Operational information FAO RFE for Sudan FAO & Sudan Meteorology Authority Mauro Evangelisti &Stefano Alessandrini (FAO Consultant)

What is FAO-RFE? FAO-RFE is a system that collects, stores, processes several basic data to estimate the rainfall over an area with limited ground information day-based local calibration FAO-RFE uses the available ground information for the day-based local calibration

Residuals for NDVI computed as a function of (a) RFE and (b) ECMWF. The residuals can be interpreted directly as rainfall over- or underestimations. Areas with less than 200 mm of average annual rainfall and water bodies have been masked out (in white). O. Rojas, F. Rembold, J. Delincé & O. Léo (2011): Using the NDVI as auxiliary data for rapid quality assessment of rainfall estimates in Africa, International Journal of Remote Sensing, 32:12, RFE-NOAA ECMWF

FAO-RFE general scheme Infrared meteosat data ~ 3 km resolution GOES Index Humidity and precipitable water profiles from ECMWF Daily Rainfall field 3 km resolution ECMWF rainfall data ~ 25 km resolution Daily Rainfall field 3 km resolution Weighted linear combination GTS (gauges) Rainfall data Weights determination Preliminary Combined Rainfall field 3 km resolution Final Merged Rainfall field 3 km resolution MPE (Eumetsat) Infrared and Microwave Estimation 3km resolution Daily Rainfall field 3 km resolution Validated Rainfall data Interpolation Local Calibration

FAO-RFE products 1 day RFE 10D RFE Monthly RFE Climatology 36 dekads12 months Reference Maps Real Time Estimate

FAO-RFE versions FAO-RFE is available at two levels: –continental –country-based (e.g. Sudan)

FAO-RFE customization Customization works at several levels: –input data –forecast model –00Z or 06Z based –algorithms –already existing work flow –output formats –user interface

Difference between FAO RFE (continental product) and FAO RFE at country level At the country level GTS measurements can be used together with local data So, at the country level both the global calibration and the local calibration are performed only with specific measurements over a territory with a limited extension. At the continental level the calibration processes are performed over a larger area, including stations far from the country and this can result in a loss of reliability for a specific country At the country level all the power has been given to the measurements and the RFE daily estimate is forced to be equal to the measurements at the gauges locations At the continental level we have less control about the quality of the measurements therefore some rainfall data are rejected (if is to much different from the RFE estimate) and the local calibration forces less strongly the RFE estimate towards the measured data

Case study SUDAN:16 Aug 2007 Station Local Calibration

FAO-RFE user interface - Time Aggregation Selector - Reference Maps Viewer - Zoom facilities - Point and Click query - Regular (lat,lon) grids output at different resolutions in GeoTiff and Idrisi Raster

FAO RFE (continental) 10 days 21-30/06/2011 FAO RFE (SUDAN version) 10 days 21-30/06/2011 The estimate done at National level using more station data leads to a lower rainfall values in general over Sudan territory The effect is more evident on a 10 days period

FAO RFE (continental) Monthly 06/2011 FAO RFE (SUDAN version) Monthly 06/2011 The estimate done at National level using more station data lead to a lower rainfall values in general over Sudan territory

Advantage of FAO-RFE The main advantage will be for the country that will be able to do/manage his own rainfall estimates incentive of improvement of network stations The country will has the possibility to improve it when more meteorological stations will be available The accuracy should be high when compare with the methodological approaches that only considerer the GTS stations.