3. Products of the EPS for three-month outlook 1) Outline of the EPS 2) Examples of products 3) Performance of the system

The EPS for three-month outlook Atmospheric model (Atmosphere- Land) SST persisted SST anomaly Initial Atmosphere Land Ocean Products Guidance Map …... Analysis BoundaryCondition

What can a model predict ? Where does the signal of long-range forecast come from ? Response of atmosphere to the slowly varying boundary conditions Especially, SST anomalies in the tropics such as ENSO → Anomalies of large scale convective activity → Anomalies of large scale divergence flow → Anomalies of tropical circulation direct and indirect influence on the circulation in the mid- and high- latitudes

u,v,w Kelvin Wave Rossbywave u, v, p in the low level * tropical circulation is depicted approximately. Symmetric heating on the equator Linear response on heating in the tropics : Matsuno-Gill response Gill.A.E.(1980) QJRMS,447 - Heating L L

W Circulation anomalies associated with ENSO (DJF) Stream function at 200hPa Stream function at 850hPa OLR Composite Map in El-Nino years

W Example of three-month outlook products(1) DJF 2002/03 Init:2002/11/10 OBS FCST and Error Precipitation anomalies Stream function anomalies at 200hPa Error of Stream function anomalies at 200hPa

Example of three-month outlook products(2) ( Very Cold in the Indochina Peninsula) W

Example of three-month outlook products(2) ( Very Cold in the Indochina Peninsula) Init:1999/11/30 Precipitation anomalies Stream function anomalies at 850hPa OBS FCST

W Example of three-month outlook products(3) DJF 2003/04 Init:2003/11/15 SSTA Precipi- tation Velocity potential at 200hPa Stream function at 200hPa at 850hPa

Configuration of Seasonal forecast experiment (Hindcast) Model : JMA AGCM(T63v0103) Target years : 1984 to 2001, 18 years Target months : All months ( initial date is the end of every month) Integration time : Four months Atmospheric initial condition : ERA-15 from 1984 to 1993, and JMA’s operational global analyses from 1994 to 2001 Land surface initial condition : Land surface initial condition: Output from SiB forced by ERA-15 from 1984 to 1993, and 10- year average of them for 1994 to 2001 SST : Anomaly at initial date is persisted during the forecast period Ensemble size : Five members

Verification of circulation fields (Z500) 13-months running mean :above 0.5 :above 0.4 El Nino La Nina Anomaly correlation scores (ACC) of 90 day mean 500hPa geopotential height at forecast range for all cases ( ). North Pacific(20N-90N,90E-90W) region W

Verification of circulation fields (Z500) All cases ENSO years ( top left): Nrothern Hemisphere (20N-90N) (top right): Eurasia (20N-90N,0-180E) (bottom left):North Pacific (20N-90N,90E-90W) (bottom right) East Asia (20N-60N,90E-170E) Month to month variation of anomaly correlation scores (ACC) of 90 day mean 500hPa geopotential height at forecast.

W Verification of temperature at 2m and precipitation Standard Verification System (SVS) for Long-range Forecast T2m JAS (init:5/31) Precipitation MSSS Corre lation

Could the model predict summer season climate in Asia and Pacific region?

Prediction of precipitation in summer (JJA) Distribution of interannual temporal correlation coefficients between observed (CMAP) and model ensemble average forecast precipitation for 18 years ( ). Initial: 30 April Forecast range: day (90 day mean)

Prediction of precipitation in the western North Pacific summer monsoon (WNPM) region ( E,10-20N) Day: Initial:4.30 Interannual variations of observed and model precipitation anomaly in the western North Pacific summer monsoon region ( E,10- 20N) in JJA Observation Ensemble average Marks Each forecast

(Relationship between activities of WNPM and lower tropospheric circulation) Distribution of interannual temporal correlation coefficients between area averaged precipitation(110E-160E,10N- 20N) and stream function at 850hP in JJA for 18 years ( ).

Observation Ensemble average Marks Each forecast Interannual variations of observed and model 850hPa vorticity anomaly in NPSH region ( E,10-30N) Initial: 30 April forecast range: day Prediction of westward extension of North Pacific subtropical High in summer Lu and Dong(JMSJ,2001)

Prediction of summer (JJA) in 1998 Precipitation observation forecast PSI850 observation forecast Initial: 31 May 1998 Forecast range: 1-90 day

Remarks 1) Prediction skills should be checked before you use the products. 2) Improvement of the EPS for seasonal forecast is required.