Isotopes of molecular nitrogen, oxygen, and argon in the South Pole ice core document local and global climate change through the last deglaciation.

2021 ◽  
Author(s):  
Jacob Morgan ◽  
Christo Buizert ◽  
Jeff Severinghaus
Keyword(s):  
Global Climate ◽  
Molecular Nitrogen ◽  
Ice Core ◽  
South Pole ◽  
Last Deglaciation ◽  
The South ◽  
Temperature Changes ◽  
Temperature Proxy ◽  
Local Surface Temperature ◽  
First Time

<p>Ice core gas records are an invaluable paleoclimatic archive. The three most abundant gases in air, nitrogen (N<sub>2</sub>), oxygen (O<sub>2</sub>), and argon (Ar), provide paleoclimatic information about both global and regional processes including tropical rainfall patterns and local surface temperature changes. We present a large dataset of elemental and isotopic ratios of N<sub>2</sub>, O<sub>2</sub>, and Ar (O<sub>2</sub>/N<sub>2</sub>, Ar/N<sub>2</sub>, δ<sup>15</sup>N, δ<sup>18</sup>O, & δ<sup>40</sup>Ar) from the South Pole Ice Core between 0 – 52,000 yr BP, with a focus on high precision δ<sup>15</sup>N and δ<sup>40</sup>Ar measurements between 5,000 – 32,000 yr BP. The unprecedented precision of our measurements allows us to use δ<sup>15</sup>N<sub>excess </sub>(= δ<sup>15</sup>N - δ<sup>40</sup>Ar/4) to reconstruct past temperature change at the South Pole. Although this proxy has been widely applied in Greenland, this is the first time it has been successfully applied to Antarctic ice and provides a valuable independent check on the more traditional water isotopes temperature proxy. We find good agreement between the two during the relatively stable climate of the glacial period and the Holocene. However the temperature reconstructions diverge during the deglaciation. We present several hypotheses that could explain the discrepancy and look to other emerging ice core temperature proxies to support our interpretation.</p>

scholarly journals Ranges of moisture-source temperatures estimated from Antarctic ice core stable isotope records over the glacial-interglacial cycles

2012 ◽  
Vol 8 (1) ◽  
pp. 391-434 ◽  
Author(s):  
R. Uemura ◽  
V. Masson-Delmotte ◽  
J. Jouzel ◽  
A. Landais ◽  
H. Motoyama ◽  
...  
Keyword(s):  
Air Temperature ◽  
Ice Core ◽  
Ice Cores ◽  
Regression Equations ◽  
Temperature Changes ◽  
Moisture Source ◽  
Isotopic Model ◽  
Temperature Proxy ◽  
Coefficient Of Regression ◽  
First Time

Abstract. A single isotope ratio (δD or δ18O) of water is widely used as an air-temperature proxy in Antarctic ice cores. These isotope ratios, however, do not solely depend on air-temperature but also on the extent of distillation of heavy isotopes out of atmospheric water vapor from an oceanic moisture source to a precipitation site. The temperature changes at the oceanic moisture source (ΔTsource) and at the precipitation site (ΔTsite) can be retrieved by using deuterium-excess (d) data. A new d record from Dome Fuji, Antarctica is produced spanning the past 360 000 yr and compared with records from Vostok and EPICA Dome C ice cores. To retrieve ΔTsource and ΔTsite information, different linear regression equations have been proposed using theoretical isotope distillation models. A major source of uncertainty lies in the coefficient of regression, βsite which is related to the sensitivity of d to ΔTsite. We show that different ranges of temperature and selections of isotopic model outputs may increase the value of βsite by a factor of two. To explore the impacts of this coefficient on the reconstructed temperatures, we apply for the first time the exact same methodology to the isotope records from the three Antarctica ice cores. We show that uncertainties in the βsite coefficient strongly affect (i) the glacial-interglacial magnitude of ΔTsource; (ii) the imprint of obliquity in ΔTsource and in the site-source temperature gradient. By contrast, we highlight the robustness of ΔTsite reconstruction using water isotopes records.

scholarly journals A New 14C Calibration Data Set for the Last Deglaciation Based on Marine Varves

Radiocarbon ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 483-494 ◽  
Author(s):  
Konrad A. Hughen ◽  
Jonathan T. Overpeck ◽  
Scott J. Lehman ◽  
Michaele Kashgarian ◽  
John R. Southon ◽  
...  
Keyword(s):  
Global Climate ◽  
Ice Core ◽  
Younger Dryas ◽  
Core Layer ◽  
Cariaco Basin ◽  
Calibration Data ◽  
Last Deglaciation ◽  
Data Set ◽  
The Last Deglaciation ◽  
Calibration Data Set

