scholarly journals A reconstruction of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the last glacial inception

2013 ◽  
Vol 9 (6) ◽  
pp. 2507-2523 ◽  
Author(s):  
R. Schneider ◽  
J. Schmitt ◽  
P. Köhler ◽  
F. Joos ◽  
H. Fischer
Keyword(s):  
Carbon Cycle ◽  
Isotopic Composition ◽  
Stable Carbon Isotope ◽  
Carbon Isotopic Composition ◽  
Ice Cores ◽  
Glacial Maximum ◽  
Data Repository ◽  
Stable Carbon ◽  
Isotopic Data ◽  
Last Glacial

Abstract. The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (δ13Catm), as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a new record of δ13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 yr BP). The dataset is archived on the data repository PANGEA® (www.pangea.de) under 10.1594/PANGAEA.817041. The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC) and the Talos Dome ice cores in East Antarctica. We find a 0.4‰ shift to heavier values between the mean δ13Catm level in the Penultimate (~ 140 000 yr BP) and Last Glacial Maximum (~ 22 000 yr BP), which can be explained by either (i) changes in the isotopic composition or (ii) intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii) by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 yr, but with different phasing and magnitudes. Furthermore, a 5000 yr lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS5.5 (120 000 yr BP). Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

scholarly journals A high resolution record of atmospheric carbon dioxide and its stable carbon isotopic composition from the penultimate glacial maximum to the glacial inception

2013 ◽  
Vol 9 (2) ◽  
pp. 2015-2057 ◽  
Author(s):  
R. Schneider ◽  
J. Schmitt ◽  
P. Köhler ◽  
F. Joos ◽  
H. Fischer
Keyword(s):  
Carbon Cycle ◽  
Isotopic Composition ◽  
Atmospheric Carbon Dioxide ◽  
Stable Carbon Isotope ◽  
Carbon Isotopic Composition ◽  
Ice Cores ◽  
Glacial Maximum ◽  
Stable Carbon ◽  
Isotopic Data ◽  
Carbon Isotopic

Abstract. The reconstruction of the stable carbon isotope evolution in atmospheric CO2 (δ13Catm), as archived in Antarctic ice cores, bears the potential to disentangle the contributions of the different carbon cycle fluxes causing past CO2 variations. Here we present a highly resolved record of δ13Catm before, during and after the Marine Isotope Stage 5.5 (155 000 to 105 000 yr BP). The record was derived with a well established sublimation method using ice from the EPICA Dome C (EDC) and the Talos Dome ice cores in East Antarctica. We find an 0.4‰ offset between the mean δ13Catm level in the Penultimate (~140 000 yr BP) and Last Glacial Maximum (~22 000 yr BP), which can be explained by either (i) changes in the isotopic composition or (ii) intensity of the carbon input fluxes to the combined ocean/atmosphere carbon reservoir or (iii) by long-term peat buildup. Our isotopic data suggest that the carbon cycle evolution along Termination II and the subsequent interglacial was controlled by essentially the same processes as during the last 24 000 yr, but with different phasing and magnitudes. Furthermore, a 5000 yr lag in the CO2 decline relative to EDC temperatures is confirmed during the glacial inception at the end of MIS 5.5 (120 000 yr BP). Based on our isotopic data this lag can be explained by terrestrial carbon release and carbonate compensation.

PMIP-carbon: towards a multi-models comparison of climate-carbon interactions at the Last Glacial Maximum

2020 ◽  
Author(s):  
Nathaelle Bouttes ◽  
Ruza Ivanovic ◽  
Ayako Abe-Ouchi ◽  
Hidetaka Kobayashi ◽  
Laurie Menviel ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Isotopes ◽  
Last Glacial Maximum ◽  
Ocean Circulation ◽  
Ice Cores ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Intercomparison Project ◽  
The Last Glacial Maximum ◽  
The Last Glacial

