Ice streaming in the Laurentide Ice Sheet: A first comparison between data‐calibrated numerical model output and geological evidence
Ice streaming in the Laurentide Ice Sheet: A first comparison between data‐calibrated numerical model output and geological evidence
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劳伦泰冰盖中的冰流：数据校准数值模型输出与地质证据之间的首次比较
DOI：
10.1029/2009gl040990
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发表时间：
2010
影响因子：
5.2
通讯作者：
L. Tarasov
中科院分区：
文献类型：
--
作者：
C. Stokes;L. Tarasov
尽管快速流动的冰流对冰盖质量平衡的重要性，但将其纳入数值冰盖模型是一项重大的科学挑战。这在模型输出中引入了很大的不确定性，并阻碍了对冰流在整个冰盖稳定性中的作用的更完整的理解。最近的计算进步，使更现实的冰流表示，但很少有研究试图比较模型输出对已知的位置的冰流。本文比较了预测的冰流来自一个大的集合分析的冰川系统模型的劳伦特冰盖对独立的地质证据编译从以前发表的研究。虽然古冰流位置的精确定年是有问题的，但我们的分析包括冰消期间六个不同时间步长（18至10 cal ka BP）的比较。结果表明，该模型在预测所有主要的海洋终止冰流方面都是成功的，但在正确的地点和正确的时间模拟陆地冰流方面取得了混合成功，这对指导未来的模型开发至关重要。该模型还表明，虽然一些冰流坚持整个冰消的质量损失的重点与冰流开关通过时间与冰流集水区和支流的动态变化。这意味着冰流活动的重大变化，预计在冰川消融冰盖，当代冰盖动态的重要影响。
Despite the importance of rapidly‐flowing ice streams to ice sheet mass balance, their incorporation into numerical ice sheet models is a major scientific challenge. This introduces large uncertainties in model output and inhibits a more complete understanding of the role of ice streams in overall ice sheet stability. Recent computational advances have enabled more realistic representations of ice streaming but few studies have attempted to compare model output against known locations of ice streams. This paper compares predictions of ice streaming derived from a large ensemble analysis of a Glacial Systems Model of the Laurentide Ice Sheet against independent geological evidence compiled from previously published studies. Although the precise dating of paleo‐ice stream locations is problematic, our analysis includes comparisons at six different time‐steps (18 to 10 cal ka BP) during deglaciation. Results indicate that the model is successful in predicting all of the major marine‐terminating ice streams but there is mixed success in simulating terrestrial ice streams in the right place and at the right time, which is vital in guiding future model development. The model also reveals that whilst some ice streams persist throughout deglaciation the focus of mass loss associated with ice streaming switches through time with dynamic changes in ice stream catchments and tributaries. This implies that major changes in ice stream activity are to be expected in a deglaciating ice sheet, with important implications for contemporary ice sheet dynamics.
影响因子：
5.2
作者：
H. Conway;L. A. Rasmussen
通讯作者：
H. Conway;L. A. Rasmussen