Impact of targeted dropsonde observations on the typhoon forecasts during T-PARC Hyun Mee Kim, Byoung-Joo Jung, Sung Min Kim Dept. of Atmospheric Sciences, Yonsei University International Workshop on Advancement of Typhoon Track Forecast Technique 1 Dec Tokyo, Japan

OUTLINE 1. T-PARC activity 2. SV guidance 3. OSEs 4. Summary

1. T-PARC ACTIVITY Provision of real-time adaptive observation guidance to ECMWF T-PARC DTS and JMA website Implementation of observation system experiments

Model: MM5 Adjoint Modeling System with Lancoz Algorithm Domain: 50 x 50 x 14 (120 km) Norm: Dry-TE Two fixed target region : Taiwan, Japan Moist Basic-state with simple moist linear physics 48h optimization time with 48h lead time NCEP GFS data is used for initial and boundary conditions Configuration for real-time Sensitivity Guidance 1. T-PARC ACTIVITY

UTCKorea 00z 06z 12z 18z 09 LST 15 LST 21 LST 03 LST 00z12z00z12z00z06z18z06z18z Data download SV calculation Decision Flight !!! TiTi TaTa TvTv 48 h 0h16.5h6h17.5h 6.5h Pre-processPost-process Flowchart of Real-time SV sensitivity strategy Upload product to JMA & ECMWF DTS

2. SV guidance for TC JANGMI (200815) DOTSTAR Obs

2. SV guidance for TC JANGMI (200815) UYonsei MM5SVNRL SVJMA SV ECMWF SVUMiami-NCEP ETKFUKMO ETKF 0000 UTC 27 September 2008 ※ Figures are from ECMWF DTS

Experimental design ExperimentsRun time EXPJ100 UTC 27 Sep ~ 00 UTC 28 Sep EXPJ200 UTC 28 Sep ~ 00 UTC 29 Sep EXPJ300 UTC 29 Sep ~ 00 UTC 30 Sep EXPJ400 UTC 30 Sep ~ 00 UTC 01 Oct

TESVs for TC Jangmi (200815)  Horizontal structure EXPJ1  06 SV composite +00h Shade : Total Energy distribution of SVs [ ]. Blue Contour : Divergence in 300hPa [ ]. Red Contour : Horizontal stretching (solid), Horizontal shrinking (dashed) [ ]. Vector : Radial Wind in 950hPa. A1 A1’ 1 PVU A1A1’

TESVs for TC Jangmi (200815)  Horizontal structure EXPJ3  03 SV composite +00h Shade : Total Energy distribution of SVs [ ]. Blue Contour : Divergence in 300hPa [ ]. Red Contour : Horizontal stretching (solid), Horizontal shrinking (dashed) [ ]. Angular Momentum Frontogenesis Saturated E.P.T. A3A3’ A3A3’ 1 PVU C.S.I.

TESVs for TC Jangmi (200815)  Vertical profile EXPJ1 +00h+24h_restriction +24h_whole EXPJ3 +24h_restriction+24h_whole+00h

Model systemWRF version 2.2 and WRF-VAR version 2.2 beta (Barker et al. 2004) CasesTropical Cyclone JANGMI (200815) Domain200 x 200 x 31 (30 km) in East Asia region  Modeling Systems  Physics configuration  Data used MicrophysicsWRF Single Moment (WSM) 6-class RadiationDudhia (for shortwave) / RRTM ( for longwave) CumulusNew Kain-Fritsch Land-surfaceNoah LSM Planetary boundary layerYonSei University Used observations ~ SYNOP, SHIP, BUOY, TEMP, PILOT, AMDAR, AIREP, SATEM, QSCAT, PROFL Targeted observation ~ dropsonde observations from DOTSTAR ( Wu ) NCEP FNL ~ for lateral boundary condition and initial condition in the earliest WRF forecast 3. OSEs

OSEs 3DVAR 06 UTC 26 Sep UTC UTC UTC 28 3DVAR 12 UTC 27 3 day forecast  Experimental design  3 set of OSEs

3. OSEs ALL LANDSEA ① ALL ALL-DROP ALL-QSCAT ② ALL-SATEM ③ ALL LANDLAND+SV

3. OSEs : OBS distributions 00 UTC 27 Sep06 UTC 27 Sep 12 UTC 27 Sep18 UTC 27 Sep00 UTC 28 Sep Targeted dropsonde SATEM QSCAT the others

