Precessional cycles in Upper Cretaceous pelagic sediments of the South Atlantic: Long-term patterns from high-frequency climate variations

1999 ◽  
Author(s):  
Timothy D. Herbert ◽  
Jeff Gee ◽  
Steve DiDonna
Keyword(s):  
High Frequency ◽  
Upper Cretaceous ◽  
South Atlantic ◽  
Climate Variations ◽  
The South

scholarly journals Meridional changes in the South Atlantic Subtropical Gyre during Heinrich Stadials

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tainã M. L. Pinho ◽  
Cristiano M. Chiessi ◽  
Rodrigo C. Portilho-Ramos ◽  
Marília C. Campos ◽  
Stefano Crivellari ◽  
...  
Keyword(s):  
Global Climate ◽  
South Atlantic ◽  
Subtropical Gyre ◽  
Climate System ◽  
The South ◽  
Foraminiferal Species ◽  
Ocean Gyres ◽  
Long Term Monitoring ◽  
Term Monitoring

AbstractSubtropical ocean gyres play a key role in modulating the global climate system redistributing energy between low and high latitudes. A poleward displacement of the subtropical gyres has been observed over the last decades, but the lack of long-term monitoring data hinders an in-depth understanding of their dynamics. Paleoceanographic records offer the opportunity to identify meridional changes in the subtropical gyres and investigate their consequences to the climate system. Here we use the abundance of planktonic foraminiferal species Globorotalia truncatulinodes from a sediment core collected at the northernmost boundary of the South Atlantic Subtropical Gyre (SASG) together with a previously published record of the same species from the southernmost boundary of the SASG to reconstruct meridional fluctuations of the SASG over last ca. 70 kyr. Our findings indicate southward displacements of the SASG during Heinrich Stadials (HS) 6-4 and HS1, and a contraction of the SASG during HS3 and HS2. During HS6-4 and HS1, the SASG southward displacements likely boosted the transfer of heat to the Southern Ocean, ultimately strengthening deep-water upwelling and CO2 release to the atmosphere. We hypothesize that the ongoing SASG poleward displacement may further increase oceanic CO2 release.

Cross-Shelf Exchange Associated With the Gulf Stream in the South Atlantic Bight: Direct Observations Using an Autonomous Underwater Glider

2018 ◽  
Vol 52 (3) ◽  
pp. 19-27 ◽  
Author(s):  
Ruoying He ◽  
Austin C. Todd ◽  
Chad Lembke ◽  
Todd Kellison ◽  
Chris Taylor ◽  
...  
Keyword(s):  
Gulf Stream ◽  
Moving Boundary ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
Underwater Glider ◽  
The South ◽  
Underwater Gliders ◽  
Direct Observations ◽  
Autonomous Underwater Glider

AbstractAn autonomous underwater glider was deployed in March 2014 to sample the Gulf Stream and its adjacent shelf waters in the South Atlantic Bight, providing a new look at cross-shelf exchange associated with Gulf Stream dynamics. Observations collected over 4 weeks reveal significant cross-shelf exchange (up to 0.5 Sv) at the shoreward edge of the Gulf Stream, which was 2 orders of magnitude larger than estimates from long-term mean hydrographic conditions. Gulf Stream frontal eddies may have contributed to some of the largest fluxes of heat (0.5°C Sv) and salt (0.03 Sv g/kg) onto the shelf. We estimate that the largest upwelling event during the mission could have brought nitrate concentrations over 20 μM to within 125 m of the surface. This study demonstrates clear capabilities of autonomous underwater gliders for sampling in and near fast moving boundary currents to obtain unique and critical in situ observations effectively.

scholarly journals Data Correction Needed for Long-Term Heat Transport Monitoring

Eos ◽  
2015 ◽  
Vol 96 ◽  
Author(s):  
Eric Betz
Keyword(s):  
Atlantic Ocean ◽  
Heat Transport ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Ocean Heat Transport ◽  
The South ◽  
Data Correction ◽  
Historical Temperature

Scientists assess how historical temperature biases could impact the detection of ocean heat transport changes in a key area of the South Atlantic Ocean where data are scarce.

scholarly journals What causes long-term temporal changes in the south Atlantic?

