Modeling the Controls on the Front Position of a Tidewater Glacier in Svalbard
Modeling the Controls on the Front Position of a Tidewater Glacier in Svalbard
复制标题
对斯瓦尔巴群岛潮水冰川前沿位置的控制进行建模
DOI：
10.3389/feart.2017.00029
复制
发表时间：
2017
影响因子：
2.9
通讯作者：
R. Finkelnburg
中科院分区：
文献类型：
--
作者：
J. Otero;F. Navarro;J. Lapazaran;Ethan Z. Welty;D. Puczko;R. Finkelnburg
冰裂是冰原和海洋冰川边缘重要的质量损失过程，但确定和量化其主要驱动机制仍然具有挑战性。汉斯布林是斯瓦尔巴群岛斯匹次卑尔根岛南部的一个搁浅的潮汐冰川，有着丰富的野外和遥感观测历史。现有的数据使该冰川适合评估冰裂的机制和控制，本文考虑了其中的一些。我们使用全斯托克斯热力学二维流动模型（Elmer/Ice），结合裂缝深度崩解标准，以每周时间分辨率估计汉斯布林的前沿位置。通过求解一个逆模型，每四周重新校准一次基础滑动系数。我们通过检验模型重现观测到的冰川末端前进和后退的季节性循环的能力，研究了前缘背压（混合冰浓度的函数）和充水裂缝深度可能起的作用。我们的研究结果表明，混合冰压力在冰锋的季节性进退中起着重要作用，并且在模拟的表面融水驱动下，裂缝深度崩解准则与观测到的末端位置变化非常接近。这些结果表明，潮汐冰川的行为受到海洋和大气过程的共同影响，两者都不应被忽视。
Calving is an important mass-loss process at ice sheet and marine-terminating glacier margins, but identifying and quantifying its principal driving mechanisms remains challenging. Hansbreen is a grounded tidewater glacier in southern Spitsbergen, Svalbard, with a rich history of field and remote sensing observations. The available data make this glacier suitable for evaluating mechanisms and controls on calving, some of which are considered in this paper. We use a full-Stokes thermomechanical 2D flow model (Elmer/Ice), paired with a crevasse-depth calving criterion, to estimate Hansbreen’s front position at a weekly time resolution. The basal sliding coefficient is re-calibrated every four weeks by solving an inverse model. We investigate the possible role of backpressure at the front (a function of ice melange concentration) and the depth of water filling crevasses by examining the model’s ability to reproduce the observed seasonal cycles of terminus advance and retreat. Our results suggest that the ice-melange pressure plays an important role in the seasonal advance and retreat of the ice front, and that the crevasse-depth calving criterion, when driven by modelled surface meltwater, closely replicates observed variations in terminus position. These results suggest that tidewater glacier behavior is influenced by both oceanic and atmospheric processes, and that neither of them should be ignored.
影响因子：
5.2
作者：
Cook, S.;Rutt, I. C.;James, T. D.
通讯作者：
James, T. D.
21世纪头十年斯瓦尔巴群岛的气候变化及其对Nordaustlandet Vestfonna冰盖的影响
DOI：
10.14279/depositonce-3598
发表时间：
2013
期刊：
影响因子：
--
作者：
Finkelnburg
通讯作者：
Finkelnburg