Fingerprint of Climate Change on Southern Ocean Carbon Storage
| Type | Article | ||||||||
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| Date | 2023-04 | ||||||||
| Language | English | ||||||||
| Author(s) | Wright R. M. 1, Le Quéré C.1, Mayot N.1, Olsen A.2, 3, Bakker D. C. E.1 |
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| Affiliation(s) | 1 : Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences University of East Anglia Norwich ,UK 2 : Geophysical Institute University of Bergen Bergen, Norway 3 : Bjerknes Centre for Climate Research Bergen ,Norway |
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| Source | Global Biogeochemical Cycles (0886-6236) (American Geophysical Union (AGU)), 2023-04 , Vol. 37 , N. 4 , P. e2022GB007596 (12p.) | ||||||||
| DOI | 10.1029/2022GB007596 | ||||||||
| Note | This article also appears in: Southern Ocean and Climate: Biogeochemical and Physical Fluxes and Processes | ||||||||
| Keyword(s) | dissolved inorganic carbon, Southern Ocean, climate variability, carbon storage | ||||||||
| Abstract | The Southern Ocean plays a critical role in the uptake, transport, and storage of carbon by the global oceans. It is the ocean's largest sink of CO2, yet it is also among the regions with the lowest storage of anthropogenic carbon. This behavior results from a unique combination of high winds driving the upwelling of deep waters and the subduction and northward transport of surface carbon. Here we isolate the direct effect of increasing anthropogenic CO2 in the atmosphere from the indirect effect of climate variability and climate change on the reorganization of carbon in the Southern Ocean interior using a combination of modeling and observations. We show that the effect of climate variability and climate change on the storage of carbon in the Southern Ocean is nearly as large as the effect of anthropogenic CO2 during the period 1998–2018 compared with the climatology around the year 1995. We identify a distinct climate fingerprint in dissolved inorganic carbon (DIC), with elevated DIC concentration in the ocean at 300–600 m that reinforces the anthropogenic CO2 signal, and reduced DIC concentration in the ocean around 2,000 m that offsets the anthropogenic CO2 signal. The fingerprint is strongest at lower latitudes (30°–55°S). This fingerprint could serve to monitor the highly uncertain evolution of carbon within this critical ocean basin, and better identify its drivers. Key Points The effect of decadal climate variability on dissolved inorganic carbon (DIC) in the Southern Ocean is nearly as large as that of atmospheric CO2 Climatic drivers cause a distinct fingerprint on the change in DIC concentration in the Southern Ocean interior This fingerprint could serve to detect future trends in Southern Ocean carbon storage |
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