Varved sediments of the tropical Cariaco Basin provide a new 14C calibration data set for the period of deglaciation (10,000 to 14,500 years before present: 10–14.5 cal ka bp). Independent evaluations of the Cariaco Basin calendar and 14C chronologies were based on the agreement of varve ages with the GISP2 ice core layer chronology for similar high-resolution paleoclimate records, in addition to 14C age agreement with terrestrial 14C dates, even during large climatic changes. These assessments indicate that the Cariaco Basin 14C reservoir age remained stable throughout the Younger Dryas and late Allerød climatic events and that the varve and 14C chronologies provide an accurate alternative to existing calibrations based on coral U/Th dates. The Cariaco Basin calibration generally agrees with coral-derived calibrations but is more continuous and resolves century-scale details of 14C change not seen in the coral records. 14C plateaus can be identified at 9.6, 11.4, and 11.7 14C ka bp, in addition to a large, sloping “plateau” during the Younger Dryas (∼10 to 11 14C ka bp). Accounting for features such as these is crucial to determining the relative timing and rates of change during abrupt global climate changes of the last deglaciation.

scholarly journals Ranges of moisture-source temperature estimated from Antarctic ice cores stable isotope records over glacial–interglacial cycles

2012 ◽  
Vol 8 (3) ◽  
pp. 1109-1125 ◽  
Author(s):  
R. Uemura ◽  
V. Masson-Delmotte ◽  
J. Jouzel ◽  
A. Landais ◽  
H. Motoyama ◽  
...  
Keyword(s):  
Air Temperature ◽  
Ice Core ◽  
Ice Cores ◽  
Regression Equations ◽  
Temperature Changes ◽  
Source Temperature ◽  
Moisture Source ◽  
Isotopic Model ◽  
Temperature Proxy ◽  
Coefficient Of Regression

Abstract. A single isotope ratio (δD or δ18O) of water is widely used as an air-temperature proxy in Antarctic ice core records. These isotope ratios, however, do not solely depend on air-temperature but also on the extent of distillation of heavy isotopes out of atmospheric water vapor from an oceanic moisture source to a precipitation site. The temperature changes at the oceanic moisture source (Δ Tsource) and at the precipitation site (Δ Tsite) can be retrieved by using deuterium-excess (d) data. A new d record from Dome Fuji, Antarctica spanning the past 360 000 yr is presented and compared with records from Vostok and EPICA Dome C ice cores. In previous studies, to retrieve Δ Tsource and Δ Tsite information, different linear regression equations were proposed using theoretical isotope distillation models. A major source of uncertainty lies in the coefficient of regression, βsite which is related to the sensitivity of d to Δ Tsite. We show that different ranges of temperature and selections of isotopic model outputs may increase the value of βsite by more than a factor of two. To explore the impacts of this coefficient on reconstructed temperatures, we apply for the first time the exact same methodology to the isotope records from the three Antarctica ice cores. We show that uncertainties in the βsite coefficient strongly affect (i) the glacial–interglacial magnitude of Δ Tsource; (ii) the imprint of obliquity in Δ Tsource and in the site-source temperature gradient. By contrast, we highlight the robustness of Δ Tsite reconstruction using water isotopes records.

scholarly journals Modeling ice birefringence and oblique radio wave propagation for neutrino detection at the South Pole

2020 ◽  
Vol 61 (81) ◽  
pp. 84-91 ◽  
Author(s):  
T. M. Jordan ◽  
D. Z. Besson ◽  
I. Kravchenko ◽  
U. Latif ◽  
B. Madison ◽  
...  
Keyword(s):  
Time Delays ◽  
Ice Core ◽  
High Energy ◽  
Propagation Model ◽  
Neutrino Interaction ◽  
Crystallographic Axis ◽  
South Pole ◽  
The South ◽  
Range Estimation ◽  
Ice Flow

