1. New Coupled Forecast System at the Japan Meteorological Agency Yuhei Takaya 1 (ytakaya@met.kishou.go.jp), Tamaki Yasuda 2, Satoshi Matsumoto 2, Tosiyuki Nakaegawa 2, Hirotaka Kamahori 1 and Tomoaki Ose 2 1. Climate Prediction Division, Japan Meteorological Agency 2. Meteorological Research Institute, Japan Meteorological Agency NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida

2. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute 2 History of ENSO Monitoring and Forecast Service at JMA 1992 1996 1999 2003 2008 2010 The Second Version of JMA’s CGCM (JMA-CGCM02) Launch of ENSO Monitoring Service Start-up of Ocean Monitoring with the Operational Ocean Data Assimilation System (ODAS) Start-up of ENSO Forecast Service with the CGCM (JMA-CGCM) The New Version of JMA’s Coupled Forecast System ( MOVE-G/MRI.COM, JMA/MRI-CGCM) Seasonal Forecast with a CGCM

3. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute 3 Table of Contents Introduction of a new JMA’s coupled forecast system for ENSO forecast –New ocean assimilation system (MOVE-G/MRI.COM) –New atmosphere-ocean coupled model (JMA/MRI-CGCM) Forecast skill of ENSO and Asian summer monsoon Summary

4. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute JMA Forecast System for ENSO Prediction Coupled model (JMA/MRI-CGCM) Atmospheric model (JMA/MRI Unified AGCM) Ocean model (MRI.COM) Coupler Ocean Data Assimilation System (MOVE/MRI.COM-G) Atmospheric Analysis (JRA-25, JCDAS)

5. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Ocean Data Assimilation System (MOVE-G/MRI.COM) MOVE (Multivariate Ocean Variational Estimation) System Usui et al. (2006) Ocean Model : MRI Community Ocean Model (MRI.COM) 3D-VAR(T,S) Observation Data: T, S on GTS, SST (COBE-SST, Ishii et al. 2005), SSH (TOPEX/POSEIDON, JASON-1, ERS-1,2, ENVISAT) Vertical Coupled Temperature-Salinity EOF modes Fujii and Kamachi(2003) Incremental Analysis Update (IAU)

6. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Improvement of the thermocline variability shade: dT/dz lines: isotherms of 20°C The MOVE system represents the more realistic interannual variability of thermocline. TAO OBS. MOVE-G CURRENT

7. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Comparison of Temperature Climatology The temperature climatology of MOVE system is relatively close to the climatology of WOA01. Forget, Heimbach, and Menemenlis (2006) CLIVAR/GODAE Meeting on Ocean Synthesis Evaluation

8. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Comparison of Salinity Climatology Forget, Heimbach, and Menemenlis (2006) CLIVAR/GODAE Meeting on Ocean Synthesis Evaluation The salinity climatology of MOVE system is relatively close to the climatology of WOA01.

9. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute New Coupled Model (JMA/MRI-CGCM) AGCM JMA/MRI Unified AGCM T L 95L40 (horizontal resol. ~ 180km) OGCM MRI.COM Ishikawa et al. (2005) 75S-75N, 0-360E horizontal resolution: lon 1.0 °, lat 0.3-1.0 ° vertical resolution : 50 levels (23 levels in the upper 200m) Coupler coupling interval : 1 hour flux adjustment for heat and momentum flux

10. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of SST in NINO3.4 ACC (NINO3.4)RMSE (NINO3.4) Period: 1979-2005 1 member forecast started from the end of every month (NOT ensemble forecast) red: JMA/MRI-CGCM blue: current operational model black: persistence (°C )

11. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of SST in WTP ACC (WTP)RMSE (WTP) Period: 1979-2005 1 member forecast started from the end of every month (NOT ensemble forecast) red: JMA/MRI-CGCM blue: current model black: persistence (°C )

12. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Experimental Setting of the Retrospective Seasonal Forecast 10-member ensemble forecasts are started from the end of January. (Two-tier AGCM forecasts are started from Feb. 10 th.) Period of the retrospective forecast is 22 years (1984-2005). CO 2 concentration is updated during the retrospective forecast period. Initial data for land model are climatology. JAN 10 members AUG 7 months Jun.-Aug. 4-month lead

13. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of Precipitation (JJA, 4 months lead) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean precipitation is verified with CMAP analysis. The JMA/MRI-CGCM shows better skill than JMA’s two-tier operational model. ACC (JMA/MRI-CGCM) ACC (Two-tier AGCM) 

14. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute SST-Precipitation Relationship in WTP in Boreal Summer Why CGCMs can predict precipitation better than AGCMs ? Temporal correlation coefficients between JJA mean precipitation and JJA mean SST from (a) CMAP and COBE-SST analysis, (b)JMA/MRI-CGCM, (c)JMA two-tier operational model. (a) Observation (b) JMA/MRI-CGCM (c) Two-tier AGCM eg. Wang et al. 2004, Wang et al. 2005, Kitoh and Arakawa 1999, Kobayashi et al. 2005 Negative Correlation

15. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of Webster-Yang Index (JJA, 4 months lead) JMA/MRI-CGCM Two-tier AGCM ACC=0.64 ACC=0.47 Webster-Yang index: U850(EQ-20N, 40-110E) – U200(EQ-20N, 40-110E) Webster and Yang (1992) 10-member ensemble Init: the end of Jan. Period:1984-2005 Ref. : JRA-25 JJA mean (m/s)

16. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of East Asian Summer Monsoon (JJA, 4 months lead) JMA/MRI-CGCM Two-tier AGCM ACC=0.58 ACC=0.04 DU2 index: U850(5-15N, 90-130E) - U850(22.5-32.5N, 110-140E) Wang and Fan (1999) 10-member ensemble Init: the end of Jan. Period:1984-2005 Ref. : JRA-25 JJA mean cf. Kug et al. (2007) (m/s)

17. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC Score of 850 hPa Temperature (upper tercile, JJA, 4 months lead) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean temperature at 850 hPa is verified with JRA-25. ROC (JMA/MRI-CGCM) ROC (Two-tier AGCM) ROC Area (tropics) : 0.59 ROC Area (tropics) : 0.65 cf. Graham et al. (2005) 

18. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Summary and Future Plans The JMA/MRI-CGCM shows better forecast skill of Nino3.4 SST than the current operational ENSO forecast model. (The ACC is more than 0.7 at a lead time of 6 months.) The JMA/MRI-CGCM shows better forecast skill of the Asian summer monsoon circulation (W-Y index and DU2 index) and precipitation compared with the current operational two-tier system. The JMA’s new coupled forecast system for ENSO prediction will be operated in early 2008. JMA now plans to improve the JMA/MRI-CGCM as a seasonal forecast model and start one-tier forecast in 2010.

19. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Thank you for your kind attention. JMA’s mascot “Harerun”

20. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute References Fujii, Y., and M. Kamachi (2003), Three-dimensional analysis of temperature and salinity in the equatorial Pacific using a variational method with vertical coupled temperature-salinity empirical orthogonal function modes, J. Geophys. Res., 108(C9), 3297, doi:10.1029/2002JC001745. Graham, R. J., M. Gordon, P. J. Mclean, S. Ineson, M. R. Huddleston, M. K. Davey, A. Brookshaw, R. T. H. Barnes (2005), A performance comparison of coupled and uncoupled versions of the Met Office seasonal prediction general circulation model, Tellus A, Volume 57, Number 3, May 2005, pp. 320-339(20) Kitoh, A, O. Arakawa (1999), On overestimation of tropical precipitation by an atmospheric GCM with prescribed SST. Geophys. Res. Lett. 26:2965-2968 Kobayashi, C., S. Maeda, A. Ito, Y. Matsushita and K. Takano (2005), Relation between SSTs and Predictability of Seasonal Mean Precipitation over the Western Tropical Pacific. JMSJ, Vol. 83, 919-929. Kug, J.-S., I.-S. Kang and D.-H. Choi (2007): Seasonal climate predictability with Tier-one and Tier-two prediction systems, Clim. Dyn., DOI 10.1007/s00382-007-0264-7 Usui, N., S. Ishizaki, Y. Fujii, H. Tsujino, T. Yasuda, M. Kamachi (2006), Meteorological Research Institute Multivariate Ocean Variational Estimation (MOVE) System: Some early results. Adv. Space Res. 37, 806-822 Wang, B. and Z. Fan (1999), Choice of South Asian summer monsoon indices. Bull. Amer. Meteor. Soc., 80, 629- 638, 1999. Wang, B., I.-S. Kang and J. -Y. Lee (2004), Ensemble Simulations of Asian-Australian Monsoon Variability by 11 AGCMs. J. Climate, 17, 4, 803-818. Wang, B., Q. Ding, X. Fu, I.-S. Kang, K. Jin, J. Shukla, and F. Doblas-Reyes (2005), Fundamental challenge in simulation and prediction of summer monsoon rainfall, Geophys. Res. Lett., 32, L15711, doi:10.1029/2005GL022734. Webster, P. J. and S. Yang: Monsoon and ENSO (1992), Selectively interactive systems. Quart. J. Roy. Meteor. Soc., 118, 877-926.

21. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute

22. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute 22 History of ENSO Monitoring and Forecast Service at JMA 1992 1996 1999 2003 2008 2010 The Second Version of JMA’s CGCM (JMA-CGCM02) Launch of ENSO Monitoring Service Start-up of Ocean Monitoring with the Operational Ocean Data Assimilation System (ODAS) Start-up of ENSO Forecast Service with the CGCM (JMA-CGCM) The New Version of JMA’s Coupled Forecast System ( MOVE-G/MRI.COM, JMA/MRI-CGCM) Seasonal Forecast with a CGCM

23. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute System design of MOVE/MRI.COM Future Past MRI.COM （ OGCM ） prediction first-guess Observation ・ temperature ・ salinity ・ SSH Coupled T-S EOF Climatology 3DVAR Gridded analysis fields IAU prediction MRI.COM POpULar Assimilation

24. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Vertical Coupled T-S EOF Modes Domain segmentation for vertical coupled T-S EOF modes Vertical coupled T-S EOF modes for a red box region Temperature SaIinity 1st 2nd 3rd 4th 5th Fujii and Kamachi (2003)

25. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Impact on the Warm Water Heat Content (WHC) WHC: Heat content in warm water (>28 °C ） WHC decreases in the thick barrier layer area because of bad barrier layer expression. BLT (Color) at Eq. WHC=10 (Black line) Difference of WHC (cal/cm 2 ) (With S correction – without S correction) Thick barrier layer area has good correspondence with the area of large WHC.

26. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Salinity Impact on the Equatorial Undercurrent With Salinity Correction 1993-2001 mean Without Salinity Correction 1993-2001 mean Eq-140W Sep96-Aug01 mean Tao With S Without S EUC is weak without S correction The profile with S correction is closer to the observed profile

27. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of SST (JJA, started from JAN) ACC (JMA/MRI-CGCM) ACC (Two-tier AGCM) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean SST is verified with COBE-SST analysis. MSSS (JMA/MRI-CGCM) MSSS (Two-tier AGCM)

28. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of SST (DJF, started from JUL) ACC (JMA/MRI-CGCM) ACC (Two-tier AGCM) 10-member ensemble forecast started from around the end of July. Period of the retrospective forecast is 22 years (1984-2005). DJF mean SST is verified with COBE-SST analysis. MSSS (JMA/MRI-CGCM) MSSS (Two-tier AGCM)

29. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of T2m (JJA, started from JAN) ACC (JMA/MRI-CGCM) ACC (Two-tier AGCM) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean T2m is verified with JRA-25. MSSS (JMA/MRI-CGCM) MSSS (Two-tier AGCM)

30. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute Forecast Skill of T2m (DJF, started from JUL) ACC (JMA/MRI-CGCM) ACC (Two-tier AGCM) 10-member ensemble forecast started from around the end of July. Period of the retrospective forecast is 22 years (1984-2005). DJF mean T2m is verified with JRA-25. MSSS (JMA/MRI-CGCM) MSSS (Two-tier AGCM)

31. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC Area of 2-m Temperature (JJA, upper tercile) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean temperature at 2 m height is verified with JRA-25. ROC Area (JMA/MRI-CGCM) ROC Area (Two-tier AGCM) ROC Area (tropics) : 0.60 ROC Area (tropics) : 0.64 cf. Graham et al. (2005)

32. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC Area of 2-m Temperature (DJF, upper tercile) 10-member ensemble forecast started from around the end of July. Period of the retrospective forecast is 22 years (1984-2005). DJF mean temperature at 2 m height is verified with JRA-25. ROC Area (JMA/MRI-CGCM) ROC Area (Two-tier AGCM) ROC Area (tropics) : 0.66 ROC Area (tropics) : 0.68 cf. Graham et al. (2005)

33. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC Area of 850 hPa Temperature (JJA, upper tercile) 10-member ensemble forecast started from around the end of January. Period of the retrospective forecast is 22 years (1984-2005). JJA mean temperature at 850 hPa is verified with JRA-25. ROC Area (JMA/MRI-CGCM) ROC Area (Two-tier AGCM) ROC Area (tropics) : 0.59 ROC Area (tropics) : 0.65

34. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute 10-member ensemble forecast started from around the end of July. Period of the retrospective forecast is 22 years (1984-2005). DJF mean temperature at 850 hPa is verified with JRA-25. ROC Area (JMA/MRI-CGCM) ROC Area (Two-tier AGCM) ROC Area (tropics) : 0.67 ROC Area (tropics) : 0.69 ROC Area of 850 hPa Temperature (DJF, upper tercile)

35. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC Area of SLP (DJF, upper tercile) 10-member ensemble forecast started from around the end of July. Period of the retrospective forecast is 22 years (1984-2005). DJF mean temperature at 850 hPa is verified with JRA-25. ROC Area (JMA/MRI-CGCM) ROC Area (Two-tier AGCM) ROC Area (tropics) : 0.5 ROC Area (tropics) : 0.6

36. Japan NOAA 32nd Annual Climate Diagnostics and Prediction Workshop, October 22-26, 2007, Tallahassee, Florida Agency Meteorological Research Institute ROC of T850 (JJA, upper tercile) 10-member ensemble forecast started from around the end of Jan. Period of the retrospective forecast is 22 years (1984-2005). DJF mean temperature at 850 hPa is verified with JRA-25. ROC (JMA/MRI-CGCM) ROC (Two-tier AGCM)