OSTIA : Transition to an Operational System

1. OSTIA : Transition to an Operational System John Stark, Craig Donlon. GlobColour / Medspiration Workshop, 4-6 Dec. 2006

2. Overview OSTIA : Operational Sea surface Temperature and sea Ice Analysis • Description of the OSTIA system. • Data processing • Analysis & bias correction. • Products. • From innovation to operation. • The transition process. • Operational status. • Products and verification.

3. Operational SST & Sea Ice Analysis • Daily 1/20° (~5.6km) global SST analysis using optimal interpolation. • Blend of data sources, using satellite (microwave & IR) and in situ data. • Now running daily in an operational suite starting at 0600 UTC. • Persistence based; No explicit model. • Uses sea ice analysis performed by EUMETSAT OSI-SAF (met.no / DMI). Sample analysis for 24 Jan 2006

4. Basic Architecture Data Sources Quality Control -Background check -Diurnal warming flagging Anomaly Persistence Forecast With relaxation to climatology Satellite Bias Estimation -Find match-ups -O.I. estimate. O.I. Analysis -Using 2 background error scales -Spatially varying backgrd. errors Daily SST

5. OSTIA : Source Data

6. Bias correction : The Importance of AATSR AMSR-E Observations for 14 Dec. ‘05 Reference observations (With AATSR) Reference observations (No AATSR)

7. Bias correction : The Importance of AATSR More match ups especially in data-sparse areas Large impact from additional match ups Match ups (<25km) Analysed AMSRE bias for 14 Dec.

8. AATSR bias correction & SSES. • AATSR bias specification has a significant impact on OSTIA. • A short reanalysis showed that the AATSR SSES bias was too large. • We appreciate the rapid response of Medspiration in changing the SSES bias (from 0.33 to 0.19). • But the change was not directly communicated to us… Difference (K) between operational OSTIA and a run with AATSR bias=0.0

9. Products • Browsable SSTs and Anomalies http://ghrsst-pp.metoffice.com/data/private/sst_monitor/ http://lovejoy.nerc-essc.ac.uk:8080/ncWMS/godiva2.html

10. Products, Users and Applications • Seasonal forecasting. • E.g. Winter forecast. • Climate monitoring, inc. ENSO. • Aviation Forecasting Centre • Research • E.g. High resolution SSTs for monsoon modelling (U. Reading) • Intercomparison / validation • NASA Short-term Prediction Research and Transition Centre (SPoRT) • Data supplied in GHRSST L4 format via website : • http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html • ftp details available on request. • NWP boundary condition. • Beginning extensive trials with NWP suite. • Will participate in GHRSST GEO Action : DA-06-03 to use ensemble techniques to improve SST uncertainty estimation. NASA Sport Web Page.

11. Innovation to Operation… • The transition to an operational system has many advantages • Operators monitor the system 7 days a week. • Robust system. • Machine resources are dedicated to the system (06000640 UTC). • All procedures are clearly defined. • Allows rapid response to incidents. • Forces ‘Good Practise’, such as version control etc. • But places requirements on the whole system: • All changes must be justified and documented. • Any changes to data supply should be made a long time in advance if possible. • Need stability in data delivery. • Not all operators have in-depth knowledge of the system. • There should be simple ‘how-to’ procedures for likely failure modes. • Processing MUST finish within the allocated time period.

12. Sea Ice Reanalysis Near 90 GHz Bootstrap NASA/Team • Currently performing a sea ice reanalysis for the SSMI era (1987-2005) • Hope to extend to SMMR (1979-1987). • Using processing system developed for the EUMETSAT OSI-SAF. • Aim to quantify errors to provide a climate-quality product. Courtesy of Søren Andersen

13. SST Reanalysis Plans • SST Reanalysis back to 1981 using available satellite data and in situ obs. • Aim to produce a homogenous 25+ year SST data set for seasonal forecasting by end of 2008. • Initially focus on Pathfinder (AVHRR) and (A)ATSR, by end of 2007. • Intercomparison with other GHRSST (re-)analyses. • Requires access to (A)ATSR data for effective bias correction. • Ideally L2P format. • Open to collaboration • Error covariances, ensemble techniques, D.V. (ocean colour?), aerosols (ocean colour)…

14. Priorities / Requests. • Please maintain a continuous L2P data stream • Currently plan OSTIA to be the primary GMES Marine Core Services L4 SST output. (Operational backup from France). • Recommend the L2P format as it facilitates the transition to new data sources e.g. MetOp. • Maintain AATSR  Sentinel III • The presence of a high quality satellite SST data source is crucial to our bias correction strategy. • Bias correction scheme will be compromised without AATSR. • Ensure (A)ATSR is available (in L2P) for reanalysis efforts. • Please communicate changes to the system to users in an operational manner (timely and accurate).

15. Conclusions • We are treating Medspiration as an operational service • Using the service on a daily basis. • Have been some hiccups that should be ironed out . • Short interruptions to the service have occurred. • OSTIA’s strength is that is uses many complementary data sources. • Not totally reliant on a single data source – but accuracy significantly enhanced by AATSR. • Sea ice reanalysis will be available for use.