Evaluation of precipitation from reanalyses and satellite products in Australia and East Asia

1. 12/12/2009 Evaluation of precipitation from reanalyses and satellite products in Australia and East Asia Gauge + Satellite Gauge only http://eos.csiro.au/ CSIRO land and Water/water for a healthy country Jorge L. Peña Arancibia, Albert I.J.M. van Dijk, Luigi J. Renzullo and Tim Raupach, all at CSIRO Mark Mulligan KCL 24 April 2012

2. Global satellite and reanalyses precipitation • Data and methods • NCEP-DOE, JRA-25, ERA-Interim, • TRMM 3B42 V6, CMORPH, PERSIANN • FD mapped ensemble precipitation • SILO (Jeffrey et al., 2001, ENVSOFT), APHRODITE SEA (Yatagai et al., 2009, SOLA) • Detection and agreement metrics for 2003–2007 (rainfall >1mm d-1). Six member statistics EGU 2012 | Evaluation of reanalyses and satellite precipitation data

3. FD mapped ensemble prob*is the probability of the value Pens on day i in the ensemble precipitation time series (Pens), Padj is the empirically adjusted precipitation time series, Pobs is the observed precipitation time series, Pens is the ensemble time series EGU 2012 | Evaluation of reanalyses and satellite precipitation data

4. Detection: occurrence of precipitation ETS How well did the forecast "yes" events correspond to the observed "yes" events (accounting for hits due to chance)? EGU 2012 | Evaluation of reanalyses and satellite precipitation data

5. Detection: occurrence of precipitation ETS ETS How well did the forecast "yes" events correspond to the observed "yes" events (accounting for hits due to chance)? Colour codes means best product: red for reanalysis and blue for satellite, ensemble black EGU 2012 | Evaluation of reanalyses and satellite precipitation data

6. Detection: occurrence of precipitation Range: -1/3 to 1, 0 indicates no skill.   Perfect score: 1. ETS EGU 2012 | Evaluation of reanalyses and satellite precipitation data

7. Agreement: quantity/timing of precipitation Correlation RMSD Pmonth Correlation Pmonth: difference in the ratio of monthly precipitation amount to total days with precipitation Pmonth RMSD EGU 2012 | Evaluation of reanalyses and satellite precipitation data

8. Agreement: quantity/timing of precipitation Correlation RMSD Pmonth Pmonth: difference in the ratio of monthly precipitation amount to total days with precipitation EGU 2012 | Evaluation of reanalyses and satellite precipitation data

9. Agreement: quantity/timing of precipitation Correlation Pmonth: difference in the ratio of monthly precipitation amount to total days with precipitation Pmonth RMSD EGU 2012 | Evaluation of reanalyses and satellite precipitation data

10. TS averaged over the entire domain RMSD ETS Pmonth Correlation EGU 2012 | Evaluation of reanalyses and satellite precipitation data

11. Summary POD: probability of detection (0-1) perfect score 1 FAR: false alarm ratio (0-1) perfect score 0 BIAS: bias in over (>1) or underdetecting (<1) perfect score 1 EGU 2012 | Evaluation of reanalyses and satellite precipitation data

12. Summary and the winner is…ensemble!!! EGU 2012 | Evaluation of reanalyses and satellite precipitation data

13. Summary and the winner is…ensemble!!! But not a fair comparison!!! EGU 2012 | Evaluation of reanalyses and satellite precipitation data

14. Conclusion • Similar findings to other studies in different geographical domains (e.g. Ebert et al., 2007 BAMS) • Other sources of error • Enhancement of metrics when producing ensembles • Importance of ground monitoring networks, particularly were satellite/reanalysis algorithms need refinement and evaluation • More confidence in areas were ground monitoring is scarce • HS1 A276 poster Tuesday 24 EGU 2012 | Evaluation of reanalyses and satellite precipitation data

15. http://eos.csiro.au/ • HS1 A276 poster EGU 2012 | Evaluation of reanalyses and satellite precipitation data

16. Thank you • CSIRO Land and Water Jorge Luis Peña Arancibia t +61 2 6246 5711 e jorge.penaarancibia@csiro.au w www.csiro.au CSIRO Land and water