Isopycnal mixing by mesoscale eddies significantly impacts oceanic anthropogenic carbon uptake

Journal Article · Tue Jun 02 00:00:00 EDT 2015 · Geophysical Research Letters

DOI:https://doi.org/10.1002/2015GL064100· OSTI ID:1402373

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

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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

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.

• Sponsoring Organization: USDOE
• Grant/Contract Number: SC0007066
• OSTI ID: 1402373
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Vol. 42 Journal Issue: 11; ISSN 0094-8276
• Publisher: American Geophysical Union (AGU)
• Country of Publication: United States
• Language: English