An important new study published in Nature's NPJ Climate and Atmospheric Science introduces a novel technique for estimating the true age of deep ocean water. Ms. Jinbo Du, a former visiting student at The Ohio State University and currently at Peking University, led the research, which presents the Benthic minus-weighted Planktonic (BwP) radiocarbon age method, which significantly refines previous ocean age estimations from radiocarbon observations.

Among the study's co-authors were Byrd Center Principal Investigator and Max Thomas Professor of Climate Dynamics Zhengyu Liu (Geography) at The Ohio State University, and his Ph.D. student Lingwei Li, who focused on the ocean modeling components of the research.

The BwP age method was developed to overcome the limitations of traditional radiocarbon dating techniques, which often misrepresent deep ocean water ages due to complex circulation and mixing processes. Unlike conventional Benthic minus Planktonic (B-P) and Benthic minus Atmospheric (B-A) radiocarbon age methods, which are influenced by air-sea exchanges and multiple water sources, the BwP approach integrates global planktonic radiocarbon data weighted by simulated water mass contributions.

Using an advanced ocean model, the research demonstrates that the BwP age more accurately represents the true age of deep ocean water, reducing errors caused by remote water sources and temporal atmospheric radiocarbon variations. Preliminary application to the North Pacific suggests that deep water during the Last Glacial Maximum (LGM) may not have been significantly older than today, challenging previous assumptions about ocean ventilation and carbon cycles during past climate transitions.

This method enhances our understanding of deep ocean circulation and its role in the carbon cycle, particularly in historical climate changes. By accurately estimating pure ocean water age, climate models can be improved, and projections of oceanic carbon storage can be refined.

The study's findings could have significant implications for paleoclimate research. They could provide a more precise tool for reconstructing ocean ventilation history and improve our understanding of how deep ocean currents have influenced past and present climate changes.

To learn more about the study, visit Nature's NPJ Climate and Atmospheric Science.