Mending Milankovitch's theory: obliquity amplification by surface feedbacks
Milankovitch's theory states that orbitally induced changes in high-latitude summer insolation dictate the waxing and waning of ice sheets. Accordingly, precession should dominate the ice-volume response because it most strongly modulates summer insolation. However, early Pleistocene (2.588–0.7...
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ftdoajarticles:oai:doaj.org/article:60e879ed40bd46d99432bdcc9c56a65b 2023-05-15T16:40:53+02:00 Mending Milankovitch's theory: obliquity amplification by surface feedbacks C. R. Tabor C. J. Poulsen D. Pollard 2014-01-01T00:00:00Z https://doi.org/10.5194/cp-10-41-2014 https://doaj.org/article/60e879ed40bd46d99432bdcc9c56a65b EN eng Copernicus Publications http://www.clim-past.net/10/41/2014/cp-10-41-2014.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-10-41-2014 https://doaj.org/article/60e879ed40bd46d99432bdcc9c56a65b Climate of the Past, Vol 10, Iss 1, Pp 41-50 (2014) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2014 ftdoajarticles https://doi.org/10.5194/cp-10-41-2014 2022-12-31T11:21:26Z Milankovitch's theory states that orbitally induced changes in high-latitude summer insolation dictate the waxing and waning of ice sheets. Accordingly, precession should dominate the ice-volume response because it most strongly modulates summer insolation. However, early Pleistocene (2.588–0.781 Ma) ice-volume proxy records vary almost exclusively at the frequency of the obliquity cycle. To explore this paradox, we use an Earth system model coupled with a dynamic ice sheet to separate the climate responses to idealized transient orbits of obliquity and precession that maximize insolation changes. Our results show that positive surface albedo feedbacks between high-latitude annual-mean insolation, ocean heat flux and sea-ice coverage, and boreal forest/tundra exchange enhance the ice-volume response to obliquity forcing relative to precession forcing. These surface feedbacks, in combination with modulation of the precession cycle power by eccentricity, help explain the dominantly 41 kyr cycles in global ice volume of the early Pleistocene. Article in Journal/Newspaper Ice Sheet Sea ice Tundra Directory of Open Access Journals: DOAJ Articles Climate of the Past 10 1 41 50 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 C. R. Tabor C. J. Poulsen D. Pollard Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Milankovitch's theory states that orbitally induced changes in high-latitude summer insolation dictate the waxing and waning of ice sheets. Accordingly, precession should dominate the ice-volume response because it most strongly modulates summer insolation. However, early Pleistocene (2.588–0.781 Ma) ice-volume proxy records vary almost exclusively at the frequency of the obliquity cycle. To explore this paradox, we use an Earth system model coupled with a dynamic ice sheet to separate the climate responses to idealized transient orbits of obliquity and precession that maximize insolation changes. Our results show that positive surface albedo feedbacks between high-latitude annual-mean insolation, ocean heat flux and sea-ice coverage, and boreal forest/tundra exchange enhance the ice-volume response to obliquity forcing relative to precession forcing. These surface feedbacks, in combination with modulation of the precession cycle power by eccentricity, help explain the dominantly 41 kyr cycles in global ice volume of the early Pleistocene. |
format |
Article in Journal/Newspaper |
author |
C. R. Tabor C. J. Poulsen D. Pollard |
author_facet |
C. R. Tabor C. J. Poulsen D. Pollard |
author_sort |
C. R. Tabor |
title |
Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
title_short |
Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
title_full |
Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
title_fullStr |
Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
title_full_unstemmed |
Mending Milankovitch's theory: obliquity amplification by surface feedbacks |
title_sort |
mending milankovitch's theory: obliquity amplification by surface feedbacks |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/cp-10-41-2014 https://doaj.org/article/60e879ed40bd46d99432bdcc9c56a65b |
genre |
Ice Sheet Sea ice Tundra |
genre_facet |
Ice Sheet Sea ice Tundra |
op_source |
Climate of the Past, Vol 10, Iss 1, Pp 41-50 (2014) |
op_relation |
http://www.clim-past.net/10/41/2014/cp-10-41-2014.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 doi:10.5194/cp-10-41-2014 https://doaj.org/article/60e879ed40bd46d99432bdcc9c56a65b |
op_doi |
https://doi.org/10.5194/cp-10-41-2014 |
container_title |
Climate of the Past |
container_volume |
10 |
container_issue |
1 |
container_start_page |
41 |
op_container_end_page |
50 |
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1766031309351682048 |