Article
SAR-derived flow velocity and its link to glacier surface elevation change and mass balance Public Deposited
- Abstract
Modern remote sensing techniques, such as Synthetic Aperture Radar (SAR), can measure the direction and
intensity of glacier flow. Yet the question remains as to what these measurements reveal about glaciers’
adjustment to the warming climate. Here, we present a technique that addresses this question by linking the SARderived
velocity measurements with the glacier elevation change and the specific mass balance (i.e. mass balance
per unit area). The technique computes the speckle offset tracking results from the north, east and vertical flow
displacement time series, with the vertical component further split into a Surface Parallel Flow (SPF) advection
component due to the motion along a glacier surface slope and a non-Surface Parallel Flow (nSPF). The latter
links the glacier surface elevation change with the specific mass balance and strain rates. We apply this technique
to ascending and descending Sentinel-1 data to derive the four-dimensional flow displacement time series for
glaciers in southeast Alaska during 2016–2019. Time series extracted for a few characteristic regions demonstrate
remarkable temporal variability in flow velocities. The seasonal signal observed in the nSPF component is
modeled using the Positive Degree Day model. This method can be used for computing either mass balance or
glacier surface elevation change if one of these two parameters is known from external observations.
- Creator
- Date Issued
- 2021
- Academic Affiliation
- Journal Title
- Journal Volume
- 258
- Last Modified
- 2023-01-10
- Resource Type
- Rights Statement
- DOI
- ISSN
- 0034-4257
- Language
- License
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Sergey_Ryan_RSE.pdf | 2023-01-10 | Public | Download |