A Continental Shelf Pump for CO2 on the Adélie Land Coast, East Antarctica

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Arroyo, Mar; Shadwick, Elizabeth ORCID ID icon; Tilbrook, Bronte; Rintoul, Steve; Kusahara, K


2020-10-07


Journal Article


Journal of Geophysical Research-Oceans


125


22


We quantify the transport of inorganic carbon from the continental shelf to the deep ocean in Dense Shelf Water (DSW) from the Mertz and Ninnis Polynyas along the Adélie Land coast in East Antarctica. Observations of total dissolved inorganic carbon (TCO2) from two summer hydrographic surveys in 2015 and 2017 were paired with volume transport estimates derived from a coupled ocean-sea ice-ice shelf model (Kusahara et al. 2017) to examine the fate of inorganic carbon in DSW from Adélie Land. Transports indicate a net outflow of 227 ± 115 Tg C year-1 with DSW in the post-glacial calving configuration of the Mertz Polynya. The greatest outflow of inorganic carbon from the shelf region was delivered through the northern boundary across the Adélie and Mertz Sills, with an additional transport westward from the Mertz Polynya. Inorganic carbon in DSW is derived primarily from inflowing TCO2-rich modified Circumpolar Deep Water; local processes (biological productivity, air-sea exchange of CO2, and the addition of brine during sea ice formation) make much smaller contributions. This study proposes that Dense Shelf Water export serves as a continental shelf pump for CO2 and is a pathway to sequester inorganic carbon from the shallow Antarctic continental shelf to the abyssal ocean, removing CO2 from atmospheric exchange on the timescale of centuries.


American Geophysical Union


Ocean carbon


Climate Change Processes; Chemical Oceanography; Environmental Monitoring; Physical Oceanography


https://doi.org/10.1029/2020JC016302


EP206894


Journal article - Refereed


English


Arroyo, Mar; Shadwick, Elizabeth; Tilbrook, Bronte; Rintoul, Steve; Kusahara, K. A Continental Shelf Pump for CO2 on the Adélie Land Coast, East Antarctica. Journal of Geophysical Research-Oceans. 2020; 125:22. https://doi.org/10.1029/2020JC016302



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