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dc.contributor.authorJensen, Mari Fjalstad
dc.contributor.authorNilsson, Johan
dc.contributor.authorNisancioglu, Kerim Hestnes
dc.description.abstractChanges in the sea ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard–Oeschger events during the last glacial. In this study, we develop a simple conceptual model to examine how interactions between sea ice and oceanic heat and freshwater transports affect the stability of an upper-ocean halocline in a semi-enclosed basin. The model represents a sea ice covered and salinity stratified Nordic Seas, and consists of a sea ice component and a two-layer ocean. The sea ice thickness depends on the atmospheric energy fluxes as well as the ocean heat flux. We introduce a thickness-dependent sea ice export. Whether sea ice stabilizes or destabilizes against a freshwater perturbation is shown to depend on the representation of the diapycnal flow. In a system where the diapycnal flow increases with density differences, the sea ice acts as a positive feedback on a freshwater perturbation. If the diapycnal flow decreases with density differences, the sea ice acts as a negative feedback. However, both representations lead to a circulation that breaks down when the freshwater input at the surface is small. As a consequence, we get rapid changes in sea ice. In addition to low freshwater forcing, increasing deep-ocean temperatures promote instability and the disappearance of sea ice. Generally, the unstable state is reached before the vertical density difference disappears, and the temperature of the deep ocean do not need to increase as much as previously thought to provoke abrupt changes in sea ice.en_US
dc.relation.ispartof<a href="" target="_blank">Abrupt changes in sea ice and dynamics of Dansgaard-Oeschger events</a>en_US
dc.rightsAttribution CC BYeng
dc.subjectSea ice feedbackseng
dc.subjectHalocline dynamicseng
dc.subjectSalinity-dominated ocean circulationeng
dc.subjectConceptual modeleng
dc.subjectDansgaard–Oeschger eventseng
dc.titleThe interaction between sea ice and salinity-dominated ocean circulation: implications for halocline stability and rapid changes of sea ice coveren_US
dc.typePeer reviewed
dc.typeJournal article
dc.rights.holderCopyright 2016 The Author(s)en_US
dc.source.journalClimate Dynamics

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Attribution CC BY
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