Southern Ocean link between changes in atmospheric CO2 levels and northern-hemisphere climate anomalies during the last two glacial periods

Gottschalk, Julia; Skinner, Luke C; Jaccard, Samuel L.; Menviel, Laurie; Nehrbass-Ahles, Christoph; Waelbroeck, Claire

doi:10.1016/j.quascirev.2019.106067

Cited by 33 publications

(32 citation statements)

References 154 publications

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“…We found that the amplitude of atmospheric CO2 variations is well related to the NA stadial duration during MIS 6, which implies that the amplitude of CO2 variations might be affected by the duration of AMOC disruption during the early MIS 6 period . This hypothesis is also supported by a recent study using oceanic sediment cores from the Southern Ocean (Gottschalk et al, 2019b). The authors report that respired carbon levels in the deep South Atlantic decrease when AMOC is weakened during both glacial periods, and the amount of carbon loss in the deep South Atlantic is highly 10 correlated with the duration of NA stadials.…”

Section: Atmospheric Co2 Variability On Millennial Time Scalesupporting

confidence: 57%

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Shin¹,

Nehrbass-Ahles²,

Grilli³

et al. 2019

Preprint

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Abstract. Understanding natural carbon cycle/climate feedbacks on various time scales is highly relevant to reliably predict future climate changes. During the last two glacial periods, climate variations on millennial time scales were observed but the background conditions and duration of climate variations are different. Here we make use of contrasting climatic boundary conditions during the last two glacial periods to gain insight into the co-occurring carbon cycle changes. We reconstruct a new high-resolution record of atmospheric CO2 from the EPICA Dome C (EDC) ice core during Marine Isotope Stage (MIS) 6 (190 to 135 kyr BP). During long stadials in the North Atlantic (NA) region, atmospheric CO2 appears to be associated with the coeval Antarctic temperature changes at millennial time scale connected to the bipolar seesaw process. However, during one short stadial in the NA, atmospheric CO2 variation is negligible and the relationship between temperature variation in EDC and atmospheric CO2 is unclear. We suggest that the amplitude of CO2 variation may be affected by the duration of perturbations of the Atlantic Meridional Overturning Circulation (AMOC). In addition, similar to the last glacial period, in the earliest MIS 6 (MIS 6e and 6d, corresponding to 189 to 169 kyr BP), Carbon Dioxide Maxima (CDM) show different lags with respect to the corresponding abrupt CH4 jumps, the latter reflecting rapid warming in the Northern Hemisphere (NH). During MIS 6e at around 181.5 ± 0.3 kyr BP, CDM 6e.2 lags abrupt warming in the NH by only 200 ± 360 yrs. During MIS 6d which corresponds to CDM 6d.1 (171.1 ±0.2 kyr BP) and CDM 6d.2 (175.4 ± 0.4 kyr BP), the lag is much longer, i.e., 1,400 ± 375 yrs on average. The timing of CO2 variations with respect to abrupt warming in the NH may be affected by a major change in the organization of the AMOC from MIS 6e to MIS 6d.

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Section: Atmospheric Co2 Variability On Millennial Time Scalesupporting

confidence: 57%

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Shin¹,

Nehrbass-Ahles²,

Grilli³

et al. 2019

Preprint

Self Cite

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“…Proxy evidence indicates that the states of several important components of the climate-carbon cycle were not the same between MIS 3 and MIS 6. Sea ice cover in the South Atlantic was more extensive in MIS 6, and sea surface temperature in the South Atlantic is thought to have been lower (Gottschalk et al, 2020). The bipolar seesaw phenomenon has also been observed during the early MIS 6 period (Cheng et al, 2016;Jouzel et al, 2007;Margari et al, 2010).…”

Section: Introductionmentioning

confidence: 91%

“…In this equation, T diff is the temperature difference between the top and the bottom of the diffusive zone as estimated by the Goujon-Arnaud model, where surface temperature and accumulation are estimated from the stable water isotope record (Loulergue et al, 2007). (T ) is the thermal diffusion sensitivity, which has been estimated from laboratory measurements by Grachev and Severinghaus (2003).…”

