Tenth International Winds Workshop 1 Observing system experiments of MTSAT-2 Rapid Scan Atmospheric Motion Vector for T-PARC 2008 using the JMA operational NWP system Koji Yamashita Japan Meteorological Agency Kobo.yamashita@met.kishou.go.jp
Tenth International Winds Workshop 2 Outline T-PARC 2008 Global and Meso-scale Experiments Specification Experimental design Trial of 2-step thinning scheme Results of OSE Summary and Future plan
Tenth International Winds Workshop 3 THORPEX Pacific Asian Regional Campaign (T-PARC 2008) Objectives Research the mechanism of genesis, recurvature and extratropical transition for tropical cyclones in the northwestern Pacific. Assess the effectiveness of Global Interactive Forecasting System (GIFS) for tropical cyclones. Improve the performance of numerical weather prediction for tropical cyclones.
Tenth International Winds Workshop THORPEX Pacific Asian Regional Campaign (T-PARC 2008) International Cooperation Project by the Asian, North American and European THORPEX Regional Committees. JMA contributed to the provision of forecast sensitivity analysis and special observations. Aircraft Dropsonde Upper-Sounding By Observatories Upper-Sounding By JMA Vessels MTSAT-2 Rapid-scan 4 Sep. 11 (36 Dropsondes) Aug. 19 12UTC 20 12UTC Aug. 19 12UTC 20 12UTC Sep. 10 12UTC 13 06UTC Sep. 17 (29) Sep. 10 12UTC 12 12UTC Sep. 10 12UTC 14 06UTC Sep. 17 12UTC 18 12UTC Sep. 28 (21) Sep. 27 12UTC 28 12UTC Sep. 27 12UTC 28 00UTC Sep. 27 12UTC 28 12UTC
Tenth International Winds Workshop Global and Meso-scale 5 Experiments Specification GSM Hydrostatic Global Spectral Model MSM Non-hydrostatic Mesoscale Model Horizontal rez./ Vertical rez. 20 km / 60 level 5 km / 60 level Top 0.1 hpa 21,800 m Inner-loop model rez. for DA 80 km 15 km Assimilation method 4D-Var 4D-Var Time windows 6 hour 3 hour Forecasts 84 hours (00,06,12,18UTC) 15 hours (00,06,12,18UTC) 33 hours (03,09,15,21UTC) Target Tropical Cyclone (TC) SINLAKU and Tropical depression (TD) From 18UTC 10/09/2008 to 06UTC 13/09/2008 From 18UTC 17/09/2008 to 12UTC 18/09/2008
Tenth International Winds Workshop SINLAKU and TD Track map 6 TD 18/9 985hPa 16/9 990hPa 19/9 980hPa 12/9 1004hPa 11/9 1008hPa 10/9 1008hPa 15/9 985hPa 14/9 975hPa 12/9 940hPa SINLAK U 17/9 990hPa 13/9 945hPa 11/9 935hPa 10/9 965hPa 9/9 990hPa 20/9 990hPa
Tenth International Winds Workshop 7 Experimental Design TEST MTSAT-2 rapid scan AMVs are assimilated. CNTL No MTSAT-2 rapid scan AMVs are assimilated. Utilization of special observations TEST CNTL MTSAT-2-RS-AMVs (use) Dropsonde and Special upper sounding (3-hourly) (no use) TC BOGUS The other observations
Tenth International Winds Workshop 8 Trial of 2-step thinning scheme for MTSAT-2 rapid scan AMVs Step 1 Equal-distance thinning with 200km (one AMV in 2deg. x 2deg. x 100hPa box) One AMV selected per box in the 6 hour time window. Step 2 Equal-distance thinning with 100km (one AMV in 1deg. x 1deg. x 100hPa box) For MTSAT-2 rapid scan AMVs (IR and WV, 4 or 7 min. intervals) One AMV selected per box in the hourly time window. Small observation error correlation MTSAT-2 Rapid Scan AMVs have as almost same accuracy as MTSAT-1R. Presented by K. Shimoji and S. HOSHINO
Tenth International Winds Workshop 9 Example of MTSAT-1R AMVs (CNTL)after QC at 300hPa in 17-19UTC 17 th September
Example of Tenth MTSAT International AMVs Winds Workshop (TEST)after 10 QC at 300hPa in 17-19UTC 17 th September Red barb : MTSAT-2-RS-47MIN Yellow barb : MTSAT-2-RS-15MIN Blue barb: MTSAT-1R
Tenth International Winds Workshop 11 Experimental results for GSM-DA
Tenth International Winds Workshop 12 Analysis and First-guess against radiosonde observations BIAS and RMAE of wind analysis for GSM-DA using MTSAT-2 rapid scan AMVs reduced. Ex. U-comp. wind speed BIAS and RMSE, and Z500 difference from 11 to 13 Sep. Anl TEST Anl CNTL Guess TEST Guess CNTL
Tenth International Winds Workshop 13 Normalized score against initial forecast ( FT=0 ) Significantly positive impacts (average ~3%) on three-day GSM forecast in Japan area. Ex. Forecast Improvement Rate wrt wrt RMSE for for 1-3 1-3 day day forecasts (CNTL-TEST)/CNTL from from 11 11 to to 13 13 Sep. Sep. in in Japan area. Statistically significant Psea T850 Z500 Wsp850 Wsp250 Forecast time (hour) Better Worse
