Glacial carbon cycle changes by Southern Ocean processes with sedimentary amplification ...

• Main Authors: Kobayashi, Hidetaka, Oka, Akira, Yamamoto, Akitomo, Abe-Ouchi, Ayako
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Southern Ocean
• Online Access: https://dx.doi.org/10.57757/iugg23-2141; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018661

<!--!introduction!--> Recent paleo reconstructions suggest that increased carbon storage in the Southern Ocean during glacial periods contributed to low glacial atmospheric carbon dioxide concentration (pCO2). However, quantifying its contribution in three-dimensional ocean general circulation models (OGCMs) has proven challenging. Here, we show that OGCM simulation with sedimentary process considering enhanced Southern Ocean salinity stratification and iron fertilization from glaciogenic dust during glacial periods improves model-data agreement of glacial deep water with isotopically light carbon, low oxygen, and old radiocarbon ages. The glacial simulation shows a 77-ppm reduction of atmospheric pCO2, which closely matches the paleo record. The Southern Ocean salinity stratification and the iron fertilization from glaciogenic dust amplified the carbonate sedimentary feedback, which caused most of the increased carbon storage in the deep ocean and played an important role in pCO2 reduction. The ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...