AbstractThe Askaryan Radio Array (ARA) experiment at the South Pole is designed to detect high-energy neutrinos which, via in-ice interactions, produce coherent radiation at frequencies up to 1000 MHz. Characterization of ice birefringence, and its effect upon wave polarization, is proposed to enable range estimation to a neutrino interaction and hence aid in neutrino energy reconstruction. Using radio transmitter calibration sources, the ARA collaboration recently measured polarization-dependent time delay variations and reported significant time delays for trajectories perpendicular to ice flow, but not parallel. To explain these observations, and assess the capability for range estimation, we use fabric data from the SPICE ice core to model ice birefringence and construct a bounding radio propagation model that predicts polarization time delays. We compare the model with new data from December 2018 and demonstrate that the measurements are consistent with the prevailing horizontal crystallographic axis aligned near-perpendicular to ice flow. The study supports the notion that range estimation can be performed for near flow-perpendicular trajectories, although tighter constraints on fabric orientation are desirable for improving the accuracy of estimates.

scholarly journals δD And δ18O In South Pole Snow: Further Comparison With Meteorological Data and The Record From the Last Millennium (Abstract)

1988 ◽  
Vol 11 ◽  
pp. 208
Author(s):  
J. R. Petit ◽  
J. Jouzel ◽  
J. C. White ◽  
Qian Qiu-yu ◽  
M. Legrand ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Water Cycle ◽  
Meteorological Data ◽  
Ice Core ◽  
Snow Accumulation ◽  
South Pole ◽  
The South ◽  
Isotope Record ◽  
Δd And Δ18o ◽  
Isotope Content

The stable-isotope content of precipitation (δD and δ18O) is governed by the successive fractionation processes which occur during the atmospheric water cycle. As a result there is, in polar areas, a well-obeyed and theoretically well-understood linear relationship between the mean istopic content of snow and its mean temperature of formation. This relationship is well documented on a spatial scale but poorly known for a given site on a temporal basis, the main reason being that relatively long-term and sufficiently detailed meteorological data are only available for a few polar sites. The South Pole appears to be a suitable place for such a study because: (i) snow accumulation is high enough (∼20 cm of snow per year), thus reducing the possibility that annual layers will be lost as a result of wind; (ii) seasonal variation in isotope content is still preserved in snow up to 50 years old; (iii) meteorological data are available from the time the station was opened in 1957. Our previous studies of surface and recently deposited snow at the South Pole were very encouraging in this respect; they have been extended with a two-fold purpose: (i) to test the geographical representativity of the isotope record by comparing results from various cores taken within a 10 km radius of the station. The cores are dated by various techniques, such as stratigraphy, seasonal variation in isotopic content, beta-radioactivity fall-out layers, and detection by solid conductivity measurements of the high “spike” which is thought to correspond to the 1815 Tambora eruption; (ii) to discuss the South Pole isotope record over the last 1000 years as recovered from a 127 m deep ice core.

Supplementary material to "Advection (non-climate) impact on the South Pole Ice Core"

2019 ◽  
Author(s):  
Tyler J. Fudge ◽  
David A. Lilien ◽  
Michelle Koutnik ◽  
Howard Conway ◽  
C. Max Stevens ◽  
...  
Keyword(s):  
Ice Core ◽  
Climate Impact ◽  
South Pole ◽  
The South ◽  
Supplementary Material

The South Pole ice core (SPICEcore) project

2019 ◽  
Author(s):  
Joseph Souney ◽  
Murat Aydin ◽  
Eric Steig ◽  
T. Fudge ◽  
Mark Twickler
Keyword(s):  
Ice Core ◽  
South Pole ◽  
The South

scholarly journals Parallelisms between sea surface temperature changes in the western tropical Atlantic (Guiana basin) and high latitude climate signals over the last 140 000 years

2015 ◽  
Vol 11 (2) ◽  
pp. 1143-1175 ◽  
Author(s):  
O. Rama-Corredor ◽  
B. Martrat ◽  
J. O. Grimalt ◽  
G. E. López-Otalvaro ◽  
J. A. Flores ◽  
...  
Keyword(s):  
Climate Variability ◽  
North Atlantic ◽  
Ice Core ◽  
Substantial Reduction ◽  
Unsaturation Index ◽  
Meridional Overturning Circulation ◽  
Sea Surface ◽  
Tropical Atlantic ◽  
Last Deglaciation ◽  
Temperature Changes

