Journal des sciences de la Terre et du changement climatique

Abstrait

An Assessment of Temperature and Precipitation Change Projections using a Regional and a Global Climate Model for the Baro-Akobo Basin, Nile Basin, Ethiopia

Asfaw Kebede, Bernd Diekkrüger and Semu A. Moges

In this study, large-scale atmospheric output variables from CGCM3.1 global circulation model and the regional model REMO are downscaled statistically to meteorological variables at the point scale in a daily resolution to assess future climatic variables under climate changes. The area of study is Baro-Akobo river basin in Ethiopia, which contributes to the White Nile in Sudan. The minimum and maximum temperature and precipitation variables were selected, and future time scenarios of these variables were projected based on climate scenarios of A1B and B1 for a period of 2011 to 2050.Both REMO and CGCM3.1 outputs capture the observed 20th century trends of temperature and precipitation change over the basin. However, the result of downscaled precipitation reveals that precipitation does not verify a systematic increase or decrease in all future time horizons for both A1B and B1 scenarios unlike that of maximum temperature. For REMO A1B and B1 scenarios similar trend +1.3°C changes for maximum temperature are expected, and rainfall increases as much as 24% for the 2011 to 2050 period. For the CGCM3.1 model +2.55°C changes in maximum temperature and 23% increase in rainfall is likely.