Systems Analysis of complex glaciological processes and application to calving of Amery Ice Shelf, East Antarctica
Systems Analysis of complex glaciological processes and application to calving of Amery Ice Shelf, East Antarctica
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DOI：
10.1017/aog.2017.1
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发表时间：
2017-04
影响因子：
2.9
通讯作者：
Michael Chester;B. Kulessa;A. Luckman;J. Bassis;P. K. Munneke
中科院分区：
文献类型：
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作者：
Michael Chester;B. Kulessa;A. Luckman;J. Bassis;P. K. Munneke
产犊是一个复杂的过程，受大气、海洋和冰川等多种相互作用的强迫作用的影响，这些强迫作用在空间和时间上各不相同，其相对影响难以区分。统计“系统分析”通常用于工程和经济学中，以摆脱复杂的“力-响应”关系。在这里，我们应用系统分析，埃默里裂谷系统，东南极洲。我们开发了一个可扩展的“系统模型”，由偏远地区冰川观测的粗采样数据集驱动，并使用2000-06年和2012年观察到的裂谷长度对其进行验证。在这个初步的演示中，我们预测了大型平板冰山的分离日期为2019年± 5年，俗称“松牙”，相对湿度令人惊讶地成为最好的统计预测因子。RACMO 2气候模型显示，相对湿度与地表积雪和融雪的相关性最好，这两者都与积雪压实和冰架温度和流动密切相关。因此，我们假设相对湿度可以作为内应力的代表，这是“松动牙齿”产犊的已知关键控制因素。虽然系统分析中没有隐含物理因果关系，但这样的假设可以帮助确定复杂冰川过程研究的优先顺序。
ABSTRACT Calving is a complex process subject to several cooperating atmospheric, oceanographic and glaciological forcings that vary in space and time, and whose relative effects are challenging to separate. Statistical ‘Systems Analysis’ is commonly used in engineering and economics to extricate complex ‘force–response’ relationships. Here we apply Systems Analysis to the Amery rift system, East Antarctica. We develop a scalable ‘System Model’ driven by a coarsely-sampled dataset characteristic of glaciological observations in remote locations, and validate it using rift lengths observed in 2000–06 and 2012. In this initial demonstration, we forecast a detachment date of ~2019 ± 5 years for the large tabular iceberg colloquially known as the ‘Loose Tooth’, for which relative humidity surprisingly emerges as the best statistical predictor. RACMO2 climate modelling reveals that relative humidity correlates best with surface albedo and snowmelt, both of which are intimately linked to firn compaction and ice shelf temperature and flow. We postulate that relative humidity can therefore serve as a proxy for internal stress, a known key control of ‘Loose Tooth’ calving. Although no physical causality is implied in Systems Analysis, postulates such as this can aid in setting priorities in studies of complex glaciological processes.