3. OSEs : OBS distributions and Sensitivity guidance 00 UTC 27 Sep06 UTC 27 Sep 12 UTC 27 Sep18 UTC 27 Sep00 UTC 28 Sep SV criteria 1. Interpolate SV to 0.5 degree grid 2. Top 10% of grids are selected. ( a tenth of grids)

ALL, LAND, SEA 3. OSEs : ① ALL, LAND, SEA 00 UTC 27 Sep12 UTC 27 Sep00 UTC 28 Sep

ALL, ALL-DROP, ALL-QSCAT, ALL-SATEM 3. OSEs : ② ALL, ALL-DROP, ALL-QSCAT, ALL-SATEM 00 UTC 27 Sep12 UTC 27 Sep00 UTC 28 Sep

ALL, LAND, SEA, LAND+SV 3. OSEs : ③ ALL, LAND, SEA, LAND+SV 00 UTC 27 Sep12 UTC 27 Sep00 UTC 28 Sep

AnalysisForecastAnalysisForecast  In EnKF, flow-dependent forecast error covariance can be estimated with ensemble samples.  In ensemble square root filter (EnSRF), which is one of the deterministic algorithm of EnKF, apply reduced- Kalman gain for ensemble perturbations. T-∆T T T+∆T T+2∆T Case th Typhoon SINLAKU DomainD01 ~ 141x131x31 (45 km) D02 ~ 181x181x31 (15 km) 1-way nesting Model systemAdvanced Research WRF (ARW) modeling system version 2.2 (Skamarock, 2002) Analysis systemEnsemble Square Root Filter (EnSRF) for both D01 & D02 (Whitaker and Hamill, 2002; Snyder and Zhang, 2003) number of members36 Radius of Influence (ROI)1800 km (Gaspari and Cohn, 1999) Covariance relaxation coefficient0.8 (Zhang et al., 2004) Physics parameterizationmultiple physics schemes are used for ensemble members. Initial & lateral boundary perturbation Random perturbation using WRF 3DVAR CV options Configuration 3. OSEs

2008/9/8 12z 9/9 00z 9/10 00z 9/11 00z 9/12 00z 06z12z18z06z12z18z06z12z18z ExperimentsObs usedDescription EXP1SYNOP, SHIP, BUOY, TEMP, Aircraft, AMV Control experiment EXP2EXP1 + TC positionAssimilate the position (Lat, Lon) of best track EXP3EXP1 + DROP + TC positionAssimilate the targeted dropsonde and the position (Lat, Lon) of best track DescriptionType Ensemble forecast for 3 days (72 hours)Probabilistic forecast EnKF analysis with FNL bdyDeterministic forecast FNL analysis with FNL bdyDeterministic forecast DA FCST Experimental design 3. OSEs

Best track of SINLAKU from RSMC Tokyo 3. OSEs

EnKF performance ~ EXP1 verified with TEMP+DROP contemporary levels RMSE of prior ensembleRMSE of posterior ensemble Bias of prior ensembleBias of posterior ensemble Spread of prior ensembleSpread of posterior ensemble Prior ensemble spread + observational error Observational error

3. OSEs Rank Histogram ~ Reliability of ensemble Prior ensemble Posterior ensemble Without Obs Error With Obs Error Without Obs Error With Obs Error

3. OSEs Ensemble forecast ~ domain 1 initiated at 00 UTC 10 Sep 2008 EXP1 EXP2 EXP3

3. OSEs Ensemble forecast ~ domain 2 initiated at 00 UTC 10 Sep 2008 EXP1 EXP2 EXP3

4. Summary 1. We have provided the real-time SV sensitivity guidance to ECMWF DTS and JMA website during T-PARC period. 2. In the OSEs with conventional and targeted dropsonde observations, observations over the SEA area is more important than those over the LAND area in short-range track forecast of TC JANGMI(200815). 3. Among the observations over the SEA area, DROP is the most important in track forecast. 4. The SV sensitivity guidance is helpful for 1-day forecast, but the impact is reduced for 2-3 day forecast. 5. The positive impact of targeted dropsonde can be also found in ensemble forecasts. 6. More experiments for other T-PARC typhoons using other observations and data assimilation scheme are planned.