Title: Isopycnal mixing by mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake

Abstract

Abstract Anthropogenic carbon dioxide uptake varies across Earth System Models for reasons that have remained obscure. When varied within a single model, the lateral eddy mixing coefficient A _Redi produces a range of uptake similar to the modeled range. The highest uptake, resulting from a simulation with a constant A _Redi of 2400 m ² /s, simulates 15% more historical carbon uptake than a model with A _Redi  = 400 m ² /s. A sudden doubling in carbon dioxide produces a 21% range in carbon uptake across the models. Two spatially dependent representations of A _Redi produce uptake that lies in the middle of the range of constant values despite predicting very large values in the subtropical gyres. One‐dimensional diffusive models of the type used for integrated assessments can be fit to the simulations, with A _Redi accounting for a substantial fraction of the effective vertical diffusion. Such models, however, mask significant regional changes in stratification and biological carbon storage.

Authors:

Gnanadesikan, Anand ^[1]; Pradal, Marie‐Aude ^[1]; Abernathey, Ryan ^[2]

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+ Show Author Affiliations

1. Department of Earth and Planetary Sciences Johns Hopkins University Baltimore Maryland USA
2. Department of Earth and Environmental Sciences Columbia University New York New York USA

Publication Date:

Tue Jun 02 00:00:00 EDT 2015

Sponsoring Org.:

USDOE

OSTI Identifier:

1402373

Grant/Contract Number:  

SC0007066

Resource Type:

Publisher's Accepted Manuscript

Journal Name:

Geophysical Research Letters

Additional Journal Information:

Journal Name: Geophysical Research Letters Journal Volume: 42 Journal Issue: 11; Journal ID: ISSN 0094-8276

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English