Potential effect of bias correction on extreme precipitation and temperature changes over Senegal River Basin (West Africa)

Résumé

In recent climate change impact studies, bias correction is often used to overcome the well-known biases in global and regional models output. This study assesses the potential impact of bias correction on extreme precipitation and temperature of the Regional Climate Model REMO over the Senegal River Basin under the representative concentration pathways (RCP4.5 and RCP8.5). Changes in climate indices are analysed with uncorrected and bias corrected simulations over the 21^st century relative to the reference period (1971-2000). The results show in general a decrease of consecutive wet days (CWD) and an increase in the length of consecutive dry days (CDD) although slight increase of heavy rainfall is found particularly in the northern basin with similar spatial patterns of both data. Higher decadal variability of the maximum 5-day precipitation with the uncorrected in RCP8.5 is projected, while both data depicted similar variability for extremely wet days. The basin is likely to experience more warming of minimum temperature than maximum temperature. The bias correction affected mainly the magnitude of the climate change signal which was lower in the bias corrected data.