Simulating the connections of ENSO and the rainfall regime of East Africa and the upper Blue Nile region using a climate model of the Tropics
We simulate the observed statistical relationship between ENSO and the rainfall regime of the upper Blue Nile using the tropical-band version of the regional climate model RegCM4 (or Reg-TB). An ensemble of nine simulations for the 28-year period 1982–2009 is completed to investigate the role of ENS...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2014-11-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | http://www.hydrol-earth-syst-sci.net/18/4311/2014/hess-18-4311-2014.pdf |
| Summary: | We simulate the observed statistical relationship between ENSO and the
rainfall regime of the upper Blue Nile using the tropical-band version of the
regional climate model RegCM4 (or Reg-TB). An ensemble of nine simulations for
the 28-year period 1982–2009 is completed to investigate the role of ENSO in
modulating rainfall over the upper Blue Nile catchment. Reg-TB shows a good
skill in simulating the climatology of temperature, outgoing long-wave
radiation patterns as well as related atmospheric circulation features during
the summer season (i.e. the rainy season over the Blue Nile catchment). The
model also succeeds in reproducing the observed negative correlation between
Pacific SST and rainfall anomalies over the Blue Nile catchment, and in
particular the association of droughts over the Blue Nile with El Niño events
that start in April–June. We thus propose that observations and model
forecasts of Pacific SST during this season could be used in seasonal
forecasting of summer rainfall over the upper Blue Nile region. |
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| ISSN: | 1027-5606 1607-7938 |