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Dissolved organic carbon in the Ross Sea: Deep enrichment and export
Author(s) -
Bercovici Sarah K.,
Huber Bruce A.,
DeJong Hans B.,
Dunbar Robert B.,
Hansell Dennis A.
Publication year - 2017
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.1002/lno.10592
Subject(s) - dissolved organic carbon , oceanography , antarctic bottom water , continental shelf , carbon cycle , deep sea , total organic carbon , water mass , environmental science , geology , seawater , carbon fibers , bottom water , environmental chemistry , chemistry , ecosystem , ecology , materials science , composite number , composite material , biology
Antarctica's continental shelves generate the densest waters in the world and are responsible for the formation of Antarctic Bottom Water (AABW), a water mass with the potential to sequester carbon in the deep ocean for millennia. One such form of marine carbon is dissolved organic carbon (DOC), the ocean's largest standing stock of reduced carbon. In this study, we quantify DOC enrichment in dense shelf waters (DSW) in the Ross Sea and assess the potential for DOC to be sequestered from Antarctic shelves into AABW. We find that Ross Sea DSW is enriched in DOC by ∼7 μ mol kg −1 relative to the incoming source waters (initial conditions), which is primarily caused by vertical mixing. The total DOC excess in DSW suggests that 4.0 ± 0.6 Tg DOC yr −1 is exported off the shelf. However, this exported fraction does not appear to persist in newly formed AABW and is likely remineralized, sequestering this carbon as TCO 2 in the deep ocean.