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JMA Monthly and Seasonal Forecast Systems

JMA Monthly and Seasonal Forecast Systems. Yuhei Takaya ytakaya@met.kishou.go.jp Climate Prediction Division Japan Meteorological Agency. Outline. Designing Operational Forecast Systems Targets (Phenomena, Time scales, Applications) Requirements/Limitations

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JMA Monthly and Seasonal Forecast Systems

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  1. JMA Monthly and Seasonal Forecast Systems Yuhei Takaya ytakaya@met.kishou.go.jp Climate Prediction Division Japan Meteorological Agency Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  2. Outline • Designing Operational Forecast Systems • Targets(Phenomena, Time scales, Applications) • Requirements/Limitations • Current JMA Operational Systems • Monthly (uncoupled) and Seasonal (coupled) forecast systems • Practical Examples • Future Directions • Required Activities Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  3. “Designing” Operational Forecast Systems • Operational Forecast Systems are to be oriented to phenomena, user applications. ENSO Monsoon MJO 20,000 Synoptic Weather Systems Teleconnections Seasonal EPS (CGCM TL95 180 km) 2,000 TropicalCyclone Horizontal scale (km) Monthly EPS , Early Warning on Extreme Events (TL159 110 km) 200 MesoscaleWeather System Weekly /Typhoon EPS (TL319 60 km) Deterministic (JMA-GSM, TL959 20 km) 20 Atmosphericconvection JMA-NHM (5 km) 2 LFM (2km) 10 102 103 104 1d 3m 10d 1m Time scale (hours) Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  4. Current JMA Sub-seasonal to Seasonal Prediction Systems 1 month 3 months 7 months operatedmodels Early warning information on extreme events 2 weeks AGCM TL159L6050member Issued on Tuesday/Friday 1-month forecast week 1 Week 2 Week 3&4 Issued on Friday 3-month forecast CGCMJMA/MRI-CGCM AGCM: TL95L40OGCM: 0.3 -1 deg x1 deg51 member 1 month Issued every month 3 months Warm/cold season forecast 3 months (summer/winter) Issued in Feb. Sep. ENSO outlook ENSO, Indian Ocean SST Issued every month The seasonal forecast system and ENSO prediction system were integrated with an atmosphere-ocean coupled model inFeb. 2010. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  5. Requirements and Limitations • Computer Resources • Costs & Benefits • Higher Resolution • Higher Frequency • More Members Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  6. Z500&WAF200 X200 and Div Wind SST JMA Monthly EPS Precipitation, PSI200, WAF200 T850

  7. Z500&WAF200 X200 and Div Wind SST JMA Monthly EPS Precipitation, PSI200, WAF200 Precipitation, PSI200, WAF200 T850

  8. Predictability in the Midst of Chaos - Predictability at SSS Time Scale- (Shukla 1998 Science ) Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  9. JMA Monthly Forecast System Atmospheric I. C. Atmospheric perturbations Trop.&Ext.-trop. bred vector 25 members start from Wednesday. 25 members start from Thursday. 50 members in total Atmospheric General Circulation Model (JMA-GSM0803C) TL159L60 (~110km) JMA Global Data Assimilation System JMA Land Surface Analysis Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  10. Arctic Oscillation during Dec. 2009-Feb. 2010 Feb. 2010 Dec. 2009 Jan. 2010 -300 -180 -60 0 60 180 300 [m] • A negative phase of the Arctic Oscillation (AO) pattern was dominant through Winter 2009/2010.

