Toward Long-Term Monitoring of Regional Permafrost Thaw with Satellite InSAR
Abstract. We estimate active layer thickness (ALT) for part of northern Alaska’s permafrost zone for summer 2017 to 2022 using satellite data from Sentinel-1 and ICESat-2. Interferograms were inverted using a Short Baseline Subset (SBAS) approach to estimate the amplitude of seasonal subsidence. ALT was estimated from the measured subsidence. ICESat-2 products were used to validate the InSAR displacement time-series. Most subsidence occurs between June and August in our study area. The maximum amplitude of seasonal subsidence was 2–6 cm, with ALT exceeding 1.5 m. Estimated ALT is in good agreement with in-situ and other remotely sensed data, but is sensitive to assumed thaw season onset, indicating the need for reliable surface temperature data. Our results suggest the feasibility of long-term permafrost monitoring with satellite InSAR.
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