2000 ◽  
Vol 27 (8) ◽  
pp. 1187-1190 ◽  
Author(s):  
Jürgen Holfort ◽  
Michael Vanicek ◽  
Gerold Siedler
Keyword(s):  
Temporal Changes ◽  
South Atlantic ◽  
The South

Regional long-term extreme wave analysis using hindcast data from the South Atlantic Ocean

2019 ◽  
Vol 179 ◽  
pp. 202-212 ◽  
Author(s):  
R.M. Campos ◽  
C. Guedes Soares ◽  
J.H.G.M. Alves ◽  
C.E. Parente ◽  
L.G. Guimaraes
Keyword(s):  
Atlantic Ocean ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Wave Analysis ◽  
Extreme Wave ◽  
The South

scholarly journals O gênero Pholadomya Sowerby, 1823 (Mollusca: Bivalvia) na formação Jandaíra (Cretáceo Superior), Bacia Potiguar: implicações paleoecológicas e paleogeográficas

2008 ◽  
Vol 31 (1) ◽  
pp. 88-97
Author(s):  
Natalia Pereira Benaim ◽  
Maria Célia Elias Senra
Keyword(s):  
United States ◽  
United States Of America ◽  
Upper Cretaceous ◽  
South Atlantic ◽  
The South ◽  
Shallow Seas ◽  
Latitudinal Range

Pholadomya Sowerby, 1823 is an anomalodesmatan bivalve that dispersed during Mesozoic, like other Mollusks, colonizating the South Atlantic shallow seas, between Brazil and Africa. On brazilian Cretaceous the sources of Pholadomya are scarce, occurring in outcrops from Algodões Formation, Gramame Formation and Jandaíra Formation, where occurs the species Pholadomya baixaleitensis. Based on specimens from new outcrops of Jandaíra Formation, a new occurrence of P. cf. adversa and P. baixaleitensis are shown and a new morfotype for the genus is described. It was possible to infer that the species studied presented deep endobentonic habits, and burrowed slowly the sediment, probably living their whole life into the same cavity. During Campanian Pholadomya is known from Cameroon, France, Poland, Austria, Germany and other localities in United States of America, occurring in association with other tethyan mollusks. The records of the genus in the marginal equatorial basins enhance the fossil bivalve diversity, and agree with the hypotesis of a south latitudinal range for the Tethyan Realm during Upper Cretaceous.

scholarly journals Meridional Changes in The South Atlantic Subtropical Gyre During Heinrich Stadials

2020 ◽  
Author(s):  
Tainã Pinho ◽  
Cristiano Chiessi ◽  
Rodrigo Portilho-Ramos ◽  
Marília Campos ◽  
Stefano Crivellari ◽  
...  
Keyword(s):  
Global Climate ◽  
South Atlantic ◽  
Subtropical Gyre ◽  
Climate System ◽  
The South ◽  
Foraminiferal Species ◽  
Ocean Gyres ◽  
Long Term Monitoring ◽  
Term Monitoring

Abstract Subtropical ocean gyres play a key role in modulating the global climate system redistributing energy between low and high latitudes. A poleward displacement of the subtropical gyres has been observed over the last decades, but the lack of long-term monitoring data hinders an in-depth understanding of their dynamics. Paleoceanographic records offer the opportunity to identify meridional changes in the subtropical gyres and investigate their consequences to the climate system. Here we use the abundance of planktonic foraminiferal species Globorotalia truncatulinodes from a sediment core collected at the northernmost boundary of the South Atlantic Subtropical Gyre (SASG) together with a previously published record of the same species from the southernmost boundary of the SASG to reconstruct meridional fluctuations of the SASG over last ca. 70 kyr. Our findings indicate southward displacements of the SASG during Heinrich Stadials (HS) 6-4 and HS1, and a contraction of the SASG during HS3 and HS2. During HS6-4 and HS1, the SASG southward displacements likely boosted the transfer of heat to the Southern Ocean, ultimately strengthening deep-water upwelling and CO2 release to the atmosphere. We hypothesize that the ongoing SASG poleward displacement may further increase oceanic CO2 release.

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