1. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 1 A summary of OSE and OSSE activities at ECMWF. Erik Andersson, Graeme Kelly, Jean-Noël Thépaut, Gabor Radnoti, Peter Bauer and Sean Healy Acknowledgements: EUCOS, EUMETSAT, JCSDA/NCEP  Three major sets of OSEs  Investigating the complementarity between space based and terrestrial observing systems  The impact of MetOP instruments  Impact of GPS Radio Occultation data  The Joint-OSSE, followed by Conclusions

2. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 2 1: The Space-Terrestrial Study Initiated and funded by EUCOS. i.BASELINE: all satellite observations currently used in NWP (radiances, cloud-drift winds, scatt winds) + GUAN R/S + GSN surface land data + buoys (no ship data) ii.BASELINE + aircraft data iii.BASELINE + non-GUAN R/S wind profiles iv.BASELINE + non-GUAN R/S wind and temp profiles v.BASELINE + wind-profiler data vi.(iv) + aircraft data vii.BASELINE + non-GUAN R/S wind, temp and humidity profiles viii.CONTROL: the combined observing system ix.BASELINE + non-GUAN R/S temperature profiles (winter) x.BASELINE + aircraft temperature data (winter)

3. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 3 OSE assimilation system configuration  Resolutions:  Model resolution T511 (50 km), L60  Analysis at T511/T159 L60,  12-hour 4D-Var  Winter Experiments:  20041204-00 to 20050125-12 (including 10 day warm up)  Model cycle 29R1  Summer experiments:  20050715-00 to 20050915-12 (including 10 day warm up)  Model cycle 29R2  NOAA18 included (AMSU-A and MHS)

4. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 4 Winter results: Baseline – Control (Z500) Impact of terrestrial, non-climate, observations NH EUR

5. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 5 Control-Baseline (Z500) Normalised forecast error difference, Day-3

6. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 6 Z scores: Impact of R/S NH EUR 1000 hPa500 hPa

7. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 7 T scores: Impact of R/S NH EUR 850 hPa300 hPa

8. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 8 Wind scores: Impact of R/S NH EUR 850 hPa300 hPa

9. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 9 Baseline – [ Baseline + aircraft] Z500 Impact of aircraft data NH EUR

10. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 10 [Baseline + aircraft] - Baseline (Z500) Normalised forecast error difference FC+12h

11. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 11 Z scores: Impact of aircraft NH EUR 1000 hPa500 hPa

12. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 12 Wind scores: Impact of aircraft NH EUR 850 hPa300 hPa

13. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 13 [(i) + R/S T+W] – [ (i) + R/S T+W + aircraft] Z500 Impact of aircraft in the presence of R/S NH EUR

14. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 14 [(i) + R/S T+W + aircraft] – [(i) + R/S T+W] (Z500) Z500 Impact of aircraft in the presence of R/S

15. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 15 [(i) + R/S T+W] – [ (i) + R/S T+W + aircraft] W300 Impact of aircraft in the presence of R/S NH EUR

16. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 16 [(i) + aircraft] – [ (i) + R/S T+W + aircraft] W300 Impact of R/S in the presence of aircraft NH EUR

17. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 17 [(i) + R/S T+W] – [ (i) + R/S T+W+Q] RH700 Impact of R/S humidity NH EUR

18. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 18 EUCOS Space-Terrestrial, Conclusions (1)  Even in presence of satellite observations, degrading the current terrestrial Observing System has a significant negative impact on the forecast skill.  Starting from the degraded baseline (GUAN+GSN+…):  Additional R/S (T+Wind) and aircraft (T+Wind) contribute more or less equally to the Observing System (slight advantage for R/S)  These two Observing Systems are complementary  Aircraft add forecast skill to R/S  R/S add forecast skill to Aircraft

19. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 19 EUCOS Space-Terrestrial, Conclusions (2)  R/S impact:  R/S winds contribute little on their own  Radiosonde T contribute marginally more  This is the combination of wind/T which really provides the impact of the RS on the forecast skill  Aircraft impact:  The results are consistent with that of R/S. Aircraft-T alone bring relatively little. Combination of T/Wind makes a big impact

20. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 20 EUCOS Space-Terrestrial, Conclusions (3)  Humidity from R/S add very little in terms of scores  Noticeable but small impact on relative humidity scores up to day 3  Impact of wind profilers:  Winter impact:  The short range forecasts are improved by the US and japanese profilers  The signal blurs away after day 4-5 and large scale interactions appear  European profilers do not bring much  In summer, the impact is smaller than during the winter period (in absolute but also relative terms)

21. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 21 2a: Assessment of the space component of the GOS Initiated and funded by EUMETSAT Winter period: 20041204-20050125, Summer period: 20050715-20050915 (cycle 29r1)  BASELINE all conventional observations used in NWP (radiosonde + aircraft + profiler network + surface land data + buoy observations + ship data)  REFERENCE= BASELINE + AMVs from GEO+MODIS  REFERENCE + HIRS radiances  REFERENCE + AMSUA radiances  REFERENCE + AMSUB radiances  REFERENCE + SSMI radiances  REFERENCE + GEO Clear Sky Radiances (CSRs)  REFERENCE + AIRS radiances  REFERENCE + SCAT winds  BASELINE + GEO AMVs (no MODIS)

22. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 22 2b: Assessment of the space component of the GOS Initiated and funded by EUMETSAT Winter period: 20061205-20070214 (31r1), Summer period: 20060601-20060815 (31r2) i.BASELINE all conventional observations used in NWP (radiosonde + aircraft + profiler network + surface land data + buoy observations + ship data) ii.REFERENCE= BASELINE + AMSUA Noaa 16 iii.REFERENCE + AMVs from GEO+MODIS iv.REFERENCE + AMSUA radiances v.REFERENCE + AMSUB radiances vi.REFERENCE + GEO Clear Sky Radiances (CSRs) vii.REFERENCE + AIRS radiances viii.REFERENCE + SCAT winds ix.CONTROL full operational system (all above observations)

23. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 23 Average Z 500 anomaly correlation scores The AMV reference and the AMSU-A reference All AMVs ref One AMSU_A ref One AMSUA_ ref S.Hem N.Hem S.Hem

24. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 24 Z500 impacts, S.Hem (REFERENCE_AMV) HIRS, AMSU-A, AIRS AMSU-B, SSMI, GEO_CSR Scat, GEO_AMV, GEO_CSR

25. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 25 Relative Humidity 850hPa impacts, S.Hem (REFERENCE_AMV) HIRS, AMSU-A, AIRS AMSU-B, SSMI, GEO_CSR Scat, GEO_AMV, GEO_CSR

26. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 26 Vector wind 200 hPa impacts, S.Hem (REFERENCE_AMV) HIRS, AMSU-A, AIRS AMSU-B, SSMI, GEO_CSR Scat, GEO_AMV, GEO_CSR

27. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 27 Impact of removing MODIS from the REFERENCE_AMV

28. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 28 500z amsu_a reference

29. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 29 Tropical Humidity amsu_a reference

30. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 30 Tropical Vector wind amsu_a reference

31. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 31 Space component, Summary  Very encouraging that all the space base sensors contribute in a positive way to the overall performance of the ECMWF forecast system. Sensors like AMSU-A, AIRS and HIRS are the most important.  The humidity analysis requires AMSUB (also MHS), GEO CSRs and SSMI.  Amongst the wind data, SCAT has a clear positive impact on the surface wind in the Southern Hemisphere, and a clear beneficial impact of AMVs and MODIS winds has been demonstrated.

32. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 32 3: OSEs for the evaluation of degraded EPS/Post- EPS instrument scenarios (EUMETSAT) The objective is to assess the detrimental impact of potential loss of the main EUMETSAT Polar System (EPS) instruments on global NWP.  REFERENCE: All conventional data + 2*AMSU-A, 2* DMSP, AIRS and IASI, ASCAT and QuikSCAT.  REFERENCE – HIRS  REFERENCE – AMSU  REFERENCE – MHS  REFERENCE – SOUNDERS  REFERENCE – IASI  REFERENCE – ASCAT  REFERENCE – METOP

33. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 33 METOP forecast impact 500 hPa geopotential height RMS error difference when METOP data withdrawn [%/100] T+12 hours T+24 hours

34. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 34 Preliminary results on Metop (ongoing study)  The fit to temperature-sounding instruments (e.g. NOAA- 18 AMSU-A) is improved when Metop instruments are present.  The fit to moisture-sounding instruments (e.g. AIRS, MHS, GOES) is improved when Metop MHS, all Metop sounders or IASI are present  The presence of ASCAT data slightly improves the fit to QuikSCAT wind data, and products from Envisat and Jason altimeters  The synergy of Metop instruments produces a much stronger impact than its individual instruments

35. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 35 GPS radio-occultation. Current 6-hour data coverage.

36. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 36 December 2006: Assimilation of RO data at ECMWF All 6 satellites Wave-like bias disappeared

37. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 37 GPSRO impact on Southern hemisphere geopotential height forecasts 6 COSMICs+CHAMP+GRACE-A (setting only, z > 5 km) – no GPSRO 1100 observations/day, 66 cases, winter 2006/2007, own analyses 1000 hPa500 hPa 200 hPa100 hPa (Sean Healy)

38. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 38 GPSRO impact on Southern hemisphere geopotential height forecasts 6 COSMICs+CHAMP+GRACE-A (setting+rising, z > 5 km) – no GPSRO 1600 observations/day, 66 cases, winter 2006/2007, own analyses 1000 hPa500 hPa 200 hPa100 hPa (Sean Healy)

39. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 39 MetOP GRAS: NH height scores

40. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 40 Metop GRAS: SH height scores

41. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 41 Advanced infrared sounders: AIRS and IASI AIRS  Operational at ECMWF since October 2003.  324 channels received in NRT.  One FOV in nine used.  Up to 155 channels may be assimilated (CO 2 and H 2 O bands). IASI  Operational at ECMWF since June 2007.  8461 channels received in NRT.  All FOVS received; only 1-in-4 used.  366 Channels routinely monitored.  Up to 168 channels may be assimilated (CO 2 band only).

42. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 42 IASI better IASI worse IASI better IASI worse SH NH 500 hPa geopotential anomaly correlation (56 cases, spring 2007, normalized RMSE difference, own analysis) Mean error differenceuncertainty IASI forecast impact

43. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 43 Choosing 10 IASI Water Vapour Channels

44. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 44 Fit to other observations Increasing assumed IASI H 2 O channels’ error Normalized Analysis Departure Std. Dev. Best value at 1.5K ∞

45. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 45 The Joint OSSE Nature Run  Collaboration with NCEP (Michiko Masutani) to plan, produce, deliver and evaluate the NR. Consultation with the Joint-OSSE group in the US, EUCOS, ESA, EUMETSAT and ECMWF  T511 NR: 13 months T511/L91.  Data set size ~2.5 Tbyte. Shipping to the US on 4 disks  Yearly, quarterly and monthly comparison with climate and observations = 831 plots. Posted on NCEP web site  Extensive evaluation of the NR by US partners  T799 NR: Two 6-week periods have been run at T799/L91 with hourly post processing: TC-season, Convective season

46. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 46 T511 Nature Run, 12-month total precipitation

47. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 47 Nature Run, 12-month total cloud cover

48. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 48 Nature Run, 12-month total cloud cover, difference with respect to MODIS observations

49. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 49 Comparison of extra-tropical cyclones in the NR against cyclones in the NCEP analyses for 5 recent years (green bars), showing central pressure (hPa, left) and life span (days, right panel). Courtesy Joe Terry (NASA).

50. ECMWF WMO Workshop19-21 May 2008: ECMWF OSEs Slide 50 OSEs and OSSE activities at ECMWF Conclusions  Space-terrestrial study (EUCOS) completed  Assessment of space-component of the GOS (EUMETSAT) completed  Assessment of Metop impact (EUMETSAT) is ongoing  Comprehensive reports are available  ECMWF Newsletter No 113, page 16-28 (Kelly and Thépaut)  Metop-IASI and GPS-RO constitute significant new additions to the GOS  Joint-OSSE framework being developed, attracting a lot of interest, generating wide-spread collaboration