Section: Gas Age Revision By Estimating ∆Depth From δ 15 Nmentioning

confidence: 99%

“…A phase difference can be observed between millennial-scale variations of temperature in the NH and SH (Northern Hemisphere and Southern Hemisphere, respectively), which is referred to as the bipolar seesaw phenomenon (Blunier and Brook, 2001;Pedro et al, 2018;Stocker and Johnsen, 2003). Potential triggers for this climatic variability on the millennial scale are fresh water perturbation in the North Atlantic (NA) or alterations of sea ice extent, surface temperature and salinity in the NA (Bond et al, 1992;Broecker et al, 1992;Heinrich, 1988;McManus et al, 1998), which may reduce the strength of the Atlantic Meridional Overturning Circulation (AMOC). This would cause a reduction in heat transport from the SH to the NH, which leads to an abrupt cooling in the NA region and a gradual warming in the SH (Stocker and Johnsen, 2003) and the opposite behavior when AMOC is strengthened.…”

Section: Introductionmentioning

confidence: 99%

“…Due to the stronger NH summer insolation, the Intertropical Convergence Zone (ITCZ) had shifted to the north, which intensified monsoon systems in low-latitude regions, such as in Asia, the Apennine Peninsula and the Levant (Ayalon et al, 2002;Bard et al, 2002;Cheng et al, 2016). This may have led to a weaker overturning circulation due to the reduction of the density of the North Atlantic surface water, making the AMOC cell shallower during MIS 6 than during MIS 3 (Gottschalk et al, 2020;Margari et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

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Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 ka)

et al. 2020

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Abstract. Using new and previously published CO2 data from the EPICA Dome C ice core (EDC), we reconstruct a new high-resolution record of atmospheric CO2 during Marine Isotope Stage (MIS) 6 (190 to 135 ka) the penultimate glacial period. Similar to the last glacial cycle, where high-resolution data already exists, our record shows that during longer North Atlantic (NA) stadials, millennial CO2 variations during MIS 6 are clearly coincident with the bipolar seesaw signal in the Antarctic temperature record. However, during one short stadial in the NA, atmospheric CO2 variation is small (∼5 ppm) and the relationship between temperature variations in EDC and atmospheric CO2 is unclear. The magnitude of CO2 increase during Carbon Dioxide Maxima (CDM) is closely related to the NA stadial duration in both MIS 6 and MIS 3 (60–27 ka). This observation implies that during the last two glacials the overall bipolar seesaw coupling of climate and atmospheric CO2 operated similarly. In addition, similar to the last glacial period, CDM during the earliest MIS 6 show different lags with respect to the corresponding abrupt CH4 rises, the latter reflecting rapid warming in the Northern Hemisphere (NH). During MIS 6i at around 181.5±0.3 ka, CDM 6i lags the abrupt warming in the NH by only 240±320 years. However, during CDM 6iv (171.1±0.2 ka) and CDM 6iii (175.4±0.4 ka) the lag is much longer: 1290±540 years on average. We speculate that the size of this lag may be related to a larger expansion of carbon-rich, southern-sourced waters into the Northern Hemisphere in MIS 6, providing a larger carbon reservoir that requires more time to be depleted.

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Ocean productivity in the Gulf of Cadiz over the last 50 kyr

Penaud¹,

Eynaud²,

Etourneau³

et al. 2021

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Southern Ocean link between changes in atmospheric CO2 levels and northern-hemisphere climate anomalies during the last two glacial periods

Cited by 33 publications

References 154 publications

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 ka)

Ocean productivity in the Gulf of Cadiz over the last 50 kyr

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Southern Ocean link between changes in atmospheric CO2 levels and northern-hemisphere climate anomalies during the last two glacial periods

Cited by 33 publications

References 154 publications

Millennial-scale atmospheric CO2 variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO2 variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO2 variations during the Marine Isotope Stage 6 period (190–135 ka)

Ocean productivity in the Gulf of Cadiz over the last 50 kyr

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Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 kyr BP)

Millennial-scale atmospheric CO₂ variations during the Marine Isotope Stage 6 period (190–135 ka)