<p>More and more climate models now include the carbon cycle, but multi-models studies of climate-carbon simulations within the Climate Model Intercomparison Project (CMIP) are limited to present and future time periods. In addition, the carbon cycle is not considered in the simulations of past periods analysed within the Paleoclimate Modelling Intercomparison Project (PMIP). Yet, climate-carbon interactions are crucial to anticipate future atmospheric CO<sub>2</sub> concentrations and their impact on climate. Such interactions can change depending on the background climate, it is thus necessary to compare model results among themselves and to data for past periods with different climates such as the Last Glacial Maximum (LGM).</p><p>The Last Glacial Maximum, around 21,000 years ago, was about 4°C colder than the pre-industrial, and associated with large ice sheets on the American and Eurasian continents. It is one of the best documented periods thanks to numerous paleoclimate archives such as marine sediment cores and ice cores. Despite this period having been studied for years, no consensus on the causes of the lower atmospheric CO<sub>2</sub> concentration at the time (around 180 ppm) has been reached and models still struggle to simulate these low CO<sub>2</sub> values. The ocean, which contains around 40 times more carbon than the atmosphere, likely plays a key role, but models tend to simulate ocean circulation changes in disagreement with proxy data, such as carbon isotopes.</p><p>This new project aims at comparing, for the first time, the carbon cycle representation at the Last Glacial Maximum from general circulation models and intermediate complexity models. We will explain the protocol and present first results in terms of carbon storage in the main reservoirs (atmosphere, land and ocean) and their link to key climate variables such as temperature, sea ice and ocean circulation. The use of coupled climate-carbon models will not only allow to compare changes in the carbon cycle in models and analyse their causes, but it will also enable us to better compare to indirect data related to the carbon cycle such as carbon isotopes.</p>

scholarly journals Glacial–interglacial changes in H<sub>2</sub><sup>18</sup>O, HDO and deuterium excess – results from the fully coupled ECHAM5/MPI-OM Earth system model

2016 ◽  
Vol 9 (2) ◽  
pp. 647-670 ◽  
Author(s):  
M. Werner ◽  
B. Haese ◽  
X. Xu ◽  
X. Zhang ◽  
M. Butzin ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Last Glacial Maximum ◽  
Ice Cores ◽  
Glacial Maximum ◽  
The Arctic ◽  
Spatial Gradient ◽  
Deuterium Excess ◽  
Last Glacial ◽  
Simulation Results ◽  
Fully Coupled

Abstract. In this study we present the first results of a new isotope-enabled general circulation model set-up. The model consists of the fully coupled ECHAM5/MPI-OM atmosphere–ocean model, enhanced by the JSBACH interactive land surface scheme and an explicit hydrological discharge scheme to close the global water budget. Stable water isotopes H218O and HDO have been incorporated into all relevant model components. Results of two equilibrium simulations under pre-industrial and Last Glacial Maximum conditions are analysed and compared to observational data and paleoclimate records for evaluating the model's performance in simulating spatial and temporal variations in the isotopic composition of the Earth's water cycle. For the pre-industrial climate, many aspects of the simulation results of meteoric waters are in good to very good agreement with both observations and earlier atmosphere-only simulations. The model is capable of adequately simulating the large spread in the isotopic composition of precipitation between low and high latitudes. A comparison to available ocean data also shows a good model–data agreement; however, a strong bias of overly depleted ocean surface waters is detected for the Arctic region. Simulation results under Last Glacial Maximum boundary conditions also fit to the wealth of available isotope records from polar ice cores, speleothems, as well as marine calcite data. Data–model evaluation of the isotopic composition in precipitation reveals a good match of the model results and indicates that the temporal glacial–interglacial isotope–temperature relation was substantially lower than the present spatial gradient for most mid- to high-latitudinal regions. As compared to older atmosphere-only simulations, a remarkable improvement is achieved for the modelling of the deuterium excess signal in Antarctic ice cores. Our simulation results indicate that cool sub-tropical and mid-latitudinal sea surface temperatures are key for this progress. A recently discussed revised interpretation of the deuterium excess record of Antarctic ice cores in terms of marine relative humidity changes on glacial–interglacial timescales is not supported by our model results.

The stable carbon isotopic composition of organic material in platform derived sediments: implications for reconstructing the global carbon cycle

Sedimentology ◽  
2011 ◽  
Vol 59 (1) ◽  
pp. 319-335 ◽  
Author(s):  
AMANDA M. OEHLERT ◽  
KATHRYN A. LAMB-WOZNIAK ◽  
QUINN B. DEVLIN ◽  
GRETA J. MACKENZIE ◽  
JOHN J. G. REIJMER ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Isotopic Composition ◽  
Organic Material ◽  
Carbon Isotopic Composition ◽  
Global Carbon Cycle ◽  
Stable Carbon ◽  
Carbon Isotopic ◽  
Global Carbon

scholarly journals Glacial–interglacial changes of H<sub>2</sub><sup>18</sup>O, HDO and deuterium excess – results from the fully coupled Earth System Model ECHAM5/MPI-OM

