ECMWF Seattle, 6-7 June 2005 slide 1 The role of the Pacific downstream: Europe Value of Targeting Carla Cardinali Roberto Buizza Graeme Kelly Jean-Noel Thepaut

ECMWF Seattle, 6-7 June 2005 slide 2 The role of the North Pacific sea for the downstream forecast has been investigated by removing all observations over sea  1.5 month assimilation ECMWF 4D-Var T511T159L60  Compare with O-suite Targeting studies (March 2005-…) Preliminary results  Value of SVs to detect targeting areas  Ultimately, value of targeting with satellite data Outline

ECMWF Seattle, 6-7 June 2005 slide 3 Experiment Description: North Pacific OUT Synop Airep Satob DribuTemp Pilot Satellite Scatt

ECMWF Seattle, 6-7 June 2005 slide 4 The Role of the Pacific

ECMWF Seattle, 6-7 June 2005 slide 5 The Role of the Pacific

ECMWF Seattle, 6-7 June 2005 slide 6 The Role of the Pacific

ECMWF Seattle, 6-7 June 2005 slide 7 PACIFIC: NoPac forecast error – Oper forecast error at T+24 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 8 PACIFIC: NoPac forecast error – Oper forecast error at T+48 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 9 PACIFIC: NoPac forecast error – Oper forecast error at T+72 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 10 PACIFIC: NoPac forecast error – Oper forecast error at T+96 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 11 PACIFIC: NoPac forecast error – Oper forecast error at T+120 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 12 PACIFIC: NoPac forecast error – Oper forecast error at T+144 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 13 Removing all the observation over the North Pacific slightly deteriorate the day 6-7 forecast over Europe  1.5 month assimilation ECMWF 4D-Var T511T159L60  Compare with O-suite Observations over North America recover the lack over the Pacific: the impact depends on the synoptic situation  See THORPEX picture Preliminary Conclusion

ECMWF Seattle, 6-7 June 2005 slide 14

ECMWF Seattle, 6-7 June 2005 slide 15 Targeting studies The key questions addressed in this study are: Q1 - What is the value of observations taken in target areas over the ocean, and what is the ‘value’ of SVs at depicting target areas? Q2 - Is the ‘value’ of observation regional dependent? (in other words, what is the value of observations taken over the Pacific for North-America, and the value of observations taken over the Atlantic for Europe?) Q3 - What is the ‘value’ of different types of observations?  In particular, what is the scope of targeted satellite observations

ECMWF Seattle, 6-7 June 2005 slide 16 1) Experiment Description: IN SV RD V 10 ToT Energy SVs T63L40 computed every analysis cycle for 1.5 month Verification region V and area where SVs have maximum final-time total energy after 48h. IN = All Points over Sea removed but in SV and RD Target-Areas Grid Points = 120

ECMWF Seattle, 6-7 June 2005 slide 17 2) Experiment Description: OUT 10 ToT Energy SVs T63L40 computed every analysis cycle for 1.5 month OUT = All Points Removed in SV and RD Target-Areas Point left = 929

ECMWF Seattle, 6-7 June 2005 slide 18 Experiment Description: Data Coverage Pacific OUT SVIN RDIN

ECMWF Seattle, 6-7 June 2005 slide 19 Target IN

ECMWF Seattle, 6-7 June 2005 slide 20 Target OUT

ECMWF Seattle, 6-7 June 2005 slide 21 Target IN Target OUT

ECMWF Seattle, 6-7 June 2005 slide 22 PACIFIC: SVIN forecast error – RDIN forecast error at T+24 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 23 PACIFIC: SVIN forecast error – RDIN forecast error at T+48 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 24 PACIFIC: SVIN forecast error – RDIN forecast error at T+72 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 25 PACIFIC: SVIN forecast error – RDIN forecast error at T+96 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 26 PACIFIC: SVIN forecast error – RDIN forecast error at T+120 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 27 PACIFIC: SVIN forecast error – RDIN forecast error at T+144 NormDiff in RMS Averaged over 50 cases

ECMWF Seattle, 6-7 June 2005 slide 28 Key preliminary conclusions (based on ~1.5 months) Q1 - The value of observations taken in target areas over the ocean depends strongly on the underlying observations.  If the underlying system has no-observations over the ocean, than observations taken in target areas are valuable, and observations taken in SV target areas are more valuable than observations taken in Random areas  If the underlying system has observations over the ocean, than removing observations from SV or Random areas has smaller value Q2 - The value is regional dependent: the value of observations taken in the Pacific for North America is higher than the value of observations taken in the Atlantic for Europe Q3 – No conclusions yet on this point (if results are symmetrical, little scope to target with satellite observations).

ECMWF Seattle, 6-7 June 2005 slide 29 Value of Targeting the Pacific for Europe