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A continental shelf pump for CO2 on the Adelie land coast, East Antarctica

Citation

Arroyo, MC and Shadwick, EH and Tilbrook, B and Rintoul, SR and Kusahara, K, A continental shelf pump for CO2 on the Adelie land coast, East Antarctica, Journal of Geophysical Research: Oceans, 125, (10) Article e2020JC016302. ISSN 2169-9275 (2020) [Refereed Article]


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DOI: doi:10.1029/2020JC016302

Abstract

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. For this purpose, observations of total dissolved inorganic carbon (TCO2) from two summer hydrographic surveys in 2015 and 2017 were paired with DSW volume transport estimates derived from a coupled ocean-sea ice-ice shelf model to examine the fate of inorganic carbon in DSW from Adélie Land. Transports indicate a net outflow of 227 ± 115 Tg C yr−1 with DSW in the postglacial 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 DSW 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 time scale of centuries.

Item Details

Item Type:Refereed Article
Keywords:carbon export, dense shelf water, Mertz Polynya
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Chemical oceanography
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Antarctic and Southern Ocean oceanic processes
UTAS Author:Shadwick, EH (Dr Elizabeth Shadwick)
UTAS Author:Tilbrook, B (Dr Bronte Tilbrook)
UTAS Author:Rintoul, SR (Dr Steve Rintoul)
ID Code:151322
Year Published:2020
Deposited By:Australian Antarctic Program Partnership
Deposited On:2022-07-27
Last Modified:2022-07-27
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