DOI: 10.1016/j.quascirev.2013.06.016
Scopus记录号: 2-s2.0-84880627824
论文题名: Evolution of subpolar North Atlantic surface circulation since the early Holocene inferred from planktic foraminifera faunal and stable isotope records
作者: Staines-Urías F. ; Kuijpers A. ; Korte C.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2013
卷: 76 起始页码: 66
结束页码: 81
语种: 英语
英文关键词: Eastern North Atlantic
; North Atlantic Oscillation
; Paleoceanography
; Planktic foraminifera
; Subpolar Gyre
Scopus关键词: North Atlantic
; North Atlantic oscillations
; Paleoceanography
; Planktic foraminifera
; Subpolar gyres
; Atmospheric pressure
; Isotopes
; Oceanography
; Surface waters
; atmospheric forcing
; gyre
; Holocene
; hydrography
; isotopic analysis
; North Atlantic Oscillation
; oceanic circulation
; oxygen isotope
; paleoceanography
; planktonic foraminifera
; salinity
; stable isotope
; surface flux
; water column
; water mass
; Atlantic Ocean
; Atlantic Ocean (North)
; Faroe Islands
英文摘要: Past changes in the surface flow regime of two main eastern North Atlantic warm water pathways towardthe Nordic seas were reconstructed based on faunal analyses in combination with carbon and oxygen stable isotope measurements in planktic foraminifera. The investigated sites, in the surroundings of the Faroe Islands, are located in the transitional area where surface waters of subpolar and subtropical origin mix before entering the Arctic Mediterranean. In these areas, large-amplitude millennial variability in the characteristics of the upper-water column appears modulated by changes in the intensity of the Subpolar Gyre circulation. From 7.8 to 6ka BP, faunal records indicate a deep mixed-layer which, in conjunction with lighter δ18O values, suggest that the inflowing Atlantic waters were dominated by a relatively cooler and fresher water mass, reflecting a strengthening of the Subpolar Gyre under conditions of enhanced positive NAO-like forcing and reduced meltwater input. A shift in the hydrographic conditions occurred during the Mid-Holocene (centered at 5ka BP). At this time, increasing upper water column stratification and the incipient differentiation of the stable isotopic signal of the Iceland-Faroe and Faroe-Shetland surface water masses, suggest increasing influx of warmer, more saline surface waters from the Subtropical Gyre, as Subpolar Gyre circulation weakened. The mid-Holocene decline in Subpolar Gyre strength is presumably related to a shift towarda low state of the NAO-like forcing associated with decreased solar irradiance. Later in the Holocene, from 4ka BP to present, the increased frequency and reduced amplitude of the surface hydrographic changes reflect corresponding fluctuations in Subpolar Gyre circulation. These high frequency oscillations in Subpolar Gyre strength suggest increased surface circulation sensitivity to moderate freshwater fluxes to the Labrador-Irminger Sea basin, highlighting the importance of the salinity balance in modulating Subpolar Gyre dynamics, particularly under conditions of low NAO atmospheric forcing. © 2013 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60542
Appears in Collections: 过去全球变化的重建
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作者单位: Geological Survey of Denmark and Greenland, Marine Geology and Glaciology Department, Øster Voldgade 10, 1350 K Copenhagen, Denmark; University of Copenhagen, Department of Geosciences and Natural Resource Management, Øster Voldgade 10, 1350 K Copenhagen, Denmark
Recommended Citation:
Staines-Urías F.,Kuijpers A.,Korte C.. Evolution of subpolar North Atlantic surface circulation since the early Holocene inferred from planktic foraminifera faunal and stable isotope records[J]. Quaternary Science Reviews,2013-01-01,76