  11. Forecast Skill of Operational JMA Monthly Forecast Anomaly Correlation Week 1 Week 2 Week 1-4 Week 3-4 Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  12. AO index in Winter 2009/2010 Index of EOF1 score (500hPa GPH, DJF mean) (1) 2009/12/10 (2) 2010/1/28 The winter 2009/2010 was the most prominent period during 1979-2010. Spatial Pattern of GPH500 EOF1 (Area weighted Covariance, 22.6 %) Computed with 1979-2005 DJF mean 500-hPa GPH. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  13. Prediction for negative AO Case Initial Date: 2009/12/10 • 1-month (4-week) mean Anomaly Correlation 0.84 Week 10.93, Week 20.77, Week 3-40.56 1-month （4-week） mean500-hPa GPH Anomaly Analysis (JRA-25) Forecast 120 90 60 30 0 -30 -60 -90 -120 [m] 0.84 Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  14. 200-hPa Westerly Jet Initial Date: 2009/12/10 200-hPa Zonal Wind Anomaly 4-Week Mean Forecasts Analysis (12/12-1/8) Forecast I.C.; 2009/12/09 Forecast I.C.:2009/12/10 14 • Strong Sub-tropical Jet • Weak Polar Front Jet [m/s] Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  15. E-vector (Hoskins et al. 1983 JAS) • Momentum Transport Diagnostics: E-vector E=(v’2-u’2, -u’v’) Cyclonic Circulation Anti-Cyclonic Circulation E Divergence Convergence Anti-Cyclonic Circulation Cyclonic Circulation Ian N. James (1994) “Introduction to Circulating Atmospheres” Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  16. Divergence of E-vector Mid-latitude 30N-40N North Atlantic 30N-40N, 90W-0 x104 [m s-2] x104 [m s-2] ●Hindcast (Initial Date: 10 Dec.) Operational Forecast (2009/12/10) ○　JRA-25/JCDASAnalysis North Pacific 30N-40N, 170E-120W x104 [m s-2]

  17. JMA Seasonal EPS Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  18. JMA Seasonal EPS • The seasonal forecast relies on the predictability that comes from the ENSO variability. • The East Asian monsoon is essentially an ocean-atmosphere-land coupled system. • Coupled models are suitable for predicting its variability at a seasonal time scale. The new JMA coupled forecast system has been up and running for the JMA ENSO prediction system since Feb. 2008, and was introduced to the JMA seasonal forecast in Feb. 2010. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  19. New JMA Seasonal Forecast System Climate Data AssimilationJRA-25/JCDAS Atmosphere-Ocean Coupled model (JMA/MRI-CGCM) Atmospheric I. C. JMA GSM （TL95L40: ~180km） Atmospheric perturbations Trop.&Ext. trop bred vector coupler (w/ flux adjustment) Ocean model (MRI.COM ) 1.0°×(0.3°-1.0°), 51 levels Ocean Data Assimilation SystemMOVE/MRI.COM-G Oceanic I. C. Atmospheric BGM + Lagged Averaging Forecast Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  20. Operational Schedule Ocean Data Assimilation Forecasts 9 members / 5 days LAF 10 days Window NINO3 SSTA Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  21. South China Flood in 2010 BBC News http://news.bbc.co.uk/2/hi/asia-pacific/4617891.stm Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  22. Precipitation Forecasts for June 2010 (I.C. : May) Beijing ECMWF Exeter Melbourne Montreal Moscow Seoul Tokyo Toulouse Washington Observation; OLR anomaly Original data are provided by NOAA. (mm/day) WMO LCwebsite http://www.wmolc.org/

