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dc.contributor.authorÅkesson, Henning
dc.contributor.authorNisancioglu, Kerim H.
dc.contributor.authorMorlighem, Mathieu
dc.date.accessioned2018-03-13T08:27:39Z
dc.date.available2018-03-13T08:27:39Z
dc.date.issued2017-01-27
dc.identifier.issn1994-0424en_US
dc.identifier.issn1994-0416en_US
dc.identifier.urihttps://hdl.handle.net/1956/17508
dc.description.abstractUnderstanding of long-term dynamics of glaciers and ice caps is vital to assess their recent and future changes, yet few long-term reconstructions using ice flow models exist. Here we present simulations of the maritime Hardangerjøkulen ice cap in Norway from the mid-Holocene through the Little Ice Age (LIA) to the present day, using a numerical ice flow model combined with glacier and climate reconstructions. In our simulation, under a linear climate forcing, we find that Hardangerjøkulen grows from ice-free conditions in the mid-Holocene to its maximum extent during the LIA in a nonlinear, spatially asynchronous fashion. During its fastest stage of growth (2300–1300 BP), the ice cap triples its volume in less than 1000 years. The modeled ice cap extent and outlet glacier length changes from the LIA until today agree well with available observations. Volume and area for Hardangerjøkulen and several of its outlet glaciers vary out-of-phase for several centuries during the Holocene. This volume–area disequilibrium varies in time and from one outlet glacier to the next, illustrating that linear relations between ice extent, volume and glacier proxy records, as generally used in paleoclimatic reconstructions, have only limited validity. We also show that the present-day ice cap is highly sensitive to surface mass balance changes and that the effect of the ice cap hypsometry on the mass balance–altitude feedback is essential to this sensitivity. A mass balance shift by +0.5 m w.e. relative to the mass balance from the last decades almost doubles ice volume, while a decrease of 0.2 m w.e. or more induces a strong mass balance–altitude feedback and makes Hardangerjøkulen disappear entirely. Furthermore, once disappeared, an additional +0.1 m w.e. relative to the present mass balance is needed to regrow the ice cap to its present-day extent. We expect that other ice caps with comparable geometry in, for example, Norway, Iceland, Patagonia and peripheral Greenland may behave similarly, making them particularly vulnerable to climate change.en_US
dc.language.isoengeng
dc.publisherCopernicus Publications on behalf of the European Geosciences Unionen_US
dc.relation.ispartof<a href="http://hdl.handle.net/1956/17504" target="blank">Deglaciation of the Norwegian fjords</a>en_US
dc.rightsThis work is distributed under the Creative Commons Attribution 3.0 License.eng
dc.rights.urihttps://creativecommons.org/licenses/by/3.0/eng
dc.titleSimulating the evolution of Hardangerjøkulen ice cap in southern Norway since the mid-Holocene and its sensitivity to climate changeen_US
dc.typePeer reviewed
dc.typeJournal article
dc.description.versionpublishedVersionen_US
dc.rights.holderCopyright Author(s) 2017.en_US
dc.identifier.doihttps://doi.org/10.5194/tc-11-281-2017
dc.source.journalThe Cryosphere
dc.source.4011
dc.source.pagenumber281-302
dc.subject.nsiVDP::Matematikk og Naturvitenskap: 400::Geofag: 450en_US


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This work is distributed under the Creative Commons Attribution 3.0 License.
Med mindre annet er angitt, så er denne innførselen lisensiert som This work is distributed under the Creative Commons Attribution 3.0 License.