scholarly journals Was millennial scale climate change during the Last Glacial triggered by explosive volcanism?

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
James U.L. Baldini ◽  
Richard J. Brown ◽  
Jim N. McElwaine
Keyword(s):  
Climate Change ◽  
Explosive Volcanism ◽  
Last Glacial ◽  
The Last Glacial ◽  
Millennial Scale

scholarly journals <i>δ</i><sup>13</sup>C decreases in the upper western South Atlantic during Heinrich Stadials 3 and 2

2017 ◽  
Vol 13 (4) ◽  
pp. 345-358 ◽  
Author(s):  
Marília C. Campos ◽  
Cristiano M. Chiessi ◽  
Ines Voigt ◽  
Alberto R. Piola ◽  
Henning Kuhnert ◽  
...  
Keyword(s):  
Climate Change ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Glacial Period ◽  
Last Deglaciation ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Change Events ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Abrupt millennial-scale climate change events of the last deglaciation (i.e. Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 (CO2atm) and decreases in its stable carbon isotopic ratios (δ13C), i.e. δ13CO2atm, presumably due to outgassing from the ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present δ13C records from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1 ‰) during Heinrich Stadials 3 and 2. These δ13C decreases are most likely related to millennial-scale periods of weakening of the Atlantic meridional overturning circulation and the consequent increase (decrease) in CO2atm (δ13CO2atm). We hypothesise two mechanisms that could account for the decreases observed in our records, namely strengthening of Southern Ocean deep-water ventilation and weakening of the biological pump. Additionally, we suggest that air–sea gas exchange could have contributed to the observed δ13C decreases. Together with other lines of evidence, our data are consistent with the hypothesis that the CO2 added to the atmosphere during abrupt millennial-scale climate change events of the last glacial period also originated in the ocean and reached the atmosphere by outgassing. The temporal evolution of δ13C during Heinrich Stadials 3 and 2 in our records is characterized by two relative minima separated by a relative maximum. This w structure is also found in North Atlantic and South American records, further suggesting that such a structure is a pervasive feature of Heinrich Stadial 2 and, possibly, also Heinrich Stadial 3.

Timing of millennial-scale climate change at Siple Dome, West Antarctica, during the last glacial period

2005 ◽  
Vol 24 (12-13) ◽  
pp. 1333-1343 ◽  
Author(s):  
Edward J. Brook ◽  
James W.C. White ◽  
Annie S.M. Schilla ◽  
Michael L. Bender ◽  
Bruce Barnett ◽  
...  
Keyword(s):  
Climate Change ◽  
Glacial Period ◽  
West Antarctica ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Siple Dome ◽  
The Last Glacial ◽  
Millennial Scale

scholarly journals Glacial δ<sup>13</sup>C decreases in the western South Atlantic forced by millennial changes in Southern Ocean ventilation

2016 ◽  
Author(s):  
Marília C. Campos ◽  
Cristiano M. Chiessi ◽  
Ines Voigt ◽  
Alberto R. Piola ◽  
Henning Kuhnert ◽  
...  
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
South Atlantic ◽  
Meridional Overturning Circulation ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Change Events ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. Abrupt millennial–scale climate change events of the last deglaciation (i.e., Heinrich Stadial 1 and the Younger Dryas) were accompanied by marked increases in atmospheric CO2 presumably originated by outgassing from the Southern Ocean. However, information on the preceding Heinrich Stadials during the last glacial period is scarce. Here we present stable carbon isotopic data (δ13C) from two species of planktonic foraminifera from the western South Atlantic that reveal major decreases (up to 1 ‰) during Heinrich Stadials 3 and 2. These δ13C decreases are most likely related to millennial–scale periods of intensification in Southern Ocean deep water ventilation presumably associated with a weak Atlantic meridional overturning circulation. After reaching the upper water column of the Southern Ocean, the δ13C depletion would be transferred equatorward via central and thermocline waters. Together with other lines of evidence, our data are consistent with the hypothesis that the CO2 added to the atmosphere during abrupt millennial–scale climate change events during the last glacial period also originated in the ocean and reached the atmosphere by outgassing from the Southern Ocean. The temporal evolution of δ13C during Heinrich Stadials in our records is characterized by two relative minima separated by a relative maximum. This “w–structure” is also found in North Atlantic and South American records, giving us confidence that such structure is a pervasive feature of Heinrich Stadial 2 and, possibly, also Heinrich Stadial 3.

Atmospheric CO2 concentration and millennial-scale climate change during the last glacial period

Nature ◽  
10.1038/32133 ◽  
1998 ◽  
Vol 392 (6671) ◽  
pp. 59-62 ◽  
Author(s):  
B. Stauffer ◽  
T. Blunier ◽  
A. Dällenbach ◽  
A. Indermühle ◽  
J. Schwander ◽  
...  
Keyword(s):  
Climate Change ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Last Glacial ◽  
Atmospheric Co2 Concentration ◽  
The Last Glacial ◽  
Millennial Scale
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