scholarly journals Reduced admixture of North Atlantic Deep Water to the deep central South Pacific during the last two glacial periods

2016 ◽  
Vol 31 (6) ◽  
pp. 651-668 ◽  
Author(s):  
Mario Molina‐Kescher ◽  
Martin Frank ◽  
Raúl Tapia ◽  
Thomas A. Ronge ◽  
Dirk Nürnberg ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
South Pacific ◽  
North Atlantic Deep Water ◽  
Glacial Periods ◽  
Central South

scholarly journals Post-Eocene intensification of deep-water circulation in the central South Pacific: Micropalaeontological clues from dredged sites along the eastern Manihiki Plateau margin

Terra Nova ◽  
2018 ◽  
Vol 31 (1) ◽  
pp. 28-38
Author(s):  
Atsushi Ando ◽  
Junichiro Kuroda ◽  
Reinhard Werner ◽  
Kaj Hoernle ◽  
Brian T. Huber
Keyword(s):  
Deep Water ◽  
South Pacific ◽  
Water Circulation ◽  
Central South ◽  
Manihiki Plateau

Identification and quantification of the North Atlantic Deep Water pathways

2021 ◽  
Author(s):  
Philippe Miron ◽  
Maria J. Olascoaga ◽  
Francisco J. Beron-Vera ◽  
Kimberly L. Drouin ◽  
M. Susan Lozier
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Sea Water ◽  
Lower Layer ◽  
North Atlantic Deep Water ◽  
Meridional Overturning Circulation ◽  
Labrador Sea ◽  
Western Boundary ◽  
The North ◽  
The North Atlantic

<p>The North Atlantic Deep Water (NADW) flows equatorward along the Deep Western Boundary Current (DWBC) as well as interior pathways and is a critical part of the Atlantic Meridional Overturning Circulation. Its upper layer, the Labrador Sea Water (LSW), is formed by open-ocean deep convection in the Labrador and Irminger Seas while its lower layers, the Iceland–Scotland Overflow Water (ISOW) and the Denmark Strait Overflow Water (DSOW), are formed north of the Greenland–Iceland–Scotland Ridge.</p><p>In recent years, more than two hundred acoustically-tracked subsurface floats have been deployed in the deep waters of the North Atlantic.  Studies to date have highlighted water mass pathways from launch locations, but due to limited float trajectory lengths, these studies have been unable to identify pathways connecting  remote regions.</p><p>This work presents a framework to explore deep water pathways from their respective sources in the North Atlantic using Markov Chain (MC) modeling and Transition Path Theory (TPT). Using observational trajectories released as part of OSNAP and the Argo projects, we constructed two MCs that approximate the lower and upper layers of the NADW Lagrangian dynamics. The reactive NADW pathways—directly connecting NADW sources with a target at 53°N—are obtained from these MCs using TPT.</p><p>Preliminary results show that twenty percent more pathways of the upper layer(LSW) reach the ocean interior compared to  the lower layer (ISOW, DSOW), which mostly flows along the DWBC in the subpolar North Atlantic. Also identified are the Labrador Sea recirculation pathways to the Irminger Sea and the direct connections from the Reykjanes Ridge to the eastern flank of the Mid–Atlantic Ridge, both previously observed. Furthermore, we quantified the eastern spread of the LSW to the area surrounding the Charlie–Gibbs Fracture Zone and compared it with previous analysis. Finally, the residence time of the upper and lower layers are assessed and compared to previous observations.</p>

scholarly journals Publisher Correction: Glacial–interglacial Nd isotope variability of North Atlantic Deep Water modulated by North American ice sheet

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ning Zhao ◽  
Delia W. Oppo ◽  
Kuo-Fang Huang ◽  
Jacob N. W. Howe ◽  
Jerzy Blusztajn ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
North American ◽  
Ice Sheet ◽  
North Atlantic Deep Water ◽  
Nd Isotope

scholarly journals A circumpolar dust conveyor in the glacial Southern Ocean

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Torben Struve ◽  
Katharina Pahnke ◽  
Frank Lamy ◽  
Marc Wengler ◽  
Philipp Böning ◽  
...  
Keyword(s):  
South America ◽  
Southern Ocean ◽  
Net Primary Production ◽  
South Pacific ◽  
Dust Deposition ◽  
Carbon Export ◽  
Transport Pathways ◽  
Dust Transport ◽  
Glacial Periods ◽  
Central South

Abstract The increased flux of soluble iron (Fe) to the Fe-deficient Southern Ocean by atmospheric dust is considered to have stimulated the net primary production and carbon export, thus promoting atmospheric CO2 drawdown during glacial periods. Yet, little is known about the sources and transport pathways of Southern Hemisphere dust during the Last Glacial Maximum (LGM). Here we show that Central South America (~24‒32°S) contributed up to ~80% of the dust deposition in the South Pacific Subantarctic Zone via efficient circum-Antarctic dust transport during the LGM, whereas the Antarctic Zone was dominated by dust from Australia. This pattern is in contrast to the modern/Holocene pattern, when South Pacific dust fluxes are thought to be primarily supported by Australian sources. Our findings reveal that in the glacial Southern Ocean, Fe fertilization critically relies on the dynamic interaction of changes in dust-Fe sources in Central South America with the circumpolar westerly wind system.

Late Pliocene variation in northern hemisphere ice sheets and North Atlantic deep water circulation

1989 ◽  
Vol 4 (4) ◽  
pp. 413-446 ◽  
Author(s):  
M. E. Raymo ◽  
W. F. Ruddiman ◽  
J. Backman ◽  
B. M. Clement ◽  
D. G. Martinson
Keyword(s):  
Northern Hemisphere ◽  
North Atlantic ◽  
Deep Water ◽  
Ice Sheets ◽  
North Atlantic Deep Water ◽  
Water Circulation ◽  
Late Pliocene
Sign in / Sign up

Export Citation Format

Share Document