Dakar Niño variability under global warming investigated by a high-resolution regional coupled model

We have investigated an interannual variability of sea surface temperature (SST) along the northwestern African coast, so-called, Dakar Niño, and its change under global warming of highest emission scenario RCP8.5 employing a high-resolution regional coupled model. Our reginal coupled model is capable of reproducing the seasonal cycle of the SST along the northwestern African coast and its interannual variability with respect to amplitude, timing, and position of the maximized variability between 9°N-14°N from March to April. Comparing the Dakar Niño variability between the periods of 1980-2010 and 2069-2099, we found that its variability intensifies under warmer climate without changing its location and timing of maximization. The intensification is more pronounced during the Dakar Niñas (cold SST event) than during Niños (warm SST event) and the variability in ocean temperature is connected more deeply with the Dakar Niño variability (vertical motion is more strongly correlated). The stronger Dakar Niño variability and deeper connection with subsurface variability can be explained by the larger meridional wind stress variability along the northwestern African coast, which can be amplified by more enhanced land-sea thermal contrast anomaly, in the future. In addition, the ocean temperature is warmed more effectively above 40m depth where the temperature anomaly is more dominant, that is, the stratification is reinforced around 40m depth. This enhanced stratification can also cause the reinforcement of Dakar Niño/Niña variability.