Nd isotope data and linear mixing model output for U1541

The mid-Pleistocene transition (MPT; between ~1.25 to 0.7 million years ago [Ma]) marks when Earth's glacial pacing switched from 41,000-year to 100,000-year cyclicity. Here, we present a South Pacific hydrogenous neodymium isotope record tracking changes in deep ocean circulation spanning 1.5–0.5 Ma. This record indicates that the MPT was not triggered by Northern Hemisphere (NH) processes. Instead, the growth of Antarctic Ice Sheets to a critical size (~1.8 Ma) primed the climate system for the MPT, with iceberg release and melting transferring buoyancy out of the Southern Ocean. This iceberg-associated buoyancy redistribution ultimately reduced deep water formation in the NH, an observation supported by our data. Once the MPT was initiated in the Southern Hemisphere, its subsequent climatic changes were dominated by NH processes. This dataset has multiple tables. Table S1: Nd isotope record of U1541 Table S2: Model output of Northern Component Water fraction Table S3: Model output of Pacific Deep Water fraction Table S4: Model output of N. Atlantic end-member eNd Table S5: Model output of N. Pacific end-member eNd Table S6: Model output of N. Atlantic end-member Nd concentrations (pmol/kg) Table S7: Model output of N. Pacific end-member Nd concentrations (pmol/kg)