The importance of insolation changes for paleo ice sheet modeling

The growth and retreat of continental ice sheets in the past has largely been a response to changing climatic forcing. Since ablation is the principal component of mass loss for land-based ice sheets, the calculation of surface melt is an important aspect of paleo ice sheet modeling. Changes in inso...

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Main Authors: A. Robinson, H. Goelzer
Format: Article
Language:English
Published: Copernicus Publications 2014-08-01
Series:The Cryosphere
Online Access:http://www.the-cryosphere.net/8/1419/2014/tc-8-1419-2014.pdf
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author A. Robinson
H. Goelzer
author_facet A. Robinson
H. Goelzer
author_sort A. Robinson
collection DOAJ
description The growth and retreat of continental ice sheets in the past has largely been a response to changing climatic forcing. Since ablation is the principal component of mass loss for land-based ice sheets, the calculation of surface melt is an important aspect of paleo ice sheet modeling. Changes in insolation are often not accounted for in calculations of surface melt, under the assumption that the near-surface temperature transmits the majority of the climatic forcing to the ice sheet. To assess how this could affect paleo simulations, here we investigate the importance of different orbital configurations for estimating melt on the Greenland ice sheet. We find that during peak Eemian conditions, increased insolation contributes 20–50% to the surface melt anomaly. However, this percentage depends strongly on the temperature anomaly at the time. For higher temperature anomalies, the role of insolation changes is less important. This relationship is not homogenous over the ice sheet, since the contribution of insolation to melt is modulated by the local surface albedo. In coupled simulations, the additional insolation-induced melt translates into up to threefold more ice volume loss, compared to output using a model that does not account for insolation changes. We also introduce a simple correction factor that allows reduced-complexity melt models to account for changes in insolation.
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spelling doaj.art-18bc9b1419944411bc9026958ca6b77c2022-12-21T17:49:00ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242014-08-01841419142810.5194/tc-8-1419-2014The importance of insolation changes for paleo ice sheet modelingA. Robinson0H. Goelzer1Universidad Complutense de Madrid, 28040 Madrid, SpainEarth System Sciences & Department of Geography, Vrije Universiteit Brussel, Brussels, BelgiumThe growth and retreat of continental ice sheets in the past has largely been a response to changing climatic forcing. Since ablation is the principal component of mass loss for land-based ice sheets, the calculation of surface melt is an important aspect of paleo ice sheet modeling. Changes in insolation are often not accounted for in calculations of surface melt, under the assumption that the near-surface temperature transmits the majority of the climatic forcing to the ice sheet. To assess how this could affect paleo simulations, here we investigate the importance of different orbital configurations for estimating melt on the Greenland ice sheet. We find that during peak Eemian conditions, increased insolation contributes 20–50% to the surface melt anomaly. However, this percentage depends strongly on the temperature anomaly at the time. For higher temperature anomalies, the role of insolation changes is less important. This relationship is not homogenous over the ice sheet, since the contribution of insolation to melt is modulated by the local surface albedo. In coupled simulations, the additional insolation-induced melt translates into up to threefold more ice volume loss, compared to output using a model that does not account for insolation changes. We also introduce a simple correction factor that allows reduced-complexity melt models to account for changes in insolation.http://www.the-cryosphere.net/8/1419/2014/tc-8-1419-2014.pdf
spellingShingle A. Robinson
H. Goelzer
The importance of insolation changes for paleo ice sheet modeling
The Cryosphere
title The importance of insolation changes for paleo ice sheet modeling
title_full The importance of insolation changes for paleo ice sheet modeling
title_fullStr The importance of insolation changes for paleo ice sheet modeling
title_full_unstemmed The importance of insolation changes for paleo ice sheet modeling
title_short The importance of insolation changes for paleo ice sheet modeling
title_sort importance of insolation changes for paleo ice sheet modeling
url http://www.the-cryosphere.net/8/1419/2014/tc-8-1419-2014.pdf
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