Benguela Niños?
What are Benguela Niños?
Every few years the southeastern tropical Atlantic ocean is marked by large sea surface temperature (SST) deviations from its seasonal cycle. These deviations are named Benguela Niños, which are extreme and accute events occuring in the Angola-Benguela-Area (ABA, 8˚E-20˚E; 20˚S-10˚S, blue box) off the coasts of Angola and Namibia. A Benguela Niño (Niña) is an extreme warm (cold) event, characterized by warmer (colder) sea surface temperature than normal.
Figure 1. Standard deviation of the monthly mean SST anomalies calculated over the period 1982/01-2022/12. The blue box denotes the Angola-Benguela-Area.
Typically, Benguela Niños/Niñas occur in March-April-May (MAM) as shown by the seasonal cycle of the standard deviation of the ABA-averaged SST anomalies (Figure 2). The peak of variability occur at the end of the warm season (February-March-April). There is a secondary peak of SST variability in November-December, just after the cold season of July-August-September.
Figure 2. Seasonal cycle of the ABA-averaged (a) SST and (b) standard deviation of the SST anomalies using OI-SST over the period 1982-2022.
Plotting a timeseries of the detrended SST anomalies averaged over the ABA depicts the major Benguela Niños/Niñas (Figure 3). We note that since the year 2000 fewer Benguela Niños/Niñas occur as described by Prigent et al., (2020). 
Figure 3. Timeseries of the ABA-averaged detrended OI-SST anomalies. Anomalies were evaluated with respect to the climatology over the period 1982-2022. Red (blue) shades indicate that the SST anomalies is larger (smaller) than one standard deviation (0.73 ˚C).