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Update, operational weather forecast

Update, operational weather forecast. Lidia Cucurull GPS RO Program Scientist NOAA. COSMIC IAWG, 18 January 2010. Assimilation code updates. More accurate forward operator for refractivity Three term expression Analysis of different sets of refractive indexes

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Update, operational weather forecast

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  1. Update, operational weather forecast Lidia Cucurull GPS RO Program Scientist NOAA COSMIC IAWG, 18 January 2010

  2. Assimilation code updates • More accurate forward operator for refractivity • Three term expression • Analysis of different sets of refractive indexes • Update of the quality control procedures • More observations (in particular in tropical latitudes) • Optimal observation error characterization • Smoother normalized differences • No empirical tuning • Changes resulted in an improvement in model skill in SH (mass fields) and reduction of the low- and high-level tropical wind errors. • These changes were implemented operationally in December 2009 • Detailed description of the changes and results can be found in Cucurull 2010 (WAF, in press).

  3. Recent impact with COSMIC • AC scores (the higher the better) as a function of the forecast day for the 500 mb gph in Southern Hemisphere • 40-day experiments: • expx (NO COSMIC) • cnt (old RO assimilation code - with COSMIC) • exp (updated RO assimilation code - with COSMIC) COSMIC provides 8 hours of gain in model forecast skill starting at day 4 !!!

  4. Additional sensors MetOp/GRAS: • Data started being archived at NCEP in July 2008. • A bug in the encoding of the BUFR files (this takes place at DMI) was identified and it was fixed in the operational data processing on 11 Nov 2008. • Data started being monitored in GDAS in March 2009 (after Feb 2009 code update & transition from DDS to TOC/TNC). GRACE-A: • Data started being archived in May 2008 and monitored in GDAS in March 2009 (after Feb 2009 code update & transition from DDS to TOC/TNC). • The bug in MetOp/GRAS BUFR files also affected GRACE-A - GFZ (processing center for GRACE-A) fixed the bug in the operational data processing on 14 Nov 2008. • The QC for MetOp/GRAS and GRACE-A has been tightened below 10 km in the GSI, as compared to COSMIC. • Impact experiments with MetOp/GRAS and GRACE-A showed encouraging results • A real time testing parallel with MetOp/GRAS and GRACE-A is underway (final step before operational assimilation)

  5. Other accomplished milestones • UCAR upgraded the processing of the COSMIC observations. The changes modified the statistics of the data (bias and standard deviation in stratosphere). A rigorous testing and evaluation of the impact of the new data was conducted. The new processing became operational in October 2009. • Collaborative project with CWB (Taiwan) enable testing the use of COSMIC into the NCEP’s regional data assimilation system (NAM). • Preliminary evaluation of SAC-C (Argentinean mission) sample data for possible transition to real-time -currently delivered in non-real time- and TerraSAR-X (German mission) -data in real-time but not distributed to the external community yet. • Proposal submitted to evaluate ROSA (Italian RO receiver) on Oceansat-2 has been approved • Collaboration project with Spain IEEC for launch of a COSMIC-type receiver for RO and modified antennas (multi polarized) to detect heavy precipitation (recently funded by Spanish Government).

  6. Outlook • Monitor current GPS RO observations (maintain operational effectiveness) • Evaluate future RO sensors (as early as possible) to enable operational assimilation of the new data as soon as possible. • Future development work with GPS RO will focus on improving the forward operator (and consequently QC and error characteristics) • Lower troposphere • Sensitivity to compressibility factors, carbon dioxide and liquid water • Bending angle – caring for the interaction with radiance data (bias correction) • Participate in International RO Working Group (IROWG), recently formed by CGMS • Support the design & requirements for a COSMIC follow-on mission

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