%0 Journal Article
%@nexthigherunit 8JMKD3MGPCW/3F35TRS
%@nexthigherunit 8JMKD3MGPCW/46KUATE
%@archivingpolicy denypublisher denyfinaldraft24
%3 piacsek_changes.pdf
%4 sid.inpe.br/mtc-m21c/2021/02.10.11.38
%8 Jan.
%9 journal article
%@issn 0031-0182
%A Piacsek, Patrícia,
%A Behling, Hermann,
%A Gu, Fang,
%A Venancio, Igor Martins,
%A Lessa, Douglas V. O.,
%A Belem, André,
%A Albuquerque, Ana Luiza S.,
%@secondarytype PRE PI
%B Palaeogeography, Palaeoclimatology, Palaeoecology
%D 2021
%K Dinoflagellate, Glacial-Interglacial, Intertropical Convergence Zone, Heinrich Stadials.
%P e109952
%@secondarymark A1_INTERDISCIPLINAR A1_GEOGRAFIA A1_ENGENHARIAS_III A1_CIÊNCIAS_AMBIENTAIS A1_BIODIVERSIDADE A2_SAÚDE_COLETIVA A2_GEOCIÊNCIAS A2_CIÊNCIAS_AGRÁRIAS_I B1_QUÍMICA B1_ENGENHARIAS_IV B1_CIÊNCIAS_BIOLÓGICAS_I B2_ASTRONOMIA_/_FÍSICA C_FILOSOFIA/TEOLOGIA:subcomissão_FILOSOFIA
%T Changes in sea surface hydrography and productivity in the western equatorial Atlantic since the last interglacial
%V 562
%X Scientific projections point to the increase of greenhouse gas levels in the atmosphere will turn the oceans warmer and, consequently, the upper layer of the thermohaline circulation will get thicker, restricting the productivity areas. Oligotrophic conditions will tend to prevail, and expanding the range of proxy data in oligotrophic oceans, across different climate scenarios, has the potential to improve predictions of climate models about how primary productivity will respond. Still, the variability of past primary production in the equatorial Atlantic remains elusive. We used organic-walled dinoflagellate cysts (dinocysts) assemblages to reconstruct changes in the sea surface hydrography and productivity in the western equatorial Atlantic over the last similar to 130 kyr. Four dinocysts assemblages were defined: open ocean, river outflow, neritic and nutricline assemblages. Multiple proxies were used to support the environmental changes evidenced by the observed variations in the dinocyst assemblages, such as the X-ray fluorescence (XRF) Ti/Ca ratio, and planktonic foraminifera abundances. We observed glacial-interglacial as well as the millennial-scale changes in the dinocyst assemblages. A clear glacial-interglacial pattern was marked by more autotrophs dinocysts over the interglacials and the prevalence of heterotrophs dinocysts during the glacial period. We pointed out the interchange of autotrophs assemblages (nutricline and open ocean) over the interglacials intervals, denoting divergences in nutrient availability. During the last glacial period, precipitation events occurred in northeastern Brazil due to southward displacements of the Intertropical Convergence Zone (ITCZ). The increase of precipitation boosted the freshwater input to the adjacent ocean, and the dinocyst assemblages oscillated in response to such freshwater/salinity changes. Over the glacial period, dinocysts with different nutritional requirements (autotrophs and heterotrophs) varied following the ITCZ displacements. Thus, in this study, we showed the influence of ocean-atmospheric processes on the ocean and investigated the productivity in an oligotrophic region over distinct past climatic backgrounds.
%@area MET
%@electronicmailaddress Piacsekpatricia@gmail.com
%@electronicmailaddress
%@electronicmailaddress
%@electronicmailaddress igor.venancio@inpe.br
%@documentstage not transferred
%@group
%@group
%@group
%@group MET-MET-DIPGR-INPE-MCTI-GOV-BR
%@dissemination WEBSCI; PORTALCAPES; AGU; MGA; COMPENDEX.
%@usergroup simone
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation University of Goettingen
%@affiliation University of Goettingen
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation Universidade Federal Fluminense (UFF)
%@affiliation Universidade Federal Fluminense (UFF)
%@versiontype publisher
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@doi 10.1016/j.palaeo.2020.109952
%2 sid.inpe.br/mtc-m21c/2021/02.10.11.38.42