HR: 14:55h
AN: SF33B-06    [Abstracts]
TI: The NOAA Operational Model Archive and Distribution System: A Status Report
AU: * Rutledge, G
EM: Glenn.Rutledge@noaa.gov
AF: NOAA National Climatic Data Center, 151 Patton Ave, Asheville, NC 28801 United States
AB: The NOAA Operational Model Archive and Distribution System (NOMADS) at the National Climatic Data Center (NCDC) have been serving model and other data since August 2003. During the past year, approximately 13,000 unique users obtained up to one-half million individual model data elements per month. This represents the first US National archive for weather models and data. While the NOMADS services many Gridded Analysis and Display System (GrADS) users, other users are obtaining these data in the format neutral data transport mechanism known as the Data Access Protocol (DAP), being developed by the non-profit organization OPeNDAP (formally the Distributed Oceanographic Data System, or DODS). Traditional Web and ftp services are also available however nearly three quarters of the users are using the sub-setting and host side data manipulation capabilities inherent in the DAP distributed data paradigm. While the current success of NOMADS, at both NCDC and at NCEP can be attributed to the sub-setting capabilities and the relatively advanced level of it's current users, some of the known limitations in the NOMADS distributed data services model have yet to be seen. Of concern at NCDC is unknown server loading for multiple high volume requests for the soon to be available NCEP North American regional Reanalysis (NARR). It is expected that this 25 year, 12km regional reanalysis, The NCDC NOMADS is NCEP's primary distribution point for this new data, and NARR will have many uses, crossing several science disciplines. Many users will continue to opt to subset via the NOMADS interfaces, however many institutions require the entire period of record, which is approximately 5 Terabytes in volume. System architecture efforts are underway to expand NCDC NOMADS serving capabilities to accommodate the NARR. It is hopped that NOMADS can provide input to the DAP developers regarding the level of robustness in an operational setting. The NOMADS system is one of the first operational systems of its kind and filled a gap in the geosciences community for retrospective model data access. However users continue to request all the data, even though a subset is actually required. It is clear that many users are becoming more adept at distributed data access tools and the philosophy surrounding it, due in part to the large number of data providers adopting distributed data services and the DAP and the number of desktop clients now supporting the DAP libraries. However, as technology changes and other advances in distributed computing emerge, the challenge facing the Gesoscience community will be to forge agreements for interoperability using standards based metadata and transport mechanisms.
UR: http://www.ncdc.noaa.gov/oa/model/model-resources.html
DE: 3337 Numerical modeling and data assimilation
DE: 3399 General or miscellaneous
SC: Special Focus: Advances in Data Acquisition, Management, Analysis and Display [SF]
MN: 2004 AGU Fall Meeting