scholarly journals Lower oceanic <i>δ</i><sup>13</sup>C during the last interglacial period compared to the Holocene

2021 ◽  
Vol 17 (1) ◽  
pp. 507-528
Author(s):  
Shannon A. Bengtson ◽  
Laurie C. Menviel ◽  
Katrin J. Meissner ◽  
Lise Missiaen ◽  
Carlye D. Peterson ◽  
...  
Keyword(s):  
North Atlantic ◽  
Interglacial Period ◽  
Oceanic Circulation ◽  
Last Interglacial ◽  
The Holocene ◽  
Last Interglacial Period ◽  
Significant Difference ◽  
Depth Extent ◽  
Global Carbon

Abstract. The last time in Earth's history when high latitudes were warmer than during pre-industrial times was the last interglacial period (LIG, 129–116 ka BP). Since the LIG is the most recent and best documented interglacial, it can provide insights into climate processes in a warmer world. However, some key features of the LIG are not well constrained, notably the oceanic circulation and the global carbon cycle. Here, we use a new database of LIG benthic δ13C to investigate these two aspects. We find that the oceanic mean δ13C was ∼ 0.2 ‰ lower during the LIG (here defined as 125–120 ka BP) when compared to the Holocene (7–2 ka BP). A lower terrestrial carbon content at the LIG than during the Holocene could have led to both lower oceanic δ13C and atmospheric δ13CO2 as observed in paleo-records. However, given the multi-millennial timescale, the lower oceanic δ13C most likely reflects a long-term imbalance between weathering and burial of carbon. The δ13C distribution in the Atlantic Ocean suggests no significant difference in the latitudinal and depth extent of North Atlantic Deep Water (NADW) between the LIG and the Holocene. Furthermore, the data suggest that the multi-millennial mean NADW transport was similar between these two time periods.

scholarly journals Lower oceanic 𝛿<sup>13</sup>C during the Last Interglacial compared to the Holocene

2020 ◽  
Author(s):  
Shannon A. Bengtson ◽  
Laurie C. Menviel ◽  
Katrin J. Meissner ◽  
Lise Missiaen ◽  
Carlye D. Peterson ◽  
...  
Keyword(s):  
North Atlantic ◽  
Global Carbon Cycle ◽  
Oceanic Circulation ◽  
Last Interglacial ◽  
The Holocene ◽  
Time Period ◽  
Significant Difference ◽  
Depth Extent ◽  
Global Carbon

Abstract. The last time in Earth’s history when the high latitudes were warmer than during pre-industrial times was the last interglacial (LIG, 129–116 ka BP). Since the LIG is the most recent and best documented warm time period, it can provide insights into climate processes in a warmer world. However, some key features of the LIG are not well constrained, notably the oceanic circulation and the global carbon cycle. Here, we use a new database of LIG benthic 𝛿13C to investigate these two aspects. We find that the oceanic mean 𝛿13C was ~ 0.2 ‰ lower during the LIG (here defined as 125–120 ka BP) when compared to the mid-Holocene (7–4 ka BP). As the LIG was slightly warmer than the Holocene, it is possible that terrestrial carbon was lower, which would have led to both a lower oceanic 𝛿13C and atmospheric 𝛿13CO2 as observed in paleo-records. However, given the multi-millennial timescale, the lower oceanic 𝛿13C most likely reflects a long-term imbalance between weathering and burial of carbon. The 𝛿13C distribution in the Atlantic Ocean suggests no significant difference in the latitudinal and depth extent of North Atlantic Deep Water (NADW) between the LIG and the mid-Holocene. Furthermore, the data suggests that the multi-millennial mean NADW transport was similar between these two time periods.

Variability of the North Atlantic thermohaline circulation during the last interglacial period

Nature ◽  
10.1038/36540 ◽  
1997 ◽  
Vol 390 (6656) ◽  
pp. 154-156 ◽  
Author(s):  
Jess F. Adkins§ ◽  
Edward A. Boyle ◽  
Lloyd Keigwin ◽  
Elsa Cortijo
Keyword(s):  
North Atlantic ◽  
Thermohaline Circulation ◽  
Interglacial Period ◽  
Last Interglacial ◽  
The North ◽  
Last Interglacial Period ◽  
The North Atlantic ◽  
Atlantic Thermohaline Circulation

scholarly journals Differences in water mass geometry in the Atlantic Ocean during the Holocene and the last interglacial period

