Marine Science Faculty Publications

Co2 Cycling in the Coastal Ocean. Ii. Seasonal Organic Loading of the Arctic Ocean from Source Waters in the Bering Sea

Document Type

Article

Publication Date

1996

Digital Object Identifier (DOI)

https://doi.org/10.1016/0278-4343(96)00021-0

Abstract

A Lagrangian model of water parcel transit along at 2850-km trajectory from the 80-m isobath of the southeastern Bering Sea to the same depth of the northwestern Chukchi Sea replicates the major seasonal features of nitrogen and carbon cycling on these shelves. Spring-summer extraction of nitrate from the Bering and Chukchi water columns and of CO2 from the atmosphere is followed by fall-winter storage of ammonium and DOC near the shelf-break of the Canadian Basin. Here, the memory of a simulated seasonal range in water parcel contents of 0.2-13.0 μg-at NO3 l-1, 2056-2125 μg at ΣCO2 l-1, 0.3-3.3 μg-at NH4 l-1, and 67-134 μg-at total marine DOC l-1, exiting the Chukchi Sea, is evidently maintained in the halocline of the adjacent Canadian Basin at depths of ~75 m during summer and ~125 m during winter. Based on these properties of imported water parcels, estimated rates of nitrification, DOC oxidation, and ΣCO2 evolution in the Canadian Basin suggest (1) a residence of ~10 y for shelf waters of Pacific origin in the halocline, (2) production of POC within the overlying ice-covered slope waters may indeed be 10-fold larger than first estimates made in the deeper Basin during the 1950s, (3) ~81% of all of the DOC within Bering Strait is of marine origin from prior production cycles in the SBS, and (4) over 50% of the colon signal seen by satellite above these waters is of DOC origin, rather than from phytoplankton pigments.

Citation / Publisher Attribution

Continental Shelf Research, v. 17, issue 1, p. 1-36

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