Tenth International Winds Workshop 14 Mean TC Track Forecast Error SINLAKU track predictions were worse in the late-forecast time. But TD predictions were better. CNTL TEST TD From 11 to 12 Sep. Below 7 samples From 11 to 13 Sep. 10 samples SINLAKU From 17 to 18 Sep. 4 samples
Tenth International Winds Workshop 15 Experimental results for MSM-DA
Tenth International Winds Workshop 16 Initial forecasts against radiosonde observations RMSE above 500hPa level were reduced, where many MTSAT-2- RS-AMVs were assimilated. hpa 200 300 400 500 600 700 800 900 1000 1.5 Ex. RMSE and ME against Japan Radiosonde Wind speeds both 10-13 and 17-18 September 2008 ( FT: Forecast time ) 2.0 2.5 3.0 3.5 4.0 RMSE (m/s) TEST CNTL FT=0 Init. 00, 06,12, 18UTC hpa 200 300 400 500 600 700 800 900 1000 FT=0 TEST CNTL -0.8-0.6-0.4-0.2 0.0 0.2 ME (m/s)
Tenth International Winds Workshop 17 Equitable Threat Score against Precipitation There was a improvement of rain in one-day forecasting for precipitation over 1-15 mm per three hours around Japan. Ex. Equitable Threat Score against Radar-Rainfall composite precipitation data in Japan both 10-13 and 17-18 September 2008 (Init. 03,09,15,21UTC : Error bar : 95% confidence interval) 0.30 0.25 0.20 0.45 0.40 0.35 0.30 Ex. threshold 10mm/3hour 0.15 0.10 TEST CNTL 0.05 0 5 10 15 20 25 30 35 40 45 50 mm/3hour 0.25 0.20 0.15 3 TEST CNTL 6 9 12 15 18 21 24 27 30 33 Forecast time (hour)
Tenth International Winds Workshop 18 Mean TC Track Forecast Error SINLAKU track predictions were slightly better in the afterrecuvature stage. Another TD predictions were better. CNTL TEST TD From 11 to 12 Sep. Below 7 samples. From 11 to 13 Sep. 7 samples. SINLAKU From 17 to 18 Sep. 3 samples
Tenth International Winds Workshop 19 Summary OSEs for MTSAT-2 rapid scan AMVs using the global and meso-scale NWP system were conducted. The trial of 2-step thinning scheme for MTSAT-2 rapid scan AMVs was performed. This scheme contributed to the increase of AMVs in the vicinity of Japan where AMVs data was sparse heretofore. BIAS and RMSE of wind analysis in GSM and MSM reduced against radiosonde observations using AMVs. This better wind analysis brought the improvement of forecasts in GSM and MSM. SINLAKU track predictions were improved or neutral in GSM and MSM except the late-forecast time of GSM.
Tenth International Winds Workshop 20 Future Plan We will investigate the reason why SINLAKU track predictions were worse in GSM. We will perform more OSEs for MTSAT Rapid Scan AMVs to validate accuracy 2-step thinning scheme. Considering usage of the other satellite rapid scan AMVs ( METEOSAT-8 etc.)
Tenth International Winds Workshop 21 Thank you for your attention
Tenth International Winds Workshop 22 Back up slide
Tenth International Winds Workshop 23 Mean TC Intensity Forecast Error (GSM) SINLAKU intensity predictions were worse in the beginningforecast time in the after-recurvature stage. TD predictions were newtral. CNTL TEST TD From 11 to 12 Sep. Below 7 samples From 11 to 13 Sep. 10 samples SINLAKU From 17 to 18 Sep. 4 samples
Tenth International Winds Workshop 24 Mean TC Intensity Forecast Error (MSM) Mean TC intensity predictions were almost neutral impact. CNTL TEST TD From 11 to 12 Sep. Below 7 samples. SINLAKU From 17 to 18 Sep. 3 samples From 11 to 13 Sep. 7 samples.
Tenth International Winds Workshop MTSAT-2 Rapid Scan AMV comparison 25
Tenth International Winds Workshop 26 Case study with initial time of 18UTC 17/09/2008 20 18 TC track forecast 19 19 Slightly improvement of slow bias speed for TC track forecasts Track Forecast Error TEST CNTL
Tenth International Winds Workshop Case study with initial time of 18UTC 17/09/2008 Impact of MTSAT-2-RS-AMVs in the north or north-west side on 300 400 hpa. 27 Anl.- Guess TEST-CNTL N E W S
Tenth International Winds Workshop Case study with initial time of 15UTC 11/09/2008 for MSM 28 CNTL TEST Rader-Rainfall