Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans

Maureen Walczak; Alan Mix; Ellen Cowan; Stewart Fallon; Keith Fitfield; Jay R. Alder; Jianghui Du; Brian Haley; Tim Hobern; June Padman; Summer K. Praetorius; Andreas Schmittner; Joseph Stoner; Sarah Zellers

doi:10.1126/science.aba7096

USGS · 70217122

Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans

Maureen Walczak·Alan Mix·Ellen Cowan·Stewart Fallon·Keith Fitfield·Jay R. Alder·Jianghui Du·Brian Haley·Tim Hobern·June Padman·Summer K. Praetorius·Andreas Schmittner·Joseph Stoner·Sarah Zellers

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Abstract

New radiocarbon and sedimentological results from the Gulf of Alaska document recurrent millennial-scale episodes of reorganized Pacific Ocean ventilation synchronous with rapid Cordilleran Ice Sheet discharge, indicating close coupling of ice-ocean dynamics spanning the past 42,000 years. Ventilation of the intermediate-depth North Pacific tracks strength of the Asian monsoon, supporting a role for moisture and heat transport from low latitudes in North Pacific paleoclimate. Changes in carbon-14 age of intermediate waters are in phase with peaks in Cordilleran ice-rafted debris delivery, and both consistently precede ice discharge events from the Laurentide Ice Sheet, known as Heinrich events. This timing precludes an Atlantic trigger for Cordilleran Ice Sheet retreat and instead implicates the Pacific as an early part of a cascade of dynamic climate events with global impact.

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Maureen Walczak, Alan Mix, Ellen Cowan, Stewart Fallon, Keith Fitfield, Jay R. Alder, Jianghui Du, Brian Haley, Tim Hobern, June Padman, Summer K. Praetorius, Andreas Schmittner, Joseph Stoner, Sarah Zellers. 2020. Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans. https://doi.org/10.1126/science.aba7096

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