Ocean deoxygenation is accelerating due to global warming, impacting marine ecosystems. This study uses 10 annually resolved, 200-year-long records of denitrification (a deoxygenation marker) from a North Pacific oxygen minimum zone sediment archive. Spectral analyses reveal strong signals at periodicities matching the Atlantic Multidecadal Oscillation (AMO). Modern circulation reanalyses confirm North Atlantic temperature patterns as the primary driver of oxygen variability in the tropical Pacific. Given increasing Northern Hemisphere high-latitude and North Atlantic temperatures, deoxygenation intensification is projected.

Laetitia E. Pichevin, Massimo Bollasina, Alexandra J. Nederbragt, Raja S. Ganeshram