Multi-year El Niño events tied to the North Pacific Oscillation
Ding, R.; Tseng, Y.-H.; Di Lorenzo, E.; Shi, L.; Li, J.; Yu, J.-Y.; Wang, C.; Sun, C.; Luo, J.-J.; Ha, K.-J.; Hu, Z.-Z.; Liu, F. (2022). Multi-year El Niño events tied to the North Pacific Oscillation. Nature Comm. 13(1): 3871. https://dx.doi.org/10.1038/s41467-022-31516-9
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Authors | | Top |
- Ding, R.
- Tseng, Y.-H.
- Di Lorenzo, E.
- Shi, L.
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- Li, J.
- Yu, J.-Y.
- Wang, C.
- Sun, C.
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- Luo, J.-J.
- Ha, K.-J.
- Hu, Z.-Z.
- Liu, F.
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| Abstract |
Multi-year El Niño events induce severe and persistent floods and droughts worldwide, with significant socioeconomic impacts, but the causes of their long-lasting behaviors are still not fully understood. Here we present a two-way feedback mechanism between the tropics and extratropics to argue that extratropical atmospheric variability associated with the North Pacific Oscillation (NPO) is a key source of multi-year El Niño events. The NPO during boreal winter can trigger a Central Pacific El Niño during the subsequent winter, which excites atmospheric teleconnections to the extratropics that re-energize the NPO variability, then re-triggers another El Niño event in the following winter, finally resulting in persistent El Niño-like states. Model experiments, with the NPO forcing assimilated to constrain atmospheric circulation, reproduce the observed connection between NPO forcing and the occurrence of multi-year El Niño events. Future projections of Coupled Model Intercomparison Project phases 5 and 6 models demonstrate that with enhanced NPO variability under future anthropogenic forcing, more frequent multi-year El Niño events should be expected. We conclude that properly accounting for the effects of the NPO on the evolution of El Niño events may improve multi-year El Niño prediction and projection. |
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