DOI: 10.5194/tc-11-281-2017
Scopus记录号: 2-s2.0-85011066918
论文题名: Simulating the evolution of Hardangerjøkulen ice cap in southern Norway since the mid-Holocene and its sensitivity to climate change
作者: Åkesson H ; , Nisancioglu K ; H ; , Giesen R ; H ; , Morlighem M
刊名: Cryosphere
ISSN: 19940416
出版年: 2017
卷: 11, 期: 1 起始页码: 281
结束页码: 302
语种: 英语
英文关键词: climate change
; climate forcing
; disequilibrium
; glacier dynamics
; glacier mass balance
; hypsometry
; ice cap
; ice flow
; Little Ice Age
; paleoclimate
; Pleistocene
; proxy climate record
; reconstruction
; Arctic
; Greenland
; Hardangerjokulen
; Hordaland
; Iceland
; Norway
; Patagonia
英文摘要: Understanding 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 +0.5m w.e. relative to the mass balance from the last decades almost doubles ice volume, while a decrease of 0.2 mw.e. or more induces a strong mass balance-altitude feedback and makes Hardangerjøkulen disappear entirely. Furthermore, once disappeared, an additional +0.1m 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. © Author(s) 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75612
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: Department of Earth Science, University of Bergen, Bjerknes Centre for Climate Research, Allégaten 70, Bergen, Norway; University of California, Irvine, Department of Earth System Science, 3218 Croul Hall, Irvine, CA, United States; Centre for Earth Evolution and Dynamics, University of Oslo, Po. Box 1028 Blindern, Oslo, Norway; Institute for Marine and Atmospheric Research, Utrecht University, P.O. Box 80005, TA Utrecht, Netherlands
Recommended Citation:
Åkesson H,, Nisancioglu K,H,et al. Simulating the evolution of Hardangerjøkulen ice cap in southern Norway since the mid-Holocene and its sensitivity to climate change[J]. Cryosphere,2017-01-01,11(1)