During the end of the last ice age, vast quantities of CO2, previously sequestered deep within the ocean, surged to the Southern Ocean’s surface and were released into the atmosphere, significantly contributing to global warming. However, it was theorized that some of this stored oceanic carbon might have been swept up and transported directly northward to the eastern equatorial Pacific upwelling region by Antarctic Intermediate Water (AAIW) and Subantarctic Modal Water (SAMW). These water masses can be conceptualized as an “ocean tunnel” connecting the Southern Ocean to equatorial oceanic regions.
“Until now, the precise role of this oceanic ‘tunnel’ in CO2 transport during the last deglaciation remained unclear, largely due to a lack of crucial evidence regarding the source of these intermediate water masses in the southeast Pacific Ocean,” the article states.
Dr. Cyrus Karas and his colleagues have successfully filled this knowledge gap, comprehensively reconstructing the deglacial evolution of Antarctic Intermediate Water (AAIW) and Subantarctic Modal Water (SAMW) near their formation zone in the Southeast Pacific Ocean, off the coast of Chile. “People often overlook the critical role the ocean plays in current climate change,” he stated.
Key Discovery for Geosciences and Climate Change
“This study marks the first comprehensive demonstration of the substantial deglacial transport of CO2-rich water from the Southern Ocean into the Antarctic Intermediate Water (AAIW) and Subantarctic Modal Water (SAMW), and subsequently to the eastern Pacific’s equatorial upwelling. There, it likely contributed to CO2 degassing, potentially even driving the global increase in atmospheric CO2 during that period,” explained the academic from the Department of Geospatial and Environmental Engineering.
This research was highly esteemed by the editors of the prestigious journal Nature Communications, which holds an impact factor of 16.1 and is ranked as the eighth leading global journal in its field (out of 135). The comprehensive preparation of the manuscript, including extensive writing and the intricate analysis of seafloor samples using sophisticated equipment, was a demanding process. “This entire endeavor was facilitated by invaluable international collaboration with the German Research Institute (Helmholtz Centre for Ocean Research, GEOMAR),” he stated. He added, “The manuscript’s path to publication included multiple rounds of rigorous peer review, a process in which international specialists critically evaluate the work and propose improvements.”
This publication is a direct outcome of the Fondecyt Regular project led by Dr. Karas, marking a significant achievement for the project and current research in geosciences and climate change, encompassing both historical and contemporary contexts. “Publishing in a journal as prestigious as Nature Communications is a major accomplishment for the Department of Geospatial and Environmental Engineering and greatly enhances the visibility of our research,” he explained.
In his closing remarks, Dr. Karas encouraged his peers not to abandon efforts to publish in prestigious journals. “Certainly, the path to publication can be arduous, and the majority of research may not find a home in these top-tier outlets. Nonetheless, the pursuit of scientific inquiry remains vital, despite occasional setbacks,” he affirmed.
The article is available for reading at: https://rdcu.be/epCSr