The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model
Since the inception of the Antarctic ice sheet at the Eocene–Oligocene transition (∼ 34 Myr ago), land ice has played a crucial role in Earth's climate. Through feedbacks in the climate system, land ice variability modifies atmospheric temperature changes induced by orbital, topographical, and...
Published in: | Climate of the Past |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2017
|
Subjects: | |
Online Access: | https://doi.org/10.5194/cp-13-1243-2017 https://www.clim-past.net/13/1243/2017/cp-13-1243-2017.pdf https://doaj.org/article/f717340895dc4c9d9ce236d3ab26c7ad |
id |
fttriple:oai:gotriple.eu:oai:doaj.org/article:f717340895dc4c9d9ce236d3ab26c7ad |
---|---|
record_format |
openpolar |
spelling |
fttriple:oai:gotriple.eu:oai:doaj.org/article:f717340895dc4c9d9ce236d3ab26c7ad 2023-05-15T13:53:58+02:00 The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model L. B. Stap R. S. W. van de Wal B. de Boer R. Bintanja L. J. Lourens 2017-09-01 https://doi.org/10.5194/cp-13-1243-2017 https://www.clim-past.net/13/1243/2017/cp-13-1243-2017.pdf https://doaj.org/article/f717340895dc4c9d9ce236d3ab26c7ad en eng Copernicus Publications doi:10.5194/cp-13-1243-2017 1814-9324 1814-9332 https://www.clim-past.net/13/1243/2017/cp-13-1243-2017.pdf https://doaj.org/article/f717340895dc4c9d9ce236d3ab26c7ad undefined Climate of the Past, Vol 13, Pp 1243-1257 (2017) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2017 fttriple https://doi.org/10.5194/cp-13-1243-2017 2023-01-22T19:25:25Z Since the inception of the Antarctic ice sheet at the Eocene–Oligocene transition (∼ 34 Myr ago), land ice has played a crucial role in Earth's climate. Through feedbacks in the climate system, land ice variability modifies atmospheric temperature changes induced by orbital, topographical, and greenhouse gas variations. Quantification of these feedbacks on long timescales has hitherto scarcely been undertaken. In this study, we use a zonally averaged energy balance climate model bidirectionally coupled to a one-dimensional ice sheet model, capturing the ice–albedo and surface–height–temperature feedbacks. Potentially important transient changes in topographic boundary conditions by tectonics and erosion are not taken into account but are briefly discussed. The relative simplicity of the coupled model allows us to perform integrations over the past 38 Myr in a fully transient fashion using a benthic oxygen isotope record as forcing to inversely simulate CO2. Firstly, we find that the results of the simulations over the past 5 Myr are dependent on whether the model run is started at 5 or 38 Myr ago. This is because the relation between CO2 and temperature is subject to hysteresis. When the climate cools from very high CO2 levels, as in the longer transient 38 Myr run, temperatures in the lower CO2 range of the past 5 Myr are higher than when the climate is initialised at low temperatures. Consequently, the modelled CO2 concentrations depend on the initial state. Taking the realistic warm initialisation into account, we come to a best estimate of CO2, temperature, ice-volume-equivalent sea level, and benthic δ18O over the past 38 Myr. Secondly, we study the influence of ice sheets on the evolution of global temperature and polar amplification by comparing runs with ice sheet–climate interaction switched on and off. By passing only albedo or surface height changes to the climate model, we can distinguish the separate effects of the ice–albedo and surface–height–temperature feedbacks. We find that ice volume ... Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Unknown Antarctic The Antarctic Climate of the Past 13 9 1243 1257 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir L. B. Stap R. S. W. van de Wal B. de Boer R. Bintanja L. J. Lourens The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
topic_facet |
geo envir |
description |
Since the inception of the Antarctic ice sheet at the Eocene–Oligocene transition (∼ 34 Myr ago), land ice has played a crucial role in Earth's climate. Through feedbacks in the climate system, land ice variability modifies atmospheric temperature changes induced by orbital, topographical, and greenhouse gas variations. Quantification of these feedbacks on long timescales has hitherto scarcely been undertaken. In this study, we use a zonally averaged energy balance climate model bidirectionally coupled to a one-dimensional ice sheet model, capturing the ice–albedo and surface–height–temperature feedbacks. Potentially important transient changes in topographic boundary conditions by tectonics and erosion are not taken into account but are briefly discussed. The relative simplicity of the coupled model allows us to perform integrations over the past 38 Myr in a fully transient fashion using a benthic oxygen isotope record as forcing to inversely simulate CO2. Firstly, we find that the results of the simulations over the past 5 Myr are dependent on whether the model run is started at 5 or 38 Myr ago. This is because the relation between CO2 and temperature is subject to hysteresis. When the climate cools from very high CO2 levels, as in the longer transient 38 Myr run, temperatures in the lower CO2 range of the past 5 Myr are higher than when the climate is initialised at low temperatures. Consequently, the modelled CO2 concentrations depend on the initial state. Taking the realistic warm initialisation into account, we come to a best estimate of CO2, temperature, ice-volume-equivalent sea level, and benthic δ18O over the past 38 Myr. Secondly, we study the influence of ice sheets on the evolution of global temperature and polar amplification by comparing runs with ice sheet–climate interaction switched on and off. By passing only albedo or surface height changes to the climate model, we can distinguish the separate effects of the ice–albedo and surface–height–temperature feedbacks. We find that ice volume ... |
format |
Article in Journal/Newspaper |
author |
L. B. Stap R. S. W. van de Wal B. de Boer R. Bintanja L. J. Lourens |
author_facet |
L. B. Stap R. S. W. van de Wal B. de Boer R. Bintanja L. J. Lourens |
author_sort |
L. B. Stap |
title |
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
title_short |
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
title_full |
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
title_fullStr |
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
title_full_unstemmed |
The influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
title_sort |
influence of ice sheets on temperature during the past 38 million years inferred from a one-dimensional ice sheet–climate model |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/cp-13-1243-2017 https://www.clim-past.net/13/1243/2017/cp-13-1243-2017.pdf https://doaj.org/article/f717340895dc4c9d9ce236d3ab26c7ad |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_source |
Climate of the Past, Vol 13, Pp 1243-1257 (2017) |
op_relation |
doi:10.5194/cp-13-1243-2017 1814-9324 1814-9332 https://www.clim-past.net/13/1243/2017/cp-13-1243-2017.pdf https://doaj.org/article/f717340895dc4c9d9ce236d3ab26c7ad |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-13-1243-2017 |
container_title |
Climate of the Past |
container_volume |
13 |
container_issue |
9 |
container_start_page |
1243 |
op_container_end_page |
1257 |
_version_ |
1766259464945532928 |