DOI: 10.1016/j.epsl.2021.117030
论文题名: Tropical Atlantic stratification response to late Quaternary precessional forcing
作者: Nascimento R.A. ; Venancio I.M. ; Chiessi C.M. ; Ballalai J.M. ; Kuhnert H. ; Johnstone H. ; Santos T.P. ; Prange M. ; Govin A. ; Crivellari S. ; Mulitza S. ; Albuquerque A.L.S.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 568 语种: 英语
中文关键词: ITCZ
; precession
; South Atlantic Subtropical Gyre
; western tropical Atlantic stratification
英文关键词: Incident solar radiation
; Oceanography
; Orbits
; Stream flow
; ITCZ
; Northern Hemispheres
; Ocean stratification
; Precession
; South atlantic subtropical gyre
; Thermocline temperature
; Tropical atlantic
; Upper ocean
; Western tropical atlantic
; Western tropical atlantic stratification
; Tropics
; atmospheric circulation
; atmospheric forcing
; gyre
; intertropical convergence zone
; meridional circulation
; oceanic circulation
; overturn
; paleoclimate
; Quaternary
; Atlantic Ocean
; Atlantic Ocean (North)
; Foraminifera
; Globigerinoides ruber
; Globorotalia truncatulinoides
英文摘要: The upper ocean circulation in the western tropical Atlantic (WTA) is responsible for the northward cross-equatorial heat transport as part of the Atlantic Meridional Overturning Circulation (AMOC). This cross-equatorial transport is influenced by the thermocline circulation and stratification. Although seasonal thermocline stratification in the WTA is precession-driven, the existence of an orbital pacemaker of changes in the entire WTA upper ocean stratification, which comprises the main thermocline, remains elusive. Here, we present a 300 ka-long record of the WTA upper ocean stratification and main thermocline temperature based on oxygen isotopes (δ18O) and Mg/Ca of planktonic foraminifera. Our Δδ18O record between Globigerinoides ruber and Globorotalia truncatulinoides, representing upper ocean stratification, shows a robust precession pacing, where strong stratification was linked to high summer insolation in the Northern Hemisphere (precession minima). Mg/Ca-based temperatures support that stratification is dominated by changes in thermocline temperature. We present a new mechanism to explain changes in WTA stratification, where during the Northern Hemisphere summer insolation maxima, the Intertropical Convergence Zone shifts northward, developing a negative wind stress curl anomaly in the tropical Atlantic. This, in turn, pulls the main thermocline up and pushes the South Atlantic Subtropical Gyre southwards, increasing the stratification to the north of the gyre. This mechanism is supported by experiments performed with the Community Earth System Model (CESM1.2). Finally, we hypothesize that the precession-driven WTA stratification may affect the cross-equatorial flow into the North Atlantic. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165614
Appears in Collections: 气候变化与战略
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作者单位: Programa de Geociências (Geoquímica), Universidade Federal Fluminense, Niterói, Brazil; Center for Weather Forecasting and Climate Studies (CPTEC), National Institute for Space Research (INPE), Cachoeira Paulista, Brazil; School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil; MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany; Laboratoire des Sciences du Climat et de l'Environnement/Institut Pierre Simon Laplace, CEA-CNRS-UVSQ, Université Paris Saclay, Gif sur Yvette, France
Recommended Citation:
Nascimento R.A.,Venancio I.M.,Chiessi C.M.,et al. Tropical Atlantic stratification response to late Quaternary precessional forcing[J]. Earth and Planetary Science Letters,2021-01-01,568