Eocene El Niño: Evidence for Robust Tropical Dynamics in the ``Hothouse''
Abstract
Much uncertainty surrounds the interactions between the El Niño-Southern Oscillation (ENSO) and long-term global change. Past periods of extreme global warmth, exemplified by the Eocene (55 to 35 million years ago), provide a good testing ground for theories for this interaction. Here, we compare Eocene coupled climate model simulations with annually resolved variability records preserved in lake sediments. The simulations show Pacific deep-ocean and high-latitude surface warming of ~10°C but little change in the tropical thermocline structure, atmosphere-ocean dynamics, and ENSO, in agreement with proxies. This result contrasts with theories linking past and future ``hothouse'' climates with a shift toward a permanent El Niño-like state.
- Publication:
-
Science
- Pub Date:
- February 2003
- DOI:
- 10.1126/science.1078766
- Bibcode:
- 2003Sci...299..877H
- Keywords:
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- ATMOS