Climate evolution across the Mid-Brunhes Transition
The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO 2 levels after the MBT, and benthic oxy...
Published in: | Climate of the Past |
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Main Authors: | , , , , |
Format: | Text |
Language: | English |
Published: |
2018
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Subjects: | |
Online Access: | https://doi.org/10.5194/cp-14-2071-2018 https://cp.copernicus.org/articles/14/2071/2018/ |
Summary: | The Mid-Brunhes Transition (MBT) began ∼ 430 ka with an increase in the amplitude of the 100 kyr climate cycles of the past 800 000 years. The MBT has been identified in ice-core records, which indicate interglaciations became warmer with higher atmospheric CO 2 levels after the MBT, and benthic oxygen isotope ( δ 18 O ) records, which suggest that post-MBT interglaciations had higher sea levels and warmer temperatures than pre-MBT interglaciations. It remains unclear, however, whether the MBT was a globally synchronous phenomenon that included other components of the climate system. Here, we further characterize changes in the climate system across the MBT through statistical analyses of ice-core and δ 18 O records as well as sea-surface temperature, benthic carbon isotope, and dust accumulation records. Our results demonstrate that the MBT was a global event with a significant increase in climate variance in most components of the climate system assessed here. However, our results indicate that the onset of high-amplitude variability in temperature, atmospheric CO 2 , and sea level at ∼430 ka was preceded by changes in the carbon cycle, ice sheets, and monsoon strength during Marine Isotope Stage (MIS) 14 and MIS 13. |
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