2021 ◽  
Author(s):  
Julia Gottschalk ◽  
Frerk Pöppelmeier ◽  
Patrick Blaser ◽  
Marcus Gutjahr ◽  
Sophia Hines ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Water Mass ◽  
Interglacial Period ◽  
Last Interglacial ◽  
The Holocene ◽  
Last Interglacial Period

scholarly journals A tropical speleothem record of glacial inception, the South American Summer Monsoon from 125 to 115 ka

2015 ◽  
Vol 11 (6) ◽  
pp. 931-938 ◽  
Author(s):  
S. J. Burns ◽  
L. C. Kanner ◽  
H. Cheng ◽  
R. Lawrence Edwards
Keyword(s):  
Summer Monsoon ◽  
East Asian Monsoon ◽  
Interglacial Period ◽  
South American ◽  
Last Interglacial ◽  
Peruvian Andes ◽  
Northern Latitudes ◽  
Last Interglacial Period ◽  
Rapid Changes

Abstract. Relatively few marine or terrestrial paleoclimate studies have focused on glacial inception, the transition from an interglacial to a glacial climate state. As a result, neither the timing and structure of glacial inception nor the spatial pattern of glacial inception in different parts of the world is well known. Here we present results of a study of a speleothem from the Peruvian Andes that records changes in the intensity of South American Summer Monsoon (SASM) rainfall over the period from 125 to 115 ka. The results show that late in the last interglacial period, at 123 ka, SASM rainfall decreased, perhaps in response to a decrease in temperature and ice cover in the high northern latitudes and associated changes in atmospheric circulation. Then at 120.8 ka, a rapid increase in SASM rainfall marks the end of the last interglacial. After a more gradual increase between 120 and 117 ka, a second abrupt increase occurs at 117 ka. This pattern of change is mirrored to a remarkable degree by changes in the East Asian Monsoon. It is interpreted to reflect both a long-term gradual response of the monsoons to orbitally driven insolation changes and to rapid changes in Northern Hemisphere ice volume and temperature. Both monsoon systems are close to their full glacial conditions by 117 ka, before any significant decrease in atmospheric CO2.

Introduction to the Snowmastodon Project Special Volume The Snowmastodon Project

2014 ◽  
Vol 82 (3) ◽  
pp. 473-476 ◽  
Author(s):  
Kirk R. Johnson ◽  
Ian M. Miller ◽  
Jeffrey S. Pigati ◽  
Keyword(s):  
High Elevation ◽  
Interglacial Period ◽  
Alpine Ecosystems ◽  
Special Volume ◽  
Last Interglacial ◽  
Oxygen Isotope Stage ◽  
Last Interglacial Period ◽  
Mis 5 ◽  
Insight Into

Studies of terrestrial biotic and environmental dynamics of Marine Oxygen Isotope Stage (MIS) 5, also called the Last Interglacial Period, provide insight into the effects of long-term climate change on Pleistocene ecosystems. In North America, however, there are relatively few fossil sites that definitively date to MIS 5. Even fewer contain multiple ecosystem components (vertebrates, invertebrates, plants) that have been studied in detail, and none are located at high elevation. Thus, our view of North American ecosystems during MIS 5 is, at best, an incomplete composite view, and alpine ecosystems are entirely undocumented.

A stagnation event in the deep South Atlantic during the last interglacial period

Science ◽  
2014 ◽  
Vol 346 (6216) ◽  
pp. 1514-1517 ◽  
Author(s):  
Christopher T. Hayes ◽  
Alfredo Martínez-García ◽  
Adam P. Hasenfratz ◽  
Samuel L. Jaccard ◽  
David A. Hodell ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Ice Age ◽  
Interglacial Period ◽  
Deep South ◽  
Last Interglacial ◽  
The North ◽  
Last Interglacial Period ◽  
Water Formation ◽  
The Antarctic

During the last interglacial period, global temperatures were ~2°C warmer than at present and sea level was 6 to 8 meters higher. Southern Ocean sediments reveal a spike in authigenic uranium 127,000 years ago, within the last interglacial, reflecting decreased oxygenation of deep water by Antarctic Bottom Water (AABW). Unlike ice age reductions in AABW, the interglacial stagnation event appears decoupled from open ocean conditions and may have resulted from coastal freshening due to mass loss from the Antarctic ice sheet. AABW reduction coincided with increased North Atlantic Deep Water (NADW) formation, and the subsequent reinvigoration in AABW coincided with reduced NADW formation. Thus, alternation of deep water formation between the Antarctic and the North Atlantic, believed to characterize ice ages, apparently also occurs in warm climates.

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