Did you know that El Niño has a little brother?

Yes, El Niño does have a little brother who lives just across the South American continent in the Atlantic Ocean. His name is Atlantic Niño, and he has an uncanny resemblance to his big brother: Like El Niño, Atlantic Niño is characterized by warmer-than-average sea surface temperatures in the eastern equatorial basin and weaker-than-average trade winds throughout the east-central equatorial Atlantic.

However, there are some important differences between the two. For instance, as has been discussed in this blog, El Niño usually builds up slowly during northern summer before reaching maximum strength in late fall or winter, bringing a wide range of climate impacts throughout much of the planet. Atlantic Niño, in contrast, tends to peak in summer when ENSO is usually inactive, is usually shorter in duration, is overall much weaker than ENSO, and has more modest and local climate impacts. For example, Atlantic Niño often disrupts the West African summer monsoon, leading to reduced rainfall in the Sahel region, and is linked to increased frequency of flooding in northeastern South America and the West African sub-Sahel countries bordering the Gulf of Guinea.​