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

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  • Products of the JMA Ensemble Prediction System (EPS)for Seasonal ForecastShuhei MaedaClimate Prediction Division smaeda@naps.kishou.go.jp

  • Contents1. Introduction

    2. Products of the EPS for one-month prediction 3. Products of the EPS for three-month outlook

    4. Remarks

  • TCC Web pagehttp://cpd2.kishou.go.jp/tcc/

  • One-month predictionThree-month outlook

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

  • The EPSfor one-month predictionAtmospheric Model (Atmosphere-Land)SSTpersisted SST anomaly InitialProducts Map VerificationGPVAnalysisBoundary Condition

  • 7 day running mean Z500 normalized anomaly over the western North Pacific (40N,140E-170E)Ensemble meanSpreadEach memberExample of ensemble predictionInitialW

  • ProductsA: anomalies of

    KindForecast rangeParameter

    Ensemble mean map2-8day9-15day16-29day2-29day(NH)Z500,Z500AT850,T850APSEAPSEAA(60N-60S and Asia)Z500,Z500ASLP,SLPAPSI200,PSI200APSI850,PSI850ACHI200,CHI200AT2m,T2mARAIN,RAINA,SSTA

  • (continue) Products*Ratio of number of members whose anomaly is higher than 0.5SD to total number of ensemble menber at each grid point

    Forecast rangeParameter

    Spread map2-8 day9-15 day16-29 day2-29 dayZ500A

    Large anomaly index* mapTime series (each member)7-day running meanCirculation indices (Z500A)Area averaged T850AArea averaged spread (Z500A)CHI200 in the equatorial region

  • 2) Performance of the system

  • Example of one-month prediction verification chartsAnomaly 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 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 W

  • Example of verification of probabilistic one-month prediction Reliability diagram for 7 day mean 500hPa field: day 9-152003 Spring (2003/2/27-5/29) Frequency of occurrences where E was forecast within each of the probability category binsEvent (E)Z500 anomaly is greater than 0 Forecast frequency distributionW

  • 3) Examples of productsPrediction of Arctic Oscillation Rossby waves along Asia jet Intra Seasonal Oscillation in the tropics (Madden Julian Oscillation (MJO))

  • Ensembleaverage forecastmap ( Initial: 2002/10/24)Northern Hemisphere Z500 and T850 ; 28day meananalysisforecastT850analysisT850forecastWAO!Example of one-month prediction products(1)

  • Large anomaly index mapInit:2002.10.24 28 day mean ( day:2-29)Many members predict large Z500 anomaly (above 0.5*standard deviation) Many members predict large Z500 anomaly (below 0.5*standard deviation) W

  • 7 day running mean Z500 normalized anomaly over North western Pacific (40N,140E-170E)W

  • Normalizedtemperature anomalies 2002.1.11-15Time sequences of temperature anomalies in Japan(5 day running mean) 2001.10-2002.1Oct Nov Dec JanExample of one-month prediction products(2) WWhat?

  • Ensembleaverage forecastmap ( Initial: 2002/1/3)PSI200 ; 7day mean (9-15 day forecast range)PSI200analysisPSI200forecastWPrediction of the Rossby wave along Asia jet1/12-1/18

  • Rossby wave guide along Asia jetDispersion relation of barotropic Rossby wave in U(y) is Uk-k/K2, here, -2U/ y2 , K2 k2+l2.Therefore, total wave number of a stationary Rossby wave is KKs /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 guideSchematic figure of Rossby wave guideClimatological Ks in DJF (shade)andAnalyzed stream function anomaly at 200hPa (2002.1.11-15)latitude

  • Temperature anomalies, and Rossby wave along Asia jetNormalizedtemperature anomaliesLongitude and height cross section of 20N-30N averaged stream function anomaly 2002.1.11-15Stream function (200hPa) anomaliesWW

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

  • WSpread among ensemble members 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

  • 1 10 20 30 Example of one-month prediction products(3) MAY2003 Observed amount of daily precipitation in MAY 200396015974309861891425What ??

  • Eastward propagation of MJO 1-5 May20036-10 May11-15 May16-20 MayOLR Velocity potential (200hPa) longitudeday1 May20 MayWVelocity potential (200hPa) in the equatorial region

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

  • WPrediction of MJO in May 2003 Observation2nd week prediction ( 7 day mean) Velocity potential anomalies (200hPa)Stream function anomalies (200hPa)Ensemble meanInitial:2003/4/242003/5/3-5/9

  • WVelocity potential anomalies (200hPa)Stream function anomalies (200hPa)Observation2nd week predictionEnsemble meanInitial:2003/5/12003/5/10-5/16

  • WVelocity potential anomalies (200hPa)Stream function anomalies (200hPa)2nd week predictionObservationEnsemble meanInitial:2003/5/82003/5/17-5/23

  • WPrediction of MJO in Oct. 2003Velocity potential at 200hPa (CHI200)Longitude day20 Sep10 OctObs.FcstInit:10/9 2nd weekCHI200aPSI850aPSI200a

  • Prediction of MJO in July 1984-1993OBSFCSTCHI200A in the equatorial region 84868892131