Publikationsdatum:
2022-05-27
Beschreibung:
Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(8), (2021):
e2021JC017510, https://doi.org/10.1029/2021JC017510.
Beschreibung:
The air-sea exchange of oxygen (O2) is driven by changes in solubility, biological activity, and circulation. The total air-sea exchange of O2 has been shown to be closely related to the air-sea exchange of heat on seasonal timescales, with the ratio of the seasonal flux of O2 to heat varying with latitude, being higher in the extratropics and lower in the subtropics. This O2/heat ratio is both a fundamental biogeochemical property of air-sea exchange and a convenient metric for testing earth system models. Current estimates of the O2/heat flux ratio rely on sparse observations of dissolved O2, leaving it fairly unconstrained. From a model ensemble we show that the ratio of the seasonal amplitude of two atmospheric tracers, atmospheric potential oxygen (APO) and the argon-to-nitrogen ratio (Ar/O2), exhibits a close relationship to the O2/heat ratio of the extratropics (40–70°). The amplitude ratio, A APO/A ArN2, is relatively constant within the extratropics of each hemisphere due to the zonal mixing of the atmosphere. A APO/A ArN2 is not sensitive to atmospheric transport, as most of the observed spatial variability in the seasonal amplitude of δAPO is compensated by similar variations in δ(Ar/N2). From the relationship between O2/heat and A APO/A ArN2 in the model ensemble, we determine that the atmospheric observations suggest hemispherically distinct O2/heat flux ratios of 3.3 ± 0.3 and 4.7 ± 0.8 nmol J-1 between 40 and 70° in the Northern and Southern Hemispheres respectively, providing a useful constraint for O2 and heat air-sea fluxes in earth system models and observation-based data products.
Beschreibung:
The recent atmospheric measurements of the Scripps program have been supported via funding from the NSF and the National Oceanographic and Atmospheric Administration (NOAA) under grants 1304270 and OAR-CIPO-2015-2004269. M. Manizza and R. F. Keeling thank NSF for financial support via the OCE-1130976 grant. M. Manizza thanks additional financial support from NSF via the ARRA OCE-0850350 grant. S. C. Doney acknowledges support from NSF PLR-1440435. Keith Rodgers acknowledges support from IBS-R028-D1. Gael Forget and the ECCO group kindly provided the ECCOv4 heat fluxes.
Beschreibung:
2022-01-22
Repository-Name:
Woods Hole Open Access Server
Materialart:
Article
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