Quantification of Chaotic Intrinsic Variability of Sea‐Air CO(2) Fluxes at Interannual Timescales

• Published in: Geophysical Research Letters
• Main Authors: Gehlen, M., Berthet, S., Séférian, R., Ethé, Ch., Penduff, T.
• Format: Text
• Language: English
• Published: John Wiley and Sons Inc. 2020
• Subjects: Research Letters; Southern Ocean
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7757255/; http://www.ncbi.nlm.nih.gov/pubmed/33380759; https://doi.org/10.1029/2020GL088304

Chaotic intrinsic variability (CIV) emerges spontaneously from nonlinear ocean dynamics even without any atmospheric variability. Eddy‐permitting numerical simulations suggest that CIV is a significant contributor to the interannual to decadal variability of physical properties. Here we show from an ensemble of global ocean eddy‐permitting simulations that large‐scale interannual CIV propagates from physical properties to sea‐air CO(2) fluxes in areas of high mesoscale eddy activity (e.g., Southern Ocean and western boundary currents). In these regions and at scales larger than 500 km (~5°), CIV contributes significantly to the interannual variability of sea‐air CO(2) fluxes. Between 35°S and 45°S (midlatitude Southern Ocean), CIV amounts to 23.76 TgC yr(−1) or one half of the atmospherically forced variability. Locally, its contribution to the total interannual variance of sea‐air CO(2) fluxes exceeds 76%. Outside eddy‐active regions its contribution to total interannual variability is below 16%.