Enhanced El Niño-Southern Oscillation variability in recent decades

Pamela R. Grothe; Kim M. Cobb; Giovanni Liguori; Emanuele Di Lorenzo; Antonietta Capotondi; Yanbin Lu; Hai Cheng; R. Lawrence Edwards; John R. Southon; Guaciara M. Santos; Daniel M. Decampo; Jean Lynch-Stieglitz; Tianran Chen; Hussein R. Sayani; Diane M. Thompson; Jessica L. Conroy; Andrea L. Moore; Kayla Townsend; Melat Hagos; Gemma O’Connor; Lauren T. Toth

doi:10.1029/2019gl083906

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Enhanced El Niño-Southern Oscillation variability in recent decades

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Abstract

The El Niño–Southern Oscillation (ENSO) represents the largest source of year-to-year global climate variability. While Earth system models suggest a range of possible shifts in ENSO properties under continued greenhouse gas forcing, many centuries of preindustrial climate data are required to detect a potential shift in the properties of recent ENSO extremes. Here we reconstruct the strength of ENSO variations over the last 7,000 years with a new ensemble of fossil coral oxygen isotope records from the Line Islands, located in the central equatorial Pacific. The corals document a significant decrease in ENSO variance of ~20% from 3,000 to 5,000 years ago, coinciding with changes in spring/fall precessional insolation. We find that ENSO variability over the last five decades is ~25% stronger than during the preindustrial. Our results provide empirical support for recent climate model projections showing an intensification of ENSO extremes under greenhouse forcing.

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Pamela R. Grothe, Kim M. Cobb, Giovanni Liguori, Emanuele Di Lorenzo, Antonietta Capotondi, Yanbin Lu, Hai Cheng, R. Lawrence Edwards, John R. Southon, Guaciara M. Santos, Daniel M. Decampo, Jean Lynch-Stieglitz, Tianran Chen, Hussein R. Sayani, Diane M. Thompson, Jessica L. Conroy, Andrea L. Moore, Kayla Townsend, Melat Hagos, Gemma O’Connor, Lauren T. Toth. 2020-04-04. Enhanced El Niño-Southern Oscillation variability in recent decades. https://doi.org/10.1029/2019gl083906

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