  23. JMAfuture plan on the next HPC • Weekly EPS • TL479L100 (~40 km) in 2013 • Monthly EPS • TL319L100 (~60 km) in 2013 • Development of integrated Weekly EPS and Monthly EPS (Seamless system) is under discussion. • Seasonal EPS • AGCM: TL159L60 (80?) (~110 km) in 2014 • OGCM: Tripolar grid, 1deg x 0.3-0.5 deg. 53 levels. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  24. Forecast Skill wrt Lead Time • The lead time is important at a 1-month time scale. 50 ensembles ACC (Daily 500-hPa GPH) ACC (7-day mean 500-hPa GPH) 50 ensembles Scores if forecasts 3-day before used. Based on verification of real-time JMA operational forecasts in 2006. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  25. Toward “Seamless Prediction System” Week-1 Week-2 Week-3 Week-4 Weekly EPS (TL479L100) FY2013- 2-Week EPS (Early Warning) Monthly EPS (TL319L100) reforecast 2-Week EPS (TL479L100) reforecast FY ? Monthly EPS (TL319L100) reforecast FY ??? 2-Week EPS (TL479L100) Monthly EPS (TL319L100) reforecast Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  26. Required Activities for Further Improvement of SSS time scale • International research projects to investigate predictability at monthly time scale (extended TIGGE ???) • International research projects for key processes of predictability, MJO, ENSO, etc… (CLIVAR MJO WG etc. ) • Standard verification framework for operational forecasts at sub-seasonal (monthly) time scale. (under WMO, CBS? SVS?) Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  27. END Thank you for your kind attention. Hope this talk to help the coming discussion. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  28. Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  29. EOF1(AO), REOF(PNA, NAO) ScoresInitial Date: 2009/12/10 (a) EOF1 22.6 % AO, NAO, PNA Indices were well predicted. Red： Ensemble mean Blue： Analysis Grey： Each realization (c) REOF2 16.1 % (b) REOF1 16.6 %

  30. High-Frequency Wave Activity Anomaly K=½(u’2+v’2)Initial Date: 2009/12/10 K anomaly and U300 Anomalies Analysis (JRA-25 , 12/12-1/8) K anomaly and U300Anomalies Ensemble Forecast ( I.C. 12/10) Contours: 300-hPa Zonal Wind Anomaly [ms-1] Colors: High-Frequent Wave Activity Anomaly x 10-5 [m2 s-2] Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  31. Convergence of Momentum Flux ∂y (-u’v’) and U300 Initial Date: 2009/12/10 ∂y (-u’v’), U300 Anomaly Analysis (JRA-25 , 12/12-1/8) ∂y (-u’v’), U300 Anomaly Ensemble Forecast ( I.C. 12/10) Contours; Convergence of Eddy Momentum Flux by High-Frequency Variation ∂y (-u’v’) (contour interval: 2・10-4 [m s-2] ) Colors: 300-hPa Zonal Wind Anomaly[ms-1] Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  32. Ensemble Perturbations The JMA monthly forecast system produces initial perturbations using the Bred Vectors, which is specially intended to obtain large-scale growing modes in the tropics. Chikamoto et al. 2007, GRL Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  33. Tropical Bred Vector Perturbation The space-time spectrum of the 200-hPa velocity potential of the tropical bred vector averaged over the 10S–10N region. Hovmoeller diagrams of 200-hPa velocity potential averaged over the 10S–10N region for (a) the observed field, (b) the bred vector Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  34. Perturbation (500-hPa GPH Spread) • Old • Singular Vector with a simplified model (NH only) • New • Combination of BV method in the tropics and extra-tropics (NH only). OLD NEW-OLD NEW [m] Courtesy: M. Hirai@JMA Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  35. Perturbation and Spread-Skill Relationship • Perturbations in tropics contribute to increase of the spread in extra-tropics. N. H. S. H. New RMSE Old Spread Courtesy: M. Hirai@JMA Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  36. Precipitation in June 2010 Ratio to Normals Zhejiang 174 % Fuzhou 157 % Based on CLIMAT reports Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  37. Index of 1st Mode Index of the 1st Mode The 1st mode is well correlated with Wang and Fan Index (Wang and Fan ,1999). Wand and Fan Index : U850 (5-15N,90-130E) – U850 (22.5-32.5N,110-140E) Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  38. 2009/12/10 • Z500 Analysis (12/12-1/8) Forecast I.C.; 2009/12/10 Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  39. 2009/12/10 • T850 Analysis (12/12-1/8) Forecast I.C.; 2009/12/10 Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

  40. 2009/12/10 • SLP Analysis (12/12-1/8) Forecast I.C.; 2009/12/10 Workshop on “Sub-seasonal to Seasonal Prediction”, Exeter, UK, 1-3 Dec. 2010

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