Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model

Steinacher, Marco; Joos, Fortunat; Frölicher, Thomas; Plattner, Gian-Kasper; Doney, S. C. (2009). Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle-climate model. Biogeosciences, 6(4), pp. 515-533. Göttingen: Copernicus Publications 10.5194/bg-6-515-2009

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Ocean acidification from the uptake of anthropogenic carbon is simulated for the industrial period and IPCC SRES emission scenarios A2 and B1 with a global coupled carbon cycle-climate model. Earlier studies identified seawater saturation state with respect to aragonite, a mineral phase of calcium carbonate, as a key variable governing impacts on corals and other shell-forming organisms. Globally in the A2 scenario, water saturated by more than 300%, considered suitable for coral growth, vanishes by 2070 AD (CO2≈630 ppm), and the ocean volume fraction occupied by saturated water decreases from 42% to 25% over this century. The largest simulated pH changes worldwide occur in Arctic surface waters, where hydrogen ion concentration increases by up to 185% (ΔpH=−0.45). Projected climate change amplifies the decrease in Arctic surface mean saturation and pH by more than 20%, mainly due to freshening and increased carbon uptake in response to sea ice retreat. Modeled saturation compares well with observation-based estimates along an Arctic transect and simulated changes have been corrected for remaining model-data differences in this region. Aragonite undersaturation in Arctic surface waters is projected to occur locally within a decade and to become more widespread as atmospheric CO2 continues to grow. The results imply that surface waters in the Arctic Ocean will become corrosive to aragonite, with potentially large implications for the marine ecosystem, if anthropogenic carbon emissions are not reduced and atmospheric CO2 not kept below 450 ppm.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics
08 Faculty of Science > Physics Institute

UniBE Contributor:

Steinacher, Marco; Joos, Fortunat; Frölicher, Thomas and Plattner, Gian-Kasper

Subjects:

500 Science > 530 Physics

ISSN:

1726-4170

Publisher:

Copernicus Publications

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 15:23

Last Modified:

12 Dec 2014 18:57

Publisher DOI:

10.5194/bg-6-515-2009

Web of Science ID:

000265743200002

Additional Information:

Kollaboration. Es sind nur Berner Autoren namentlich erwähnt.

BORIS DOI:

10.7892/boris.37497

URI:

https://boris.unibe.ch/id/eprint/37497 (FactScience: 208758)

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