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GODAE Quality Control Pilot Project. An initiative aimed at improving the effectiveness of automated quality control procedures for GODAE prototype systems History Apr 2001 - need for systematic approach to ocean data quality control in support of GODAE recognized at US GODAE Workshop
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GODAE Quality Control Pilot Project An initiative aimed at improving the effectiveness of automated quality control procedures for GODAE prototype systems History Apr 2001 - need for systematic approach to ocean data quality control in support of GODAE recognized at US GODAE Workshop Jul 2001- need reiterated at GODAE IPRC workshop at U. Hawaii Dec 2001- model and data assimilation quality control monitoring and evaluation project formulated at the IGST VI meeting May 2002 - became integral part of the GODAE implementation plan Jun 2002 - QC workshop held in conjunction with GODAE symposium in Biarritz Oct 2003 - initiate QC methods and outcomes intercomparison project Biarritz Workshop Report: www.bom.gov.au/bmrc/ocean/GODAE/frames.html
Ocean Data Quality Control • Data quality control is a fundamental component of any ocean data assimilation system • accepting erroneous data can cause incorrect analysis • rejecting extreme data can miss important events and anomalous features • Quality control involves checking data against a pre-established set of standards • requires clearly documented procedures • depends on the reliability of the standards and the choice(s) made for measuring goodness of fit • assumptions concerning the distribution and coherences of observation errors relative to the standards need to be routinely examined
Goals GODAE Quality Control Pilot Project • Document ocean data quality control procedures in use today • real-time or delayed-mode • fully automated or man-machine mix of operations • any data type that directly impacts ocean state estimation process (in situ and remotely sensed) • Initiate intercomparison projects among groups performing QC • routine sharing of QC results (real-time and delayed mode) • define QC outcomes (metadata) that can be shared among data users • describe QC test procedures needed in the future (e.g. specific instrumentation error checks) • Develop partnerships with data providers • feedback on model-data differences • data acceptance, data rejection rates • identification of systematic problems in observing systems
Participants GODAE Quality Control Pilot Project • US Navy (NRL - FNMOC, NAVOCEANO) - J. Cummings • real-time, fully automated • all operational data sources (profile and in situ off GTS, satellite data from NAVOCEANO) • Met Office (FOAM, ENACT) - M. Huddleston, B. Ingleby • real-time, delayed mode, automated and manual (visual inspection) • profile, in situ data (GTS) • MEDS (GTSPP) - B. Keeley • real-time, delayed mode, automated and manual (visual inspection) • profile, in situ data off GTS • Coriolis Center (SOAP/MERCATOR) - T. Carval • real-time, delayed mode, automated and manual (visual inspection) • profile, in situ data (GTS)
Status GODAE Quality Control Pilot Project • QC Pilot Project web page created on GODAE server • QC system documentation available - MEDS, FOAM/ENACT, Coriolis, NRL • QC data on GODAE server • NRL QC data files updated daily (all sources, in situ and satellite) • MEDS GTSPP files updated every 3 days • links to Coriolis Center Mercator/SOAP data • code to read different formats and produce common ASCII text format for intercomparison of QC outcomes under development • formed liaison with CLIVAR GSOP/DPM (SIO, Feb 2004) • access to additional scientific QC data for intercomparison • access to delayed mode/scientific QC procedures: can delayed mode QC procedures be automated and run in real-time?
Plans GODAE Quality Control Pilot Project • Focus on Argo data for initial intercomparison study • existing, well defined data management strategy • real-time and delayed mode QC in place with feedback mechanisms • observations are readily available and widely used • Reanalysis effort using expertly QC’d Indian Ocean data from CSIRO • compare with Enact dataset, NRL R/T system, World Ocean Database, others? • examine regional and/or temporal variability in patterns of rejection • detailed cross-evaluation of profiles rejected by one system and accepted by another (knowing “truth” from expert) • test down-stream effects of QC decisions • what is added value of a model to the process • what is effect of differential profile acceptance/rejection on derived ocean products • define factors that influence both R/T and scientific QC acceptance and rejection rates