%0 Journal Article
%@nexthigherunit 8JMKD3MGPCW/3F35TRS
%@nexthigherunit 8JMKD3MGPCW/46KUATE
%3 nascimento_tropical.pdf
%4 sid.inpe.br/mtc-m21d/2021/06.21.13.24
%8 Aug.
%9 journal article
%@issn 0012-821X
%A Nascimento, Rodrigo A.,
%A Venâncio, Igor Martins,
%A Chiessi, C. M.,
%A Ballalai, J. M.,
%A Kuhnert, H.,
%A Johnstone, H.,
%A Santos, T. P.,
%A Prange, M.,
%A Govin, A.,
%A Crivellari, S.,
%A Mulitza, S.,
%A Albuquerque, A. L. S.,
%@secondarytype PRE PI
%B Earth and Planetary Science Letters
%D 2021
%@archivingpolicy denypublisher denyfinaldraft24
%K ITCZ, precession, South Atlantic Subtropical Gyre, western tropical Atlantic stratification.
%P e117030
%@secondarymark A1_QUÍMICA A1_INTERDISCIPLINAR A1_GEOGRAFIA A1_GEOCIÊNCIAS A1_ANTROPOLOGIA_/_ARQUEOLOGIA A2_ENGENHARIAS_II A2_CIÊNCIAS_BIOLÓGICAS_III A2_BIOTECNOLOGIA B2_SOCIOLOGIA
%T Tropical Atlantic stratification response to late Quaternary precessional forcing
%V 568
%X 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.
%@area MET
%@electronicmailaddress rodrigoan@id.uff.br
%@documentstage not transferred
%@group
%@group MET-MET-DIPGR-INPE-MCTI-GOV-BR
%@dissemination WEBSCI; PORTALCAPES; SCOPUS.
%@usergroup simone
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Universidade de São Paulo (USP)
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation University of Bremen
%@affiliation University of Bremen
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation University of Bremen
%@affiliation Université Paris Saclay
%@affiliation Universidade de São Paulo (USP)
%@affiliation University of Bremen
%@affiliation Universidade Federal Fluminense (UFF)
%@versiontype publisher
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@doi 10.1016/j.epsl.2021.117030
%2 sid.inpe.br/mtc-m21d/2021/06.21.13.24.06