1. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 AN INTERCOMPARISON OF GAUGE, RADAR AND SATELLITE RAINFALL IN THE TROPICS A. J. Pereira Filho 1, A. Negri 2 and P. T. Nakayama 3 1 USP, São Paulo, Brazil 2 NASA/GSFC, MD, USA 3 DAEE, São Paulo, Brazil

2. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 STUDY AREA

3. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 GAUGE DATA ACCUMULATION 1000 UTC - 1000 UTC

4. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 SPWR DATA 5 Minutes Scans 3-km CAPPI 4-bit Rainfall Rates 2-km x 2-km Resolution

5. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 SATELLITE DATA GOES-East IR 30 Minute Scans 2-bit Rainfall Rates (CST) 0.0, 2.6 and 18.9 mm h -1 4-km x 4-km Resolution

6. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 GAUGE X RADAR

7. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 GAUGE X RADAR G = Gauge Mean RG = Buck Ratio RI = Mean Ratio

8. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 GAUGE X RADAR X SATELLITE

9. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 GAUGE X RADAR X SATELLITE

10. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Highest + 

11. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Highest - 

12. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Highest Difference

13. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Stratiform

14. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Maximum Areal Mean

15. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Sampling and 2-bit Info Content

16. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 RADAR X SATELLITE Total Rainfall 1 = Ground Clutter Filtering (2 and 3) 4 = Grind Clutter Contamination 5 = Range Effect 7 = Signal Processing

17. WORKSHOP ON PRECIPITATION MEASUREMENTS MADRID 23-27 SEPTEMBER 2002 CONCLUSION Large rainfall events have relative small spatial variance Small rainfall events have relative large spatial variance Differences Radar x Satellite 70% due to phase Satellite less susceptible to systematic errors Limitations: Satellite: Information content and sampling Radar: Electronics, ground clutter, range effect,... Gauge: Representativity Next Step: Integration