scholarly journals Direct ventilation of the North Pacific did not reach the deep ocean during the last deglaciation

2013 ◽  
Vol 40 (1) ◽  
pp. 199-203 ◽  
Author(s):  
S. L. Jaccard ◽  
E. D. Galbraith
Keyword(s):  
North Pacific ◽  
Deep Ocean ◽  
Last Deglaciation ◽  
The North ◽  
The Last Deglaciation ◽  
The North Pacific

scholarly journals Wind‐Driven Evolution of the North Pacific Subpolar Gyre Over the Last Deglaciation

2020 ◽  
Vol 47 (6) ◽  
Author(s):  
William R. Gray ◽  
Robert C. J. Wills ◽  
James W. B. Rae ◽  
Andrea Burke ◽  
Ruza F. Ivanovic ◽  
...  
Keyword(s):  
North Pacific ◽  
Subpolar Gyre ◽  
Last Deglaciation ◽  
The North ◽  
The Last Deglaciation ◽  
The North Pacific

scholarly journals Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation

2019 ◽  
Author(s):  
William Robert Gray ◽  
Robert C. J. Wills ◽  
James William Buchanan Rae ◽  
Andrea Burke ◽  
Ruza F Ivanovic ◽  
...  
Keyword(s):  
North Pacific ◽  
Subpolar Gyre ◽  
Last Deglaciation ◽  
The North ◽  
The Last Deglaciation ◽  
The North Pacific

scholarly journals Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation

2019 ◽  
Author(s):  
William Gray ◽  
Robert Jnglin Wills ◽  
James Rae ◽  
Andrea Burke ◽  
Ruza Ivanovic ◽  
...  
Keyword(s):  
North Pacific ◽  
Subpolar Gyre ◽  
Last Deglaciation ◽  
The North ◽  
The Last Deglaciation ◽  
The North Pacific

Carbon dioxide release from the North Pacific abyss during the last deglaciation

Nature ◽  
2007 ◽  
Vol 449 (7164) ◽  
pp. 890-893 ◽  
Author(s):  
Eric D. Galbraith ◽  
Samuel L. Jaccard ◽  
Thomas F. Pedersen ◽  
Daniel M. Sigman ◽  
Gerald H. Haug ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
North Pacific ◽  
Last Deglaciation ◽  
The North ◽  
Carbon Dioxide Release ◽  
The Last Deglaciation ◽  
The North Pacific

scholarly journals Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation

2014 ◽  
Vol 10 (3) ◽  
pp. 2467-2518 ◽  
Author(s):  
H. Kuehn ◽  
L. Lembke-Jene ◽  
R. Gersonde ◽  
O. Esper ◽  
F. Lamy ◽  
...  
Keyword(s):  
Bering Sea ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Ice Core ◽  
Laminated Sediments ◽  
Temperature Threshold ◽  
Last Deglaciation ◽  
The North ◽  
Decadal Scale ◽  
The Last Deglaciation

Abstract. During the last glacial termination, the upper North Pacific Ocean underwent dramatic and rapid changes in oxygenation that lead to the transient intensification of Oxygen Minimum Zones (OMZs), recorded by the widespread occurrence of laminated sediments on circum-Pacific continental margins. We present a new laminated sediment record from the mid-depth (1100 m) northern Bering Sea margin that provides insight into these deglacial OMZ maxima with exceptional, decadal-scale detail. Combined ultrahigh-resolution micro-XRF data and sediment facies analysis of laminae reveals an alternation between predominantly terrigenous and diatom-dominated opal sedimentation. The diatomaceous laminae are interpreted to represent spring/summer productivity events that occur at the retreating sea ice margin. We identified five laminated sections in the deglacial part of our site. Laminae counts were carried out on these sections and correlated to the Bølling–Allerød and Preboreal phases in North Greenland Ice Core (NGRIP) oxygen isotope record, indicating an annual deposition of individual laminae couplets. The observed rapid intra-decadal intensifications of anoxia, in particular within the Bølling–Allerød, are tightly coupled to short-term warm events through increases in regional biogenic productivity. By correlating the counted laminated sections with Bering Sea Surface Temperature records (SST) and NGRIP δ18O data, we propose a deglacial minimum SST of 6–7 °C for the preservation of laminae, which we call the deglacial temperature threshold for anoxia occurrence, a process that strongly implies a close atmospheric teleconnection between the North Pacific and North Atlantic regions. We suggest that concomitant increases in Bering Sea biogenic productivity, in combination with oxygen-poor waters entering the Being Sea, drove down oxygen concentrations to values below 0.1 mL L-1 and caused laminae preservation. Calculated benthic-planktic ventilation ages show no significant variations throughout the last deglaciation, indicating that changes in formation rates or differing sources of North Pacific mid-depth waters are not prime candidates for strengthening the OMZ at our site. The age models established by our correlation procedure allow to determine calendar age control points for the Bølling–Allerød and the Preboreal that are independent of the initial radiocarbon-based chronology. Resulting calculated reservoir ages are 875 yr during the Bølling–Allerød, and 910–770 yr for the Younger Dryas and the Preboreal, respectively.

scholarly journals Millennial-scale variations in sedimentary oxygenation in the western subtropical North Pacific and its links to North Atlantic climate

2020 ◽  
Vol 16 (1) ◽  
pp. 387-407 ◽  
Author(s):  
Jianjun Zou ◽  
Xuefa Shi ◽  
Aimei Zhu ◽  
Selvaraj Kandasamy ◽  
Xun Gong ◽  
...  
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Deep Ocean ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Intermediate Water ◽  
The North ◽  
Geochemical Parameters ◽  
The North Pacific ◽  
Millennial Scale

Abstract. The deep-ocean carbon cycle, especially carbon sequestration and outgassing, is one of the mechanisms to explain variations in atmospheric CO2 concentrations on millennial and orbital timescales. However, the potential role of subtropical North Pacific subsurface waters in modulating atmospheric CO2 levels on millennial timescales is poorly constrained. An increase in the respired CO2 concentration in the glacial deep-ocean due to biological pump generally corresponds to deoxygenation in the ocean interior. This link thus offers a chance to study oceanic ventilation and coeval export productivity based on redox-controlled sedimentary geochemical parameters. Here, we investigate a suite of geochemical proxies in a sediment core from the Okinawa Trough to understand sedimentary oxygenation variations in the subtropical North Pacific over the last 50 000 years (50 ka). Our results suggest that enhanced mid-depth western subtropical North Pacific (WSTNP) sedimentary oxygenation occurred during cold intervals and after 8.5 ka, while oxygenation decreased during the Bölling-Alleröd (B/A) and Preboreal. The enhanced oxygenation during cold spells is linked to the North Pacific Intermediate Water (NPIW), while interglacial increase after 8.5 ka is linked to an intensification of the Kuroshio Current due to strengthened northeast trade winds over the tropics. The enhanced formation of the NPIW during Heinrich Stadial 1 (HS1) was likely driven by the perturbation of sea ice formation and sea surface salinity oscillations in the high-latitude North Pacific. The diminished sedimentary oxygenation during the B/A due to a decreased NPIW formation and enhanced export production, indicates an expansion of the oxygen minimum zone in the North Pacific and enhanced CO2 sequestration at mid-depth waters, along with the termination of atmospheric CO2 concentration increase. We attribute the millennial-scale changes to an intensified NPIW and enhanced abyss flushing during deglacial cold and warm intervals, respectively, closely related to variations in North Atlantic Deep Water formation.

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