1. CHG rainfall products Make best possible rainfall products for monitoring crop stress in areas of rain fed agriculture. Objectives:

2. CHG rainfall products Make best possible rainfall products for monitoring crop stress in areas of rain fed agriculture. Results: Objectives: CHIRP (1981 - present) and FTIP (2000 - present) Global unbiased 0.05 degree pentads available with 2 day lag tinyurl.com/chg-products

3. CHG rainfall products Make best possible rainfall products for monitoring crop stress in areas of rain fed agriculture. Improved Results: Objectives: CHIRP/FTIP blended with station data, 1 pentad lag Results: CHIRP (1981 - present) and FTIP (2000 - present) Global unbiased 0.05 degree pentads available with 2 day lag tinyurl.com/chg-products

4. Quick overview of how we get there… Start with long term monthly average rainfall maps FCLIM Aside: build monthly models of rainfall trained on TRMM-V7 –derive coefficients a and b, such that rain rate = a * CCD + b (IRP) –where CCD is the percentage of observation where IR temp < threshold Calculate IRP pentads from CPC IR data (2000 - present) and B1 IR data (1981 - 2008) CHIRP (1981-present) = FCLIM * (IRP %normal) Use TRMM-RT7 data (2000 - present) FTIP (2000-present) = FCLIM * (IRP %normal + TRMM-RT7 %normal)/2 SPACE TIME

5. CHIRP 2012.09.6 0.05º, global, unbiased, rainfall pentad [mm] with 2 day lag.

6. FTIP 2012.09.6 0.05º, global, unbiased, rainfall pentad [mm] with 2 day lag.

7. FCLIM derived wet season JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ DJF

8. Validation analysis for each data set to validate, CHIRP, FTIP, TRMM, ECMWF… build cubes of 2 month totals based on growing season. Season time series (2001 – 2011) JFM [J1+F1, J1+M1, F1+M1, …, J11+F11, J11+M11, F11+M11]... JAS [J1+A1, J1+S1, A1+S1, …, J11+A11, J11+S11, A11+S11]... NDJ [N1+D1, N1+J2, D1+J2, …, N11+D11, N11+nan, D11+nan] longitude latitude time series longitude latitude time series ‘True’ FTIP correlation bias ratio mean absolute error misses

9. Correlation with interpolated stations -0.5 0.0 0.5 0.7 1.0 TRMM-RT7 ECMWF CHIRP FTIP

10. Bias ratio to interpolated stations 0.0 0.5 0.8 1.2 1.5 >1.5 TRMM-RT7 ECMWF CHIRP FTIP

11. Mean Absolute Error with interpolated stations 0 40 60 100 >100 TRMM-RT7 ECMWF CHIRP FTIP

12. Misses compared to interpolated stations 0 1 4 9 >9 TRMM-RT7 ECMWF CHIRP FTIP

13. CHG Station Climate Database Daily rainfall observations from many public and private sources going back to the 1800’s Currently ~950,000 records in db Used to create spatially interpolated fields Challenge identifying duplicates, non-zero zeroes Constantly topping off db from available sources Blended into satellite rainfall products

14. January 2009 Original

15. January 2009 Fixed

16. B1 fails 2

17. B1 fails 3

18. Summary 2 rainfall products, CHIRP (1981-present) & FTIP (2000-present) Global, 0.05 º, unbiased, pentads with 2 day lag. Compare very well with existing rainfall products. Developing an extensive station rainfall database Used to blend station data with CHIRP and FTIP

19. Thank You … Chris Funk Greg Husak Joel Michaelsen Diego Pedreros Andrew Verdin Marty Landsfeld Boleslo Romero FEWS NET Data available via anonymous ftp: tinyurl.com/chg-products

20. CHG Rainfall Product Paths FCLIM CHG Stations database FTIPS 2005-prst, 5Km, 5days CCD model IRP 2000- prnt BIRP 1980- 2008 Join 80-prst CHIRP CHIRPS 1980-present, 5Km, 5days FTIP FCLIMS, 1920 present, 5Km, 5days Source Datasets Station Average monthly rainfall Rainfall predictors TRMM7-RT 2000-prsnt IR-B1 1980-2008 CPC-IR – 2000-prsnt TRMMV7 1998-present