1. Niamey, Niger, 1 st June 2007 La prevision saisonniere avec l’outil CPT By: Ousmane NDIAYE

2. Les bases de la prevision saisonnieres?

3. Forcage de la SST sur le climat  Ocean 2/3 de la surface de la terre  forte capacite thermique :  source de vapeur d’eau precipitable  Dynamique : circulation –El Nino

4. Rationale for seasonal prediction: slower evolution of the oceanic component of the climate sytem SST on tropical atmosphere

5. Comment cela marche alors ?

6. Atmospheric General Circulation Model SEA SURFACE TEMPERATURE ATMOSPHERIC CONDITIONS Coupled Ocean and Atmosphere GCM AtmosphereOcean  Atmospheric conditions  Ocean conditions Model Output Statistics (Statistical Correction) Observed : yield/rainfall OceanAtmosphere SSTAGCM STATISTICAL RELATIONSHIP SEA SURFACE TEMPERATURE PREDICTION : Rainfall, humidity… Observed Rainfall/crop yield

7. Modele de prevision statistique: regression

8. Comment ca fonctionne ? Y Y 50 Y 51 Y 52 Y 99 Y 98 Y 97 Y 96 YkYk Y k+1 Y k-1 Y 53 X X 50 X 51 X 52 X 99 X 98 X 97 X 96 XkXk X k+1 X k-1 X 53 Y = a*X + b time Predictand (rainfall) Predictor (SST) (a,b) ? a*X + b observee prevue Periode 1 Periode 2 Tres tres simple : Ŷ + e

9. La Validation croisee sur une fenetre d’une annee

10. Prevision Retro-spective/active

11. Climate Predictability Tool : CPT

12. The Climate Predictability Tool (CPT) provides a Windows package for :  seasonal climate forecasting  model validation  actual forecasts given updated data Uses ASCII input files : GCM, Stations, Indices Options :  principal components regression (PCR)  canonical correlation analysis (CCA) Help Pages on a range of topics in HTML format Options to save outputs in ASCII format and graphics as JPEG Program source code is now available for those using other systems (e.g., UNIX) OVERVIEW

13. 1. STATION files: This file-type contains : Station_name (without spaces;  16 characters) Latitude (in signed degrees) Longitude (signed degrees) Year (in the first column) Data (missing values should be filled with the same value, -9999 for example) Keywords: STN, LAT, LONG CPT INPUT FILE FORMATS

14. For further details, read the help page of each menu and option. Subscribe to the user-list to be advised of updates: http://iri.columbia.edu/outreach/software/ We want to hear from you. Your comments and questions help us to improve the CPT so do not hesitate to write to us at: cpt@iri.columbia.edu CONCLUSIONS