Cryological processes implied in Arctic proglacial stream sediment dynamics using principal components analysis and regression
Cryological processes implied in Arctic proglacial stream sediment dynamics using principal components analysis and regression
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使用主成分分析和回归揭示北极前冰河沉积物动力学中的冰冻过程
DOI：
10.1144/gsl.sp.2005.242.01.08
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
P. Mumford
中科院分区：
文献类型：
--
作者：
T. Irvine;B. Moorman;D. Sjogren;F. S. Walter;I. Willis;A. Hodson;J. L. Williams;P. Mumford
摘要在高纬度地区，最近的研究表明，热侵蚀和温度依赖性影响沉积物释放到河流系统。本文分析了三个冰川化盆地的冰前悬浮泥沙浓度（SSC）动态：冷基Austre Brøggerbreen（斯瓦尔巴），多温Midre Lovénbreen（斯瓦尔巴）和多温冰川B28（Bylot岛）。主导SSC模式的过程中的时间变化进行评估，使用逐步多元回归细分的时间序列。通过主成分和变点分析实现时间序列的划分。回归模型使用流量和替代预测变量来模拟SSC，而通过使用空气温度和辐射项作为自变量进行改进。两套模型之间的对比与对比的亚季节划分。通过对回归模型特征的解释，物理过程的时间变化隐含在时间段的过程中。数值分析表明，在SSC的河流，冰川和冰缘因子强迫响应之间的变化趋势。因此，高纬度地区冰川河流沉积物的迁移受到冰缘过程和条件的影响。这对在不断变化的环境中预测河流沉积物负荷以及利用沉积记录进行环境重建具有重要意义。
Abstract In high latitudes, recent research has demonstrated that both thermo-erosion and temperature dependence influence sediment release into fluvial systems. An analysis of proglacial suspended sediment concentration (SSC) dynamics is presented for three glacierized basins: cold-based Austre Brøggerbreen (Svalbard), polythermal Midre Lovénbreen (Svalbard) and polythermal Glacier B28 (Bylot Island). The temporal variation in processes dominating SSC patterns is assessed using stepwise multivariate regression following the subdivision of the time series. Partitioning of the time series is achieved through principal components and change point analyses. The regression models use discharge and surrogate predictor variables to model SSC, while improvements are made by using air temperature and radiation terms as independent variables. Comparisons are drawn between two sets of models with contrasting subseasonal division. By interpretation of the regression model characteristics, temporal changes in physical processes are implied over the course of the time periods. Numerical analyses suggest there is a trend for changes between fluvial, glacial and periglacial factors forcing responses in SSC. Therefore, it is conjectured that glaciofluvial sediment transfer at high latitudes is influenced by periglacial processes and conditions. This has implications for the predictions of fluvial sediment loads in a changing environment, and the use of sedimentary records for environmental reconstruction.