Operational information

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Operational information

• FAO RFE for Sudan
• FAO Sudan Meteorology Authority
• Mauro Evangelisti Stefano Alessandrini (FAO
  Consultant)

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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
• FAO-RFE uses the available ground information for
  the day-based local calibration

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RFE-NOAA
ECMWF
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,
3212, 3249-3265
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FAO-RFE general scheme
Infrared meteosat data 3 km resolution
ECMWF rainfall data 25 km resolution
MPE (Eumetsat) Infrared and Microwave Estimation
3km resolution
Humidity and precipitable water profiles from
ECMWF
Interpolation
GOES Index
Daily Rainfall field 3 km resolution
Daily Rainfall field 3 km resolution
Daily Rainfall field 3 km resolution
Weighted linear combination
GTS (gauges) Rainfall data
Validated Rainfall data
Weights determination
Preliminary Combined Rainfall field 3 km
resolution
Local Calibration
Final Merged Rainfall field 3 km resolution
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FAO-RFE products
2010
1 day RFE
2007
Climatology
10D RFE
Real Time Estimate
Reference Maps
Monthly RFE
36 dekads
12 months
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FAO-RFE versions

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

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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

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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

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Case study SUDAN16 Aug 2007
Local Calibration
Station
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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
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FAO RFE (SUDAN version) 10 days 21-30/06/2011
FAO RFE (continental) 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
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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
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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.