K. Okamoto, T. Ushio, T. Iguchi, N. Takahashi…...../ Tomoo Ushio (Osaka Prefecture University)

1. Global Satellites Mapping of Precipitation Project in Japan(GSMaP)- Microwave and Infrared combined algorithm - K. Okamoto, T. Ushio, T. Iguchi, N. Takahashi…...../ Tomoo Ushio (Osaka Prefecture University)

2. Algorithm inputs • Microwave Radiometers • TRMM/TMI from JAXA • Aqua/AMSR-E from JAXA (not included yet) • Infrared Radiometers • Global Merged Geo-IR from TSDIS

3. What, When, Where, and How do we analyze for? • Purpose: To draw the global precipitation map with 0.1 degree/1 hour resolution • What: 1hour global IR data from Goddard/DAAC and TMI/2A12 data • When: August 1 to 10, 2000 • Where: -35 to 35 in latitude, 0 to 360 in longitude • How: By interpolating precipitation between TMI overpasses using the cloud motion inferred from 1 hour IR Tb.

4. Algorithm outflow Infrared (IR) Data 10.8 μm Geo IR Present Split Window 11.4 μm Geo IR Present 1 hr Moving Vector 11.4 μm Geo IR 1 hour before Microwave Radiometer (MWR) Data Predicted GSMaP 1 hr MWR Present GSMaP Data GSMaP 1 hour before GSMaP Present

6. Typhoon JELAWAT 地域　：　太平洋北部 ＴＲＭＭ観測数　：　１２

8. Correlation between radar and the GSMaP product as a function of the past microwave satellite overpass

9. Strength and weakness of underlying assumptions • Strength • We mainly use the MWR data which is proved to be excellent for rainfall estimation. • Fast processing time (About 3 min.) for the real time operations • Weakness • Physically simple. (We do not think any phase change or so.) • Only TRMM/TMI is used. • Not use the backward process, resulting in large error. • Moving vector is not validated at all. • Any validations have not yet being done at all.

10. Planned modifications/ Improvements • Current to short term • Introduce AMSR-E in addition to TRMM/TMI by the Aonashi algorithm • Apply the Kalman filtering technique to adjust the interpolated precipitation rate between the microwave passes. • Long term • Apply the split window method by Inoue (1999) • Introduce SSM/I (F13, 14, 15) • Validation through the comparison with the radar-rain gauge network in Japan • Cross comparison with another precipitation map • Input to the global circulation model.

11. Algorithm output information • Spatial resolution 0.1 degree • Spatial coverage • -35 to 35 in latitude (TMI only) • -60 to 60 in latitude (TMI + AMSR-E) • Update frequency 1 hour • Date latency • Our product is just made, and it is not operational now. • Source of real time data/ Source of archive data • Microwave Radiometers • TRMM/TMI from JAXA • Aqua/AMSR-E from JAXA • Infrared Radiometers • Global Merged Geo-IR from TSDIS • Capability of producing retrospective data (data and resources required/ available) • Currently we would go back to the 1998 (TRMM era)

12. Radar rain gauge analysis in Japan • Current Status • Beth gave us the IDL code to process. • My student, Mr. Yasuhida Iida, read the code and made some small modification. • He could successfully draw the map for intercomparison.