On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets
We present results from modelling of the mid-Pliocene warm period (3.3–3 million years ago) using the Earth system model of intermediate complexity CLIMBER-2 analysing the effect of changes in boundary conditions as well as of orbital forcing on climate. First we performed equilibrium experiments fo...
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ftleibnizopen:oai:oai.leibnizopen.de:wu9q6YoBg80Wlv18UnTj 2023-10-29T02:37:07+01:00 On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets Willeit, M. Ganopolski, A. Feulner, G. 2013 application/pdf https://doi.org/10.34657/1130 https://oa.tib.eu/renate/handle/123456789/636 eng eng München : European Geopyhsical Union CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ Climate of the Past, Volume 9, Issue 4, Page 1749-1759 boundary condition carbon dioxide general circulation model ice sheet orbital forcing orography paleoclimate Pliocenere construction sea surface temperature vegetation history 550 article Text 2013 ftleibnizopen https://doi.org/10.34657/1130 2023-10-01T23:11:43Z We present results from modelling of the mid-Pliocene warm period (3.3–3 million years ago) using the Earth system model of intermediate complexity CLIMBER-2 analysing the effect of changes in boundary conditions as well as of orbital forcing on climate. First we performed equilibrium experiments following the PlioMIP (Pliocene Model Intercomparison Project) protocol with a CO2 concentration of 405 ppm, reconstructed mid-Pliocene orography and vegetation and a present-day orbital configuration. Simulated global Pliocene warming is about 2.5 °C, fully consistent with results of atmosphere–ocean general circulation model simulations performed for the same modelling setup. A factor separation analysis attributes 1.5 °C warming to CO2, 0.3 °C to orography, 0.2 °C to ice sheets and 0.4 °C to vegetation. Transient simulations for the entire mid-Pliocene warm period with time-dependent orbital forcing as well as interactive ice sheets and vegetation give a global warming varying within the range 1.9–2.8 °C. Ice sheet and vegetation feedbacks in synergy act as amplifiers of the orbital forcing, transforming seasonal insolation variations into an annual mean temperature signal. The effect of orbital forcing is more significant at high latitudes, especially during boreal summer, when the warming over land varies in the wide range from 0 to 10 °C. The modelled ice-sheet extent and vegetation distribution also show significant temporal variations. Modelled and reconstructed data for Northern Hemisphere sea-surface temperatures and vegetation distribution show the best agreement if the reconstructions are assumed to be representative for the warmest periods during the orbital cycles. This suggests that low-resolution Pliocene palaeoclimate reconstructions can reflect not only the impact of increased CO2 concentrations and topography changes but also the effect of orbital forcing. Therefore, the climate (Earth system) sensitivity estimates from Pliocene reconstructions which do not account for the effect of orbital forcing ... Article in Journal/Newspaper Ice Sheet LeibnizOpen (The Leibniz Association) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
boundary condition carbon dioxide general circulation model ice sheet orbital forcing orography paleoclimate Pliocenere construction sea surface temperature vegetation history 550 |
spellingShingle |
boundary condition carbon dioxide general circulation model ice sheet orbital forcing orography paleoclimate Pliocenere construction sea surface temperature vegetation history 550 Willeit, M. Ganopolski, A. Feulner, G. On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
topic_facet |
boundary condition carbon dioxide general circulation model ice sheet orbital forcing orography paleoclimate Pliocenere construction sea surface temperature vegetation history 550 |
description |
We present results from modelling of the mid-Pliocene warm period (3.3–3 million years ago) using the Earth system model of intermediate complexity CLIMBER-2 analysing the effect of changes in boundary conditions as well as of orbital forcing on climate. First we performed equilibrium experiments following the PlioMIP (Pliocene Model Intercomparison Project) protocol with a CO2 concentration of 405 ppm, reconstructed mid-Pliocene orography and vegetation and a present-day orbital configuration. Simulated global Pliocene warming is about 2.5 °C, fully consistent with results of atmosphere–ocean general circulation model simulations performed for the same modelling setup. A factor separation analysis attributes 1.5 °C warming to CO2, 0.3 °C to orography, 0.2 °C to ice sheets and 0.4 °C to vegetation. Transient simulations for the entire mid-Pliocene warm period with time-dependent orbital forcing as well as interactive ice sheets and vegetation give a global warming varying within the range 1.9–2.8 °C. Ice sheet and vegetation feedbacks in synergy act as amplifiers of the orbital forcing, transforming seasonal insolation variations into an annual mean temperature signal. The effect of orbital forcing is more significant at high latitudes, especially during boreal summer, when the warming over land varies in the wide range from 0 to 10 °C. The modelled ice-sheet extent and vegetation distribution also show significant temporal variations. Modelled and reconstructed data for Northern Hemisphere sea-surface temperatures and vegetation distribution show the best agreement if the reconstructions are assumed to be representative for the warmest periods during the orbital cycles. This suggests that low-resolution Pliocene palaeoclimate reconstructions can reflect not only the impact of increased CO2 concentrations and topography changes but also the effect of orbital forcing. Therefore, the climate (Earth system) sensitivity estimates from Pliocene reconstructions which do not account for the effect of orbital forcing ... |
format |
Article in Journal/Newspaper |
author |
Willeit, M. Ganopolski, A. Feulner, G. |
author_facet |
Willeit, M. Ganopolski, A. Feulner, G. |
author_sort |
Willeit, M. |
title |
On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
title_short |
On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
title_full |
On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
title_fullStr |
On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
title_full_unstemmed |
On the effect of orbital forcing on mid-Pliocene climate, vegetation and ice sheets |
title_sort |
on the effect of orbital forcing on mid-pliocene climate, vegetation and ice sheets |
publisher |
München : European Geopyhsical Union |
publishDate |
2013 |
url |
https://doi.org/10.34657/1130 https://oa.tib.eu/renate/handle/123456789/636 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Climate of the Past, Volume 9, Issue 4, Page 1749-1759 |
op_rights |
CC BY 3.0 Unported https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.34657/1130 |
_version_ |
1781061515056513024 |