Ken’ichi Okamoto P.I. of Global Satellite Mapping of Precipitation (GSMaP) Project in Japan

1. 2nd International GPM GV Workshop Taipei, Taiwan 27 September, 2005 GV for Japan’s Radiometer Algorithm Development Ken’ichi Okamoto P.I. of Global Satellite Mapping of Precipitation (GSMaP) Project in Japan Osaka Prefecture University

2. Research Background • High precision and high resolution global precipitation map: indispensable to global water cycle, water resource. • GEO’s visible and IR cannot measure rain rates directly and quantitatively. • Satelliteborne microwave radiometer and precipitation radar can measure rainfall rate directly and quantitatively. • Many satellites with microwave radiometers are in orbit. • TRMM version 6 algorithms, 10-15% discrepancy in monthly average rain rates by TMI and PR.

3. 1998 1999 2000 2001 2002 2003 2004 The monthly mean rain accumulations over ocean by TRMM PR and TMI(mm/month)

4. 1998 1999 2000 2001 2002 2003 2004 Percentage difference of monthly rain accumulation by TMI and PR

5. Goals of the Research Production of high precision and high resolution global precipitation map by using satelliteborne microwave radiometers. -e.g.Spatial resolution: 0.1ﾟ×0.1ﾟ, Temporal resolution: 1 day -Microwave radiometers (TMI, AMSR-E, SSM/I×3) Development of reliable microwave radiometer algorithm -Based on the common physical precipitation model which precipitation radar also uses. Precipitation map production technique for the coming GPM era.

6. Flow of the GSMaP Project Microwave Radiometer Ground Radar Obs. Gr. Ground Obs. Algorithm Gr. Verify Look-upTable Routine Obs.Campaign Obs.Data base Obs. Data Precip. Physical Model Precip. Retrieval Algorithm Precip. Physical Model Gr. ParameterSensitivity Exp. Match-upData Anal. Global Precip. Map TRMM/PR Precip. MapProducts Meteor. Satellites Obs.Data High TemporalResolution Map Global Precip. Map Gr. RadarAlgorithm Precip. MapData base Obs. Data Interpolation Algo.

7. （mm/month） （mm/month） Climatological Rain rate (GSMaP V4.5.1 TMI) （1998, 1999, 2000, 2003, 2004）

8. Comparison items • Monthly surface rainfall map • Zonally averaged, latitudinal profiles of rainfall • Zonally averaged, longitudinal profiles of rainfall • Scatter plots over selected regions • Time series, histogram and cumulative distribution analysis over selected regions • Statistically analysis based on rain types (for rain profiles information which are used for construction of lookup tables)

9. Differences of TMI – PR products (Winter) TMI Products were averaged only over PR swaths

10. Differences of TMI – PR products (Summer) TMI Products were averaged only over PR swaths

11. Zonally Averaged Rain Rate (5-yr mean, OCEAN only)

12. Zonally Averaged Rain Rate (5-yr mean, LAND only)

13. Based on EOF analysis, we selected 8 oceanic regions (upper panel) and 8 continental regions (lower panel) to compare rainfall estimates derived from GSMaP to those from PR or GPROF. 2 7 4 3 5 8 1 6 3 4 1 6 7 2 5 8

14. Scatter Plots of TMI – PR products (daily) GPROF (mm/hr) GSMaP TMI V4.5.1 (mm/hr) PR (mm/hr) PR (mm/hr) Scatter plots of 0.5° x 0. 5° PR vs GSMaP (left panel), PR vs GPROF rainfall (right panel) over the ITCZ(ocean region No.4, 150W-90W, 5N-15N) during JJA in 98-00, 03-04. Here, daily products are analyzed.

15. Time Series, Histograms and Cumulative Distributions of Rain Rate in Amazon Area PR GPROF GSMaP PR GPROF GSMaP Monthly time series of PR, GPROF, GSMaP in the Amazon area (10S-EQ, 80W-45W). PR GPROF GSMaP PR GPROF GSMaP Histogram of rain rate for PR, GPROF, andGSMaP. Cumulative distributions of rain rate by PR, GPROF, andGSMaP.

16. PR – GSMaP Comparison for Various Types of Precipitations Scatter Plots for PR – GSMaP. TYPE1-4 : LAND TYPE1: Afternoon Shower TYPE2: Shallow Convection TYPE3: Extratropical Cyclone TYPE4: Organized Convection TYPE5: Tibet TYPE1-4 : SEA TYPE6: Shallow Convection TYPE7: Extratropical Cyclone TYPE8: Organized Convection GSMaP TMI GSMaP TMI TYPE6(SEA): Shallow Convection Correlation=0.86 TYPE1(LAND): Afternoon Shower Correlation=0.64 PR PR GSMaP TMI GSMaP TMI TYPE7(SEA): Extratropical Cyclone Correlation=0.86 TYPE8(SEA): Organized Convection Correlation=0.89 PR PR

17. Infrared (IR) Data East-West Movement Present 10.8 μm GEO IR data Split Window 降水マップ作成 Present 11.4 μm GEO IR data Cloud Motion Vector for 1 hour 11.4 μm GEO data of 1 hour before South-North Movement GSMaP data GSMaP of 1 hour before Present GSMaP considering only cloud motion vector (Intermediate Map) Microwave Radiometer (MWR) data Present GSMaP MWR retrieved rain data for past 1 hour

18. Global Precipitation Map Using Microwave Radiometer Retrieved Rain Rate and IR Cloud Motion Vector

19. Typhoon Jelawat Precipitation Map Using Microwave Radiometer Retrieved Rain Rate and IR Cloud Motion Vector

20. Pilot Evaluation of High Resolution Precipitation Products (PEHRPP) University of California at IrvineJune 25, 2005 • Document, for satellite operators, the data requirements necessary to enable HRPP production and development to proceed optimally and efficiently. • Facilitate the development of improved HRPP for various applications. • Identify requirements, opportunities and uses for retrospective processing of selected HRPP. • Develop an understanding of the differences among the various HRPP and the strengths and weaknesses of each. Participants: Tim Bellerby, Dan Braithwaite, Soroosh Sorooshian, Joe Turk, Hamid Moradkhai, Yen-Ming Chiang, Farid Ishak Boushaki, Erika Coppola, Beth Ebert, George Huffman, Tomoo Ushio, John Janowiak, Yang Hong, Bisher Imam, Bob Kuligowski, Kuo-Lin Hsu, Phil Arkin

21. Daily Validation Results for Daily Precipitation Estimates (Australia)

22. Daily Validation Results for Daily Precipitation Estimates(around Japan)