Of all of the atmospheric patterns that affect us here in the Southeast, the one that makes the most statistically predictable impacts on our climate is the El Niño-Southern Oscillation. When an El Niño is forecast to occur, we know with a fair degree of confidence what kind of climate to expect while it is most intense, which is usually in the winter months. But it had impacts on other seasons too, and that can help us plan for the kinds of weather patterns that are most likely to occur when an El Niño or La Niña occur.
This week a new study was published looking at the past 400 years of ENSO fluctuations using tropical coral, which can capture changes in climate by its growth patterns (similar to growth rings in trees). The study showed that in most of the past 400 years, the El Niños were equally divided between events with the strongest warming in the Eastern Pacific (EP) and events with the strongest warming in the Central Pacific (CP). However, in recent years the proportion of CP events has become much larger, which EP events are less frequent but more intense when they do occur. Scientists are now looking for linkages between global warming and the change in the frequency of EP and CP events.
You can read a good general discussion of this at The Conversation here. The story of how the scientists did the work can be found at Nature Ecology here. The original paper can be found at Nature Geoscience here.