Abstract. Sea surface temperatures (SST) in the Guiana basin over the last 140 ka were obtained by measuring the C37 alkenone unsaturation index U37'k in sediment core MD03-2616 (7° N, 53° W). The resulting dataset is unique for this period in the western tropical Atlantic region. SSTs range from 25.1 to 28.9 °C, i.e. glacial-to-interglacial amplitude of 3.8 °C, which is common in tropical areas. During the last two interglacials (MIS1 and MIS5e) and warm long interstadials (MIS5d-a), the sediments studied trace rapid transmission of the climate variability from arctic-to-tropical latitudes and vice-versa. During these periods, MD03-2616 SSTs showed a remarkable parallelism with temperature changes observed in Greenland and SST records of North Atlantic cores. The last deglaciation in Guiana is particularly revealing. MIS2 stands out as the coldest period of the interval analysed, with SSTs reaching as low as 25.1 °C. It contains reminders of northern latitude events such as the Bølling-Allerød warming and the Younger Dryas cooling which ensued. These oscillations were previously documented in the δ18O of the Sajama tropical ice core and are present in Guiana with rates of ca. 6 °C ka−1 and changes of over 2 °C. During the glacial interval, significant abrupt variability is observed; e.g. oscillations of 0.5–1.2 °C during MIS3, i.e. about 30% of the maximum glacial–interglacial SST change. Nevertheless, in the MD03-2616 record it is hard to identify unambiguously either the Dansgaard–Oeschger type of oscillations described in northern latitudes or the SST drops associated with the Heinrich events characterising North Atlantic records. Although these specific events form the background of the climate variability observed, what truly shapes SSTs in Guiana is a long-term tropical response to precessional changes, which is modulated in the opposite way to polar variability. This lack of synchrony is consistent with other tropical records in locations to the north or south of Guiana and evidences an arctic-to-tropical decoupling when a substantial reduction in the Atlantic meridional overturning circulation (AMOC) takes place.

scholarly journals Drilling operations for the South Pole Ice Core (SPICEcore) project

2020 ◽  
pp. 1-14 ◽  
Author(s):  
Jay A. Johnson ◽  
Tanner Kuhl ◽  
Grant Boeckmann ◽  
Chris Gibson ◽  
Joshua Jetson ◽  
...  
Keyword(s):  
Ice Core ◽  
Austral Summer ◽  
South Pole ◽  
The South ◽  
University Of Wisconsin ◽  
Drilling Operations ◽  
And Performance ◽  
Core Project ◽  
The University ◽  
Drill System

Abstract Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751 m deep ice core at the South Pole. This core provided a high-resolution record of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. The drilling and core processing were completed using the new US Intermediate Depth Drill system, which was designed and built by the US Ice Drilling Program at the University of Wisconsin–Madison. In this paper, we present and discuss the setup, operation, and performance of the drill system.

scholarly journals The last deglaciation: timing the bipolar seesaw

2011 ◽  
Vol 7 (2) ◽  
pp. 671-683 ◽  
Author(s):  
J. B. Pedro ◽  
T. D. van Ommen ◽  
S. O. Rasmussen ◽  
V. I. Morgan ◽  
J. Chappellaz ◽  
...  
Keyword(s):  
Climate Changes ◽  
Ice Core ◽  
Time Lag ◽  
Last Deglaciation ◽  
Atmospheric Teleconnections ◽  
The Last Deglaciation ◽  
The Antarctic ◽  
First Time ◽  
Coupling Mechanisms ◽  
Ice Core Records

Abstract. Precise information on the relative timing of north-south climate variations is a key to resolving questions concerning the mechanisms that force and couple climate changes between the hemispheres. We present a new composite record made from five well-resolved Antarctic ice core records that robustly represents the timing of regional Antarctic climate change during the last deglaciation. Using fast variations in global methane gas concentrations as time markers, the Antarctic composite is directly compared to Greenland ice core records, allowing a detailed mapping of the inter-hemispheric sequence of climate changes. Consistent with prior studies the synchronized records show that warming (and cooling) trends in Antarctica closely match cold (and warm) periods in Greenland on millennial timescales. For the first time, we also identify a sub-millennial component to the inter-hemispheric coupling. Within the Antarctic Cold Reversal the strongest Antarctic cooling occurs during the pronounced northern warmth of the Bølling. Warming then resumes in Antarctica, potentially as early as the Intra-Allerød Cold Period, but with dating uncertainty that could place it as late as the onset of the Younger Dryas stadial. There is little-to-no time lag between climate transitions in Greenland and opposing changes in Antarctica. Our results lend support to fast acting inter-hemispheric coupling mechanisms, including recently proposed bipolar atmospheric teleconnections and/or rapid bipolar ocean teleconnections.

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