Upwelling intensification as part of the Pliocene-Pleistocene climate transition

A deep-sea sediment core underlying the Benguela upwelling system off south west Africa provides a continuous time series of sea surface temperature (S ST) for the past 4.5 million years. Our results indicate that temperatures in the region have declined by about 10 degreesC since 3.2 million years ag o, Records of paleoproductivity suggest that this cooling was associated wi th an increase in wind-driven upwelling tied to a shift from relatively sta ble global warmth during the mid-Pliocene to the high-amplitude glacial-int erglacial cycles of the Late Quaternary, These observations imply that Atla ntic Ocean surface water circulation was radically different during the mid -Pliocene.