Mechanisms of Global Ocean Ventilation Age Change during the Last Deglaciation

• Main Authors: Li, Lingwei, Liu, Zhengyu, Du, Jinbo, Wan, Lingfeng, Lu, Jiuyou
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: article; Verlagsveröffentlichung; Antarctic; Pacific; Antarc*; Sea ice
• Online Access: https://doi.org/10.5194/egusphere-2023-2256; https://noa.gwlb.de/receive/cop_mods_00069206; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00067603/egusphere-2023-2256.pdf; https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2256/egusphere-2023-2256.pdf

Marine radiocarbon (14C) is widely used to trace deep ocean circulation, providing insight into the atmosphere-ocean exchange of CO2 during the last deglaciation. Using two transient simulations with tracers of 14C and ideal age, we found that the oldest ventilation age is not observed at the Last Glacial Maximum (LGM). In contrast, the model shows a modestly younger ventilation age during the LGM compared to present day, mainly due to a stronger glacial Antarctic Bottom Water (AABW) transport associated with sea ice expansion. Notably, the ocean ventilation age is significantly older around 14–12 ka compared to the age at the LGM, with deep Pacific waters playing a predominant role, primarily caused by the weakening of AABW transport.