气候变化领域集成服务门户(CCPortal): Tropical Atlantic stratification response to late Quaternary precessional forcing

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DOI	10.1016/j.epsl.2021.117030
	Tropical Atlantic stratification response to late Quaternary precessional forcing
	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.
发表日期	2021
ISSN	0012821X
卷号	568
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.
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
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203236
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
推荐引用方式 GB/T 7714	Nascimento R.A.,Venancio I.M.,Chiessi C.M.,et al. Tropical Atlantic stratification response to late Quaternary precessional forcing[J],2021,568.
APA	Nascimento R.A..,Venancio I.M..,Chiessi C.M..,Ballalai J.M..,Kuhnert H..,...&Albuquerque A.L.S..(2021).Tropical Atlantic stratification response to late Quaternary precessional forcing.Earth and Planetary Science Letters,568.
MLA	Nascimento R.A.,et al."Tropical Atlantic stratification response to late Quaternary precessional forcing".Earth and Planetary Science Letters 568(2021).