The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback?
Abstract Glacial–interglacial cycles constitute large natural variations in Earth’s climate. The Mid-Pleistocene Transition (MPT) marks a shift of the dominant periodicity of these climate cycles from $$\sim 40$$...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Berlin Heidelberg
2022
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| Online Access: | https://hdl.handle.net/1721.1/146170 |
| _version_ | 1811085752634703872 |
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| author | Shackleton, J. D. Follows, M. J. Thomas, P. J. Omta, A. W. |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Shackleton, J. D. Follows, M. J. Thomas, P. J. Omta, A. W. |
| author_sort | Shackleton, J. D. |
| collection | MIT |
| description | Abstract
Glacial–interglacial cycles constitute large natural variations in Earth’s climate. The Mid-Pleistocene Transition (MPT) marks a shift of the dominant periodicity of these climate cycles from
$$\sim 40$$
∼
40
to
$$\sim 100$$
∼
100
kyr. Recently, it has been suggested that this shift resulted from a gradual increase in the internal period (or equivalently, a decrease in the natural frequency) of the system. As a result, the system would then have locked to ever higher multiples of the external forcing period. We find that the internal period is sensitive to the strength of positive feedbacks in the climate system. Using a carbon cycle model in which feedbacks between calcifier populations and ocean alkalinity mediate atmospheric CO
$$_2,$$
2
,
we simulate stepwise periodicity changes similar to the MPT through such a mechanism. Due to the internal dynamics of the system, the periodicity shift occurs up to millions of years after the change in the feedback strength is imposed. This suggests that the cause for the MPT may have occurred a significant time before the observed periodicity shift. |
| first_indexed | 2024-09-23T13:14:49Z |
| format | Article |
| id | mit-1721.1/146170 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T13:14:49Z |
| publishDate | 2022 |
| publisher | Springer Berlin Heidelberg |
| record_format | dspace |
| spelling | mit-1721.1/1461702023-06-30T20:21:15Z The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? Shackleton, J. D. Follows, M. J. Thomas, P. J. Omta, A. W. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Abstract Glacial–interglacial cycles constitute large natural variations in Earth’s climate. The Mid-Pleistocene Transition (MPT) marks a shift of the dominant periodicity of these climate cycles from $$\sim 40$$ ∼ 40 to $$\sim 100$$ ∼ 100 kyr. Recently, it has been suggested that this shift resulted from a gradual increase in the internal period (or equivalently, a decrease in the natural frequency) of the system. As a result, the system would then have locked to ever higher multiples of the external forcing period. We find that the internal period is sensitive to the strength of positive feedbacks in the climate system. Using a carbon cycle model in which feedbacks between calcifier populations and ocean alkalinity mediate atmospheric CO $$_2,$$ 2 , we simulate stepwise periodicity changes similar to the MPT through such a mechanism. Due to the internal dynamics of the system, the periodicity shift occurs up to millions of years after the change in the feedback strength is imposed. This suggests that the cause for the MPT may have occurred a significant time before the observed periodicity shift. 2022-11-07T12:52:16Z 2022-11-07T12:52:16Z 2022-11-04 2022-11-06T04:14:21Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/146170 Shackleton, J. D., Follows, M. J., Thomas, P. J. and Omta, A. W. 2022. "The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback?." PUBLISHER_CC en https://doi.org/10.1007/s00382-022-06544-2 Creative Commons Attribution https://creativecommons.org/licenses/by/4.0/ The Author(s) application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg |
| spellingShingle | Shackleton, J. D. Follows, M. J. Thomas, P. J. Omta, A. W. The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title | The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title_full | The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title_fullStr | The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title_full_unstemmed | The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title_short | The Mid-Pleistocene Transition: a delayed response to an increasing positive feedback? |
| title_sort | mid pleistocene transition a delayed response to an increasing positive feedback |
| url | https://hdl.handle.net/1721.1/146170 |
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