Sudden emergence of a shallow aragonite saturation horizon in the Southern Ocean

Gabriela Negrete-García, Nicole S. Lovenduski (), Claudine Hauri, Kristen M. Krumhardt and Siv K. Lauvset
Additional contact information
Gabriela Negrete-García: University of Colorado Boulder
Nicole S. Lovenduski: University of Colorado Boulder
Claudine Hauri: University of Alaska Fairbanks
Kristen M. Krumhardt: University of Colorado Boulder
Siv K. Lauvset: Bjerknes Centre for Climate Research

Nature Climate Change, 2019, vol. 9, issue 4, 313-317

Abstract: Abstract Models project that with current CO2 emission rates, the Southern Ocean surface will be undersaturated with respect to aragonite by the end of this century1–4. This will result in widespread impacts on biogeochemistry and ocean ecosystems5–7, particularly the health of aragonitic organisms, such as pteropods7, which can dominate polar surface water communities6. Here, we quantify the depth of the present-day Southern Ocean aragonite saturation horizon using hydrographic and ocean carbon chemistry observations, and use a large ensemble of simulations from the Community Earth System Model (CESM)8,9 to track its evolution. A new, shallow aragonite saturation horizon emerges in many Southern Ocean locations between now and the end of the century. While all ensemble members capture the emergence, internal climate variability may affect the year of emergence; thus, its detection may have been overlooked by ensemble average analysis in the past. The emergence of the new horizon is driven by the slow accumulation of anthropogenic CO2 in the Southern Ocean thermocline, where the carbonate ion concentration exhibits a local minimum and approaches undersaturation. The new horizon is also apparent under an emission-stabilizing scenario indicating an inevitable, sudden decrease in the volume of suitable habitat for aragonitic organisms.

Date: 2019
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41558-019-0418-8 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcli:v:9:y:2019:i:4:d:10.1038_s41558-019-0418-8

Ordering information: This journal article can be ordered from
https://www.nature.com/nclimate/

DOI: 10.1038/s41558-019-0418-8

Access Statistics for this article

Nature Climate Change is currently edited by Bronwyn Wake

More articles in Nature Climate Change from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().