scholarly journals Origin of Abyssal NW Atlantic Water Masses Since the Last Glacial Maximum

2018 ◽  
Vol 33 (5) ◽  
pp. 530-543 ◽  
Author(s):  
F. Pöppelmeier ◽  
M. Gutjahr ◽  
P. Blaser ◽  
L. D. Keigwin ◽  
J. Lippold
Keyword(s):  
Last Glacial Maximum ◽  
Atlantic Water ◽  
Glacial Maximum ◽  
Water Masses ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Evolution of the deep Atlantic water masses since the last glacial maximum based on a transient run of NCAR-CCSM3

2015 ◽  
Vol 47 (3-4) ◽  
pp. 865-877 ◽  
Author(s):  
Juliana M. Marson ◽  
Lawrence A. Mysak ◽  
Mauricio M. Mata ◽  
Ilana Wainer
Keyword(s):  
Last Glacial Maximum ◽  
Atlantic Water ◽  
Glacial Maximum ◽  
Water Masses ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

scholarly journals Evidence for influx of Atlantic water masses to the Labrador Sea during the Last Glacial Maximum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marit-Solveig Seidenkrantz ◽  
Antoon Kuijpers ◽  
Steffen Aagaard-Sørensen ◽  
Holger Lindgreen ◽  
Jesper Olsen ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Deep Water ◽  
Glacial Maximum ◽  
Water Masses ◽  
Meridional Overturning Circulation ◽  
Labrador Sea ◽  
Last Glacial ◽  
Water Signal ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractThe Last Glacial Maximum (LGM, 23–19,000 year BP) designates a period of extensive glacial extent and very cold conditions on the Northern Hemisphere. The strength of ocean circulation during this period has been highly debated. Based on investigations of two marine sediment cores from the Davis Strait (1033 m water depth) and the northern Labrador Sea (2381 m), we demonstrate a significant influx of Atlantic-sourced water at both subsurface and intermediate depths during the LGM. Although surface-water conditions were cold and sea-ice loaded, the lower strata of the (proto) West Greenland Current carried a significant Atlantic (Irminger Sea-derived) Water signal, while at the deeper site the sea floor was swept by a water mass comparable with present Northeast Atlantic Deep Water. The persistent influx of these Atlantic-sourced waters entrained by boundary currents off SW Greenland demonstrates an active Atlantic Meridional Overturning Circulation during the LGM. Immediately after the LGM, deglaciation was characterized by a prominent deep-water ventilation event and potentially Labrador Sea Water formation, presumably related to brine formation and/or hyperpycnal meltwater flows. This was followed by a major re-arrangement of deep-water masses most likely linked to increased overflow at the Greenland-Scotland Ridge after ca 15 kyr BP.

scholarly journals The impacts of deglacial meltwater forcing on the South Atlantic Ocean deep circulation since the Last Glacial Maximum

2014 ◽  
Vol 10 (5) ◽  
pp. 1723-1734 ◽  
Author(s):  
J. M. Marson ◽  
I. Wainer ◽  
M. M. Mata ◽  
Z. Liu
Keyword(s):  
Last Glacial Maximum ◽  
Atlantic Water ◽  
South Atlantic ◽  
Glacial Maximum ◽  
Meridional Overturning Circulation ◽  
The South ◽  
Climate System Model ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. A NCAR-CCSM3 (National Center for Atmospheric Research – Community Climate System Model version 3) state-of-the-art transient paleoclimate simulation with prescribed freshwater inflows is used to investigate the changes and evolution of the South Atlantic water mass structure from the Last Glacial Maximum (LGM) to the present day. Model results show that 21 000 yr ago the water column was substantially stratified due to the presence of a saltier-than-today Antarctic Bottom Water (AABW), forming a salinity barrier that prevented dense waters from the Northern Hemisphere from sinking. This salinity barrier started to erode after the termination of the Heinrich event 1, when its associated meltwater was transported southward, freshening the AABW. The removal of the barrier after 14 ka triggered the production of the North Atlantic Deep Water (NADW), which spread into the deeper layers of the South Atlantic at the onset of the Holocene. At this point, the NADW acquired its modern-day structure, establishing a deeper Atlantic meridional overturning circulation (AMOC).

scholarly journals Similar mid-depth Atlantic water mass provenance during the Last Glacial Maximum and Heinrich Stadial 1

2018 ◽  
Vol 490 ◽  
pp. 51-61 ◽  
Author(s):  
Jacob N.W. Howe ◽  
Kuo-Fang Huang ◽  
Delia W. Oppo ◽  
Cristiano M. Chiessi ◽  
Stefan Mulitza ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Water Mass ◽  
Atlantic Water ◽  
Glacial Maximum ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum

2021 ◽  
pp. 10-17
Author(s):  
Oguz Turkozan
Keyword(s):  
Middle East ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Testudo Graeca ◽  
Last Glacial ◽  
The Past ◽  
Precipitation Seasonality ◽  
Multiple Refugia ◽  
The Last Glacial Maximum ◽  
The Last Glacial

A cycle of glacial and interglacial periods in the Quaternary caused species’ ranges to expand and contract in response to climatic and environmental changes. During interglacial periods, many species expanded their distribution ranges from refugia into higher elevations and latitudes. In the present work, we projected the responses of the five lineages of Testudo graeca in the Middle East and Transcaucasia as the climate shifted from the Last Glacial Maximum (LGM, Mid – Holocene), to the present. Under the past LGM and Mid-Holocene bioclimatic conditions, models predicted relatively more suitable habitats for some of the lineages. The most significant bioclimatic variables in predicting the present and past potential distribution of clades are the precipitation of the warmest quarter for T. g. armeniaca (95.8 %), precipitation seasonality for T. g. buxtoni (85.0 %), minimum temperature of the coldest month for T. g. ibera (75.4 %), precipitation of the coldest quarter for T. g. terrestris (34.1 %), and the mean temperature of the driest quarter for T. g. zarudyni (88.8 %). Since the LGM, we hypothesise that the ranges of lineages have either expanded (T. g. ibera), contracted (T. g. zarudnyi) or remained stable (T. g. terrestris), and for other two taxa (T. g. armeniaca and T. g. buxtoni) the pattern remains unclear. Our analysis predicts multiple refugia for Testudo during the LGM and supports previous hypotheses about high lineage richness in Anatolia resulting from secondary contact.

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