 nature runs
  - Real observations as needed

Status of OSSE Data Portal

The Goddard NCCS OSSE portal has been established, however full access from outside Goddard is not yet available. Due to restrictions on the dissemination of the ECMWF nature runs, a username and password will be required for access to the OSSE portal.

What is currently in place?

• 3TB of disk space.
• Read/write access to this disk space by Goddard NCCS personnel and the SIVO OSSE portal data manager.
• A web service allowing easy browsing and transfer of the contents via Internet.
• All one degree version data from the T511 nature run (surface and pressure level).
• All full resolution surface and isentropic data and most of the full resolution model level data (approximately the first 11 months).
• Approximately 250GB of free space for other files, such as observations, software, etc.
• The ability of the portal data manager to swap out files as needed at the request of outside users. Space restrictions may require this in the future.
• Access speeds to pull data from the portal have been clocked at 10Mbits per second.

What is planned?

• Read access by outside Goddard users who have permission from ECMWF to receive the nature run.
• Write access for all users so that two-way transfer of any OSSE- related files will be possible.
• Access to the T799 nature run when it becomes available.
• A Grads/DODS server is being considered
• Additional disk space may be provided