Abstract
The concentration of atmospheric CO2 increased rapidly during the last deglaciation due to CO2 outgassing from oceans. However, records of deglacial surface seawater pCO2-sw are sparse, hindering our understanding of the process and mechanism of air-sea CO2 exchange and its influence on glacial-interglacial climate change. Here we reconstructed surface seawater pCO2-sw for the last deglacial period using carbon isotope composition (δ13C) of giant diatom (Ethmodiscus rex) frustules from deep-sea sedimentary core collected in the Philippine Sea, western Pacific. Results showed that air-sea CO2 was fluctuating in the western Pacific during the last deglaciation. The gradients of air-sea CO2 are dominated by monsoon and biological productivity. The enhanced East Asian winter Monsoon and shallow thermocline during late Heinrich Stadial 1 maintained equilibrium in the air-sea CO2 exchange balance. During the Bølling period, enhanced East Asian Summer Monsoon has been observed to accelerate the dissolution of eolian-dust and promoted the growth of Ethmodiscus rex, which has been linked to increased primary productivity and, consequently, the uptake of atmospheric CO2 in the western Pacific. During the Allerød period, continued enhancement of EASM allowed the Philippine Sea to act as a weak CO2 source releasing CO2 to the atmosphere. During the Younger Dryas period, as the EASM weaken and the EAWM strengthen, ΔpCO2(sw-atm) decreased. Our findings highlight the tropical ocean’s role in deglacial air-sea CO2 exchange and provide insights into the monsoonal and biological drivers of the processes.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