2015 ◽  
Vol 8 (10) ◽  
pp. 8835-8894 ◽  
Author(s):  
M. Werner ◽  
B. Haese ◽  
X. Xu ◽  
X. Zhang ◽  
M. Butzin ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Last Glacial Maximum ◽  
Ice Cores ◽  
Glacial Maximum ◽  
The Arctic ◽  
Spatial Gradient ◽  
Deuterium Excess ◽  
Last Glacial ◽  
Simulation Results ◽  
Fully Coupled

Abstract. In this study we present first results of a new isotope-enabled general circulation model setup. The model consists of a fully coupled atmosphere–ocean model ECHAM5/MPI-OM, enhanced by the interactive land surface scheme JSBACH and an explicit hydrological discharge scheme to close the global water budget. Stable water isotopes H218O and HDO have been incorporated into all relevant model components. Results of two equilibrium simulations under pre-industrial and last glacial maximum conditions are analysed and compared to observational data and paleoclimate records for evaluating the model's performance of simulating spatial and temporal variations in the isotopic composition of the Earth's water cycle. For the pre-industrial climate, many aspects of the simulation results of meteoric waters are in good to very good agreement with both observations and earlier atmosphere-only simulations. The model is capable of adequately simulating the large spread in the isotopic composition of precipitation between low and high latitudes. A comparison to available ocean data also shows a good model-data agreement, however a strong bias of too depleted ocean surface waters is detected for the Arctic region. Simulation results under last glacial maximum boundary conditions also fit to the wealth of available isotope records from polar ice cores, speleothems, as well as marine calcite data. Data-model evaluation of the isotopic composition in precipitation reveals a good match of the model results and indicates that the temporal glacial–interglacial isotope–temperature relation was substantially lower than the present spatial gradient for most mid- to high-latitudinal regions. As compared to older atmosphere-only simulations, a remarkable improvement is achieved for the modelling of the deuterium excess signal in Antarctic ice cores. Our simulation results indicate that cool sub-tropical and mid-latitudinal sea surface temperatures are key for this progress. A recently discussed revised interpretation of the deuterium excess record of Antarctic ice cores in terms of marine relative humidity changes on glacial–interglacial timescales is not supported by our model results.

scholarly journals Constituent elements of insoluble and non-volatile particles during the Last Glacial Maximum exhibited in the Dome Fuji (Antarctica) ice core

2009 ◽  
Vol 55 (191) ◽  
pp. 552-562 ◽  
Author(s):  
Yoshinori Iizuka ◽  
Takayuki Miyake ◽  
Motohiro Hirabayashi ◽  
Toshitaka Suzuki ◽  
Sumito Matoba ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Calcium Ion ◽  
Ice Core ◽  
Ice Cores ◽  
Glacial Maximum ◽  
Ion Concentrations ◽  
Last Glacial ◽  
Insoluble Particles ◽  
Almost All ◽  
Constituent Elements

AbstractIn order to find environmental signals based on the dust and calcium-ion concentrations in ice cores, we determine the constituent elements of residue particles obtained after melting ice samples. We have designed a sublimating system that operates at −45°C, below the eutectic temperatures of major salts. This system permits us to obtain a great many non-volatile particles. After studying the non-volatile particles, we immersed them in water to remove soluble particles and compounds. We thereby analyzed a total of 1272 residue particles (from the melted sample), 2418 non-volatile particles (after sublimation) and 1463 insoluble particles taken from five sections of Last Glacial Maximum ice from the Dome Fuji (Antarctica) ice core. Their constituent elements were determined by scanning electron microscopy/energy-dispersive X-ray spectrometry (SEM-EDS) and compared to the dust, calcium-ion and sodium-ion concentrations measured by ion chromatography. Our results indicate that >99.9% of the insoluble particles contain silicon but no sulfur, nitrogen or chlorine. A significant number of the non-volatile particles, however, contain sulfur and chlorine. We conclude that insoluble dust consists mostly of silicate, that almost all calcium ions originate from calcium sulfate and that almost all sodium ions originate from sodium sulfate and sodium chloride.

Sign in / Sign up

Export Citation Format

Share Document