El Niño–Southern Oscillation–like variability during glacial terminations and interlatitudinal teleconnections

Abstract

Interannual‐decadal variability in the equatorial Pacific El Niño–Southern Oscillation (ENSO) induces climate changes at global scale, but its potential influence during past global climate change is not yet well constrained. New high‐resolution eastern equatorial Pacific proxy records of thermocline conditions present new evidence of strong orbital control in ENSO‐like variability over the last 275,000 years. Recurrent intervals of saltier thermocline waters are associated with the dominance of La Niña–like conditions during glacial terminations, coinciding with periods of low precession and high obliquity. The parallel dominance of δ13C‐depleted waters supports the advection of Antarctic origin waters toward the tropical thermocline. This “oceanic tunneling” is proposed to have reinforced orbitally induced changes in ENSO‐like variability, composing a complex high‐ and low‐latitude feedback during glacial terminations.