DOI: 10.1007/s00382-016-3027-5
Scopus记录号: 2-s2.0-84959107837
论文题名: The interaction between sea ice and salinity-dominated ocean circulation: implications for halocline stability and rapid changes of sea ice cover
作者: Jensen M.F. ; Nilsson J. ; Nisancioglu K.H.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2016
卷: 47, 期: 2017-09-10 起始页码: 3301
结束页码: 3317
语种: 英语
英文关键词: Conceptual model
; Dansgaard–Oeschger events
; Halocline dynamics
; Salinity-dominated ocean circulation
; Sea ice feedbacks
英文摘要: Changes 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. © 2016, The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53495
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Earth Science, University of Bergen, Bergen, Norway; Bjerknes Centre for Climate Research, Bergen, Norway; Department of Meteorology, Stockholm University, Stockholm, Sweden
Recommended Citation:
Jensen M.F.,Nilsson J.,Nisancioglu K.H.. The interaction between sea ice and salinity-dominated ocean circulation: implications for halocline stability and rapid changes of sea ice cover[J]. Climate Dynamics,2016-01-01,47(2017-09-10)