Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient
Orbital forcing of the climate system is clearly shown in the Earths record of glacial–interglacial cycles, but the mechanism underlying this forcing is poorly understood. Traditional Milankovitch theory suggests that these cycles are driven by changes in high latitude summer insolation, yet this fo...
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ftinfoscience:oai:infoscience.tind.io:136673 2023-06-11T04:09:34+02:00 Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient Davis, B. A. S. Brewer, S. 2009-04-23T09:52:31Z http://infoscience.epfl.ch/record/136673 https://doi.org/10.1007/s00382-008-0480-9 https://infoscience.epfl.ch/record/136673/files/382_2008_Article_480.pdf unknown Springer-Verlag http://infoscience.epfl.ch/record/136673 doi:10.1007/s00382-008-0480-9 ISI:000262086300001 https://infoscience.epfl.ch/record/136673/files/382_2008_Article_480.pdf http://infoscience.epfl.ch/record/136673 Text 2009 ftinfoscience https://doi.org/10.1007/s00382-008-0480-9 2023-05-08T00:25:54Z Orbital forcing of the climate system is clearly shown in the Earths record of glacial–interglacial cycles, but the mechanism underlying this forcing is poorly understood. Traditional Milankovitch theory suggests that these cycles are driven by changes in high latitude summer insolation, yet this forcing is dominated by precession, and cannot account for the importance of obliquity in the Ice Age record. Here, we investigate an alternative forcing based on the latitudinal insolation gradient (LIG), which is dominated by both obliquity (in summer) and precession (in winter). The insolation gradient acts on the climate system through differential solar heating, which creates the Earths latitudinal temperature gradient (LTG) that drives the atmospheric and ocean circulation. A new pollen-based reconstruction of the LTG during the Holocene is used to demonstrate that the LTG may be much more sensitive to changes in the LIG than previously thought. From this, it is shown how LIG forcing of the LTG may help explain the propagation of orbital signatures throughout the climate system, including the Monsoon, Arctic Oscillation and ocean circulation. These relationships are validated over the last (Eemian) Interglacial, which occurred under a different orbital configuration to the Holocene. We conclude that LIG forcing of the LTG explains many criticisms of classic Milankovitch theory, while being poorly represented in climate models. Text Arctic EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) Arctic Climate Dynamics 32 2-3 143 165 |
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EPFL Infoscience (Ecole Polytechnique Fédérale Lausanne) |
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ftinfoscience |
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Orbital forcing of the climate system is clearly shown in the Earths record of glacial–interglacial cycles, but the mechanism underlying this forcing is poorly understood. Traditional Milankovitch theory suggests that these cycles are driven by changes in high latitude summer insolation, yet this forcing is dominated by precession, and cannot account for the importance of obliquity in the Ice Age record. Here, we investigate an alternative forcing based on the latitudinal insolation gradient (LIG), which is dominated by both obliquity (in summer) and precession (in winter). The insolation gradient acts on the climate system through differential solar heating, which creates the Earths latitudinal temperature gradient (LTG) that drives the atmospheric and ocean circulation. A new pollen-based reconstruction of the LTG during the Holocene is used to demonstrate that the LTG may be much more sensitive to changes in the LIG than previously thought. From this, it is shown how LIG forcing of the LTG may help explain the propagation of orbital signatures throughout the climate system, including the Monsoon, Arctic Oscillation and ocean circulation. These relationships are validated over the last (Eemian) Interglacial, which occurred under a different orbital configuration to the Holocene. We conclude that LIG forcing of the LTG explains many criticisms of classic Milankovitch theory, while being poorly represented in climate models. |
format |
Text |
author |
Davis, B. A. S. Brewer, S. |
spellingShingle |
Davis, B. A. S. Brewer, S. Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
author_facet |
Davis, B. A. S. Brewer, S. |
author_sort |
Davis, B. A. S. |
title |
Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
title_short |
Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
title_full |
Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
title_fullStr |
Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
title_full_unstemmed |
Orbital forcing and the role of the Latitudinal Temperature/Isolation Gradient |
title_sort |
orbital forcing and the role of the latitudinal temperature/isolation gradient |
publisher |
Springer-Verlag |
publishDate |
2009 |
url |
http://infoscience.epfl.ch/record/136673 https://doi.org/10.1007/s00382-008-0480-9 https://infoscience.epfl.ch/record/136673/files/382_2008_Article_480.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
http://infoscience.epfl.ch/record/136673 |
op_relation |
http://infoscience.epfl.ch/record/136673 doi:10.1007/s00382-008-0480-9 ISI:000262086300001 https://infoscience.epfl.ch/record/136673/files/382_2008_Article_480.pdf |
op_doi |
https://doi.org/10.1007/s00382-008-0480-9 |
container_title |
Climate Dynamics |
container_volume |
32 |
container_issue |
2-3 |
container_start_page |
143 |
op_container_end_page |
165 |
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1768383520916373504 |