The cause of the fragile relationship between the Pacific El Niño and the Atlantic Niño

The 'Atlantic Niño' is a climate pattern similar to El Niño temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The Atlantic Niño is recognized as an important influence on Atlantic climate, probably driven by its better known Pacific counterpart, but our current ability to predict it is limited. This is particularly perplexing since the Pacific El Niño can be predicted one or two seasons in advance by the current coupled climate models. A new study suggests that the difficulty of predicting the Atlantic Niño lies in the fact that the local ocean–atmosphere interaction in the equatorial Atlantic interferes destructively with the remote influence from Pacific El Niño. This imposes a more stringent requirement on the coupled climate models; they need not only to simulate the two competing processes, but also to predict their relative strengths and their destructive interference.