DOI: 10.5194/tc-15-407-2021
论文题名: Observing traveling waves in glaciers with remote sensing: New flexible time series methods and application to Sermeq Kujalleq (Jakobshavn Isbræ), Greenland
作者: Riel B. ; Minchew B. ; Joughin I.
刊名: Cryosphere
ISSN: 19940416
出版年: 2021
卷: 15, 期: 1 起始页码: 407
结束页码: 429
语种: 英语
英文关键词: decomposition analysis
; elevation
; glacier advance
; remote sensing
; time series analysis
; travel time
; wave field
; wave generation
; Arctic
; Greenland
; Jakobshavn Glacier
英文摘要: The recent influx of remote sensing data provides new opportunities for quantifying spatiotemporal variations in glacier surface velocity and elevation fields. Here, we introduce a flexible time series reconstruction and decomposition technique for forming continuous, time-dependent surface velocity and elevation fields from discontinuous data and partitioning these time series into short- and long-term variations. The time series reconstruction consists of a sparsity-regularized least-squares regression for modeling time series as a linear combination of generic basis functions of multiple temporal scales, allowing us to capture complex variations in the data using simple functions. We apply this method to the multitemporal evolution of Sermeq Kujalleq (Jakobshavn Isbræ), Greenland. Using 555 ice velocity maps generated by the Greenland Ice Mapping Project and covering the period 2009-2019, we show that the amplification in seasonal velocity variations in 2012-2016 was coincident with a longer-term speedup initiating in 2012. Similarly, the reduction in post-2017 seasonal velocity variations was coincident with a longer-term slowdown initiating around 2017. To understand how these perturbations propagate through the glacier, we introduce an approach for quantifying the spatially varying and frequency-dependent phase velocities and attenuation length scales of the resulting traveling waves. We hypothesize that these traveling waves are predominantly kinematic waves based on their long periods, coincident changes in surface velocity and elevation, and connection with variations in the terminus position. This ability to quantify wave propagation enables an entirely new framework for studying glacier dynamics using remote sensing data. © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164789
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; Polar Science Center Applied Physics Lab, University of Washington, Seattle, WA, United States
Recommended Citation:
Riel B.,Minchew B.,Joughin I.. Observing traveling waves in glaciers with remote sensing: New flexible time series methods and application to Sermeq Kujalleq (Jakobshavn Isbræ), Greenland[J]. Cryosphere,2021-01-01,15(1)