Deglacial Subantarctic CO2 outgassing driven by a weakened solubility pump

• Published in: Nature Communications
• Main Authors: Dai, Yuhao, Yu, Jimin, Ren, Haojia, Ji, Xuan
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2022
• Subjects: Oceanography; Hydrology; Water Resources; Southern Ocean
• Online Access: https://lup.lub.lu.se/record/f7e42bdf-cc0e-405f-b7f5-f029eab92f75; https://doi.org/10.1038/s41467-022-32895-9

The Subantarctic Southern Ocean has long been thought to be an importantcontributor to increases in atmospheric carbon dioxide partial pressure(pCO2) during glacial-interglacial transitions. Extensive studies suggest that aweakened biological pump, a process associated with nutrient utilizationefficiency, drove up surface-water pCO2in this region during deglaciations. Bycontrast, regional influences of the solubility pump, a process mainly linked totemperature variations, have been largely overlooked. Here, we evaluaterelative roles of the biological and solubility pumps in determining surface-water pCO2variabilities in the Subantarctic Southern Ocean during the lastdeglaciation, based on paired reconstructions of surface-water pCO2,tem-perature, and nutrient utilization efficiency. We show that compared to thebiological pump, the solubility pumpimposed a strong impact on deglacialSubantarctic surface-water pCO2variabilities. Ourfindings therefore reveal apreviously underappreciated role of the solubility pump in modulatingdeglacial Subantarctic CO2release and possibly past atmospheric pCO2fluctuations.