1. Shuhei Maeda Climate Prediction Division smaeda@naps.kishou.go.jp
Products of the JMA Ensemble Prediction System (EPS) for Seasonal Forecast
Shuhei Maeda
Climate Prediction Division

2. Contents 1. Introduction
2. Products of the EPS for one-month prediction
3. Products of the EPS for three-month outlook
4. Remarks

3. TCC Web page

4. One-month prediction
Three-month outlook

5. 2. Products of the EPS for one-month prediction 1) Outline of the EPS
2) Performance of the system
3) Examples of products

6. Atmospheric Model (Atmosphere-Land)
The EPS　for one-month prediction
Analysis
Atmospheric Model (Atmosphere-Land)
Products
Map
Verification
・GPV
Atmosphere
Land
Ocean
Initial
Boundary Condition
persisted SST anomaly
SST

7. Example of ensemble prediction
Initial
Spread W
Ensemble mean
Each member
7 day running mean Z500 normalized anomaly over the western North Pacific (40N,140E-170E)

8. Products Kind Forecast range Parameter Ensemble mean map 2-8day
(NH)
Z500,Z500A
T850,T850A
PSEA
PSEAA
(60N-60S and Asia)
SLP,SLPA
PSI200,PSI200A
PSI850,PSI850A
CHI200,CHI200A
T2m,T2mA
RAIN,RAINA,SSTA
＊○○○A: 　anomalies of 　　○○○

9. (continue) Products Forecast range Parameter Spread map 2-8 day
Z500A
Large anomaly index* map
Time series
(each member)
7-day running mean
Circulation indices (Z500A)
Area averaged T850A
Area averaged spread (Z500A)
CHI200 in the equatorial region
*Ratio of number of members whose anomaly is higher than 0.5SD to total number of ensemble menber at each grid point

10. 2) Performance of the system

11. Example of one-month prediction verification chartsW
Anomaly correlation scores of ensemble mean forecast in 2001
28 day (2-29) mean 500hPa height fields over the Northern Hemisphere. Initial: 2001/1/4-2001/12/27

12. W RMSE of ensemble mean forecast in 2002
28 day (2-29) mean 500hPa height fields over the Northern Hemisphere. Initial: 2002/1/3-2002/12/27

13. Example of verification of probabilistic one-month prediction
Event (E)
Z500 anomaly is greater than 0
Frequency of occurrences where E was forecast within each of the probability category bins W
Forecast frequency distribution
Reliability diagram for 7 day mean 500hPa field: day 9-15
2003 Spring (2003/2/27-5/29)

14. 3) Examples of products Prediction of ・Arctic Oscillation
・Rossby waves along Asia jet
・Intra Seasonal Oscillation in the tropics (Madden Julian Oscillation (MJO))

15. Example of one-month prediction products(1)
Ｚ５００
analysis
Ｚ５００
forecast
AO!
T850
analysis
T850
forecast W
Ensemble　average forecast　map ( Initial: 2002/10/24)
Northern Hemisphere Z500 and T850 ; 28day mean

16. Many members predict large Z500 anomaly (above 0.5*standard deviation)
Many members predict large Z500 anomaly (below 0.5*standard deviation) W
Large anomaly index map
Init: day mean ( day:2-29)

17. W
Analysis and ensemble average
Each member
Analysis
7 day running mean Z500 normalized anomaly over North western Pacific (40N,140E-170E)

18. Example of one-month prediction products(2)
Oct Nov Dec Jan
Time sequences of temperature anomalies in Japan　(5 day running mean)
Normalized　temperature anomalies W
What?

19. Prediction of the Rossby wave along Asia jet
PSI200
analysis
1/12-1/18
PSI200
forecast W
Ensemble　average forecast　map ( Initial: 2002/1/3)
PSI200 ; 7day mean (9-15 day forecast range)

20. Rossby wave guide along Asia jet
Dispersion relation of barotropic Rossby wave in U(y) is
ω＝Uk-β＊k/K2,
here, β＊ ＝ β-∂2U/ ∂y2 , K2 ＝k2+l2.
Therefore, total wave number of a stationary Rossby wave is
K＝Ks＝（ β＊/U)1/2.
Hoskins and Ambrizzi(JAS,1993,1661-) showed that if Ks has maximum at some latitude as figure 1, it works as “Rossby wave guide”
Climatological Ks in DJF (shade)
and
Analyzed stream function anomaly at 200hPa ( )
latitude
Schematic figure of Rossby wave guide

21. Temperature anomalies, and Rossby wave along Asia jet
Normalized　temperature anomalies W
Stream function (200hPa) anomalies W
Longitude and height cross section of 20N-30N averaged stream function anomaly

22. Time-longitude cross-section of stream function anomaly (20N-30N) at 200 hPa initial 2002.1.3
(left) analysis (right) ensemble mean forecast

23. Spread among ensemble membersW
Spread among ensemble members ( Initial: 2003/10/16) Z500 ; 7day mean (9-15 day )
Predicted stream function (200hPa) anomalies and wave activity flux of two of 26 ensemble member

24. Example of one-month prediction products(3)
96015
98618
Observed amount of daily precipitation in MAY 2003
97430
91425
What ??
MAY　2003

25. Eastward propagation of MJO
1-5 May
2003
6-10 May
11-15 May
16-20 May
Velocity potential (200hPa)
OLR
Velocity potential (200hPa) in the equatorial region
1 May
day
20 May W
longitude

26. Schematics of MJO 3-D structure over the Indian Ocean
Rui and Wang(1990)

27. Prediction of MJO in May 2003
Observation
2nd week prediction ( 7 day mean)
Velocity potential anomalies (200hPa)
Stream function anomalies (200hPa) W
2003/5/3-5/9
Ensemble mean
Initial:2003/4/24

28. Observation
2nd week prediction
Velocity potential anomalies (200hPa)
Stream function anomalies (200hPa) W
2003/5/10-5/16
Ensemble mean
Initial:2003/5/1

29. Observation
2nd week prediction
Velocity potential anomalies (200hPa)
Stream function anomalies (200hPa) W
2003/5/17-5/23
Ensemble mean
Initial:2003/5/8

30. Prediction of MJO in Oct. 2003
Init:10/9 2nd week
20 Sep
Obs.
day
10 Oct
CHI200a
Fcst W
Longitude
PSI850a
Velocity potential at 200hPa (CHI200)
PSI200a

31. Prediction of MJO in July 1984-1993
OBS
FCST 1 84 31 86 92 88
CHI200A in the equatorial region