DOI: 10.1007/s00382-012-1479-9
Scopus记录号: 2-s2.0-84881023542
论文题名: Decadal fingerprints of freshwater discharge around Greenland in a multi-model ensemble
作者: Swingedouw D. ; Rodehacke C.B. ; Behrens E. ; Menary M. ; Olsen S.M. ; Gao Y. ; Mikolajewicz U. ; Mignot J. ; Biastoch A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2013
卷: 41, 期: 2017-03-04 起始页码: 695
结束页码: 720
语种: 英语
英文关键词: AMOC
; Greenland ice sheet melting
; North Atlantic
; Ocean-atmosphere interactions
; Oceanic dynamics
; Oceanic gyre
; Sea-level rise
; Thermohaline circulation
英文摘要: The recent increase in the rate of the Greenland ice sheet melting has raised with urgency the question of the impact of such a melting on the climate. As former model projections, based on a coarse representation of the melting, show very different sensitivity to this melting, it seems necessary to consider a multi-model ensemble to tackle this question. Here we use five coupled climate models and one ocean-only model to evaluate the impact of 0.1 Sv (1 Sv = 106 m3/s) of freshwater equally distributed around the coast of Greenland during the historical era 1965-2004. The ocean-only model helps to discriminate between oceanic and coupled responses. In this idealized framework, we find similar fingerprints in the fourth decade of hosing among the models, with a general weakening of the Atlantic Meridional Overturning Circulation (AMOC). Initially, the additional freshwater spreads along the main currents of the subpolar gyre. Part of the anomaly crosses the Atlantic eastward and enters into the Canary Current constituting a freshwater leakage tapping the subpolar gyre system. As a consequence, we show that the AMOC weakening is smaller if the leakage is larger. We argue that the magnitude of the freshwater leakage is related to the asymmetry between the subpolar-subtropical gyres in the control simulations, which may ultimately be a primary cause for the diversity of AMOC responses to the hosing in the multi-model ensemble. Another important fingerprint concerns a warming in the Nordic Seas in response to the re-emergence of Atlantic subsurface waters capped by the freshwater in the subpolar gyre. This subsurface heat anomaly reaches the Arctic where it emerges and induces a positive upper ocean salinity anomaly by introducing more Atlantic waters. We found similar climatic impacts in all the coupled ocean-atmosphere models with an atmospheric cooling of the North Atlantic except in the region around the Nordic Seas and a slight warming south of the equator in the Atlantic. This meridional gradient of temperature is associated with a southward shift of the tropical rains. The free surface models also show similar sea-level fingerprints notably with a comma-shape of high sea-level rise following the Canary Current. © 2012 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54828
Appears in Collections: 过去全球变化的重建
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作者单位: LSCE/IPSL, Gif-sur-Yvette, France; Max-Planck-Institut für Meteorologie, Hamburg, Germany; GEOMAR/Helmhotz Centre for Ocean Research, Kiel, Germany; Met Office Hadley Centre, Exeter, United Kingdom; DMI, Copenhagen, Denmark; NERSC, Bergen, Norway; LOCEAN/IPSL, Paris, France
Recommended Citation:
Swingedouw D.,Rodehacke C.B.,Behrens E.,et al. Decadal fingerprints of freshwater discharge around Greenland in a multi-model ensemble[J]. Climate Dynamics,2013-01-01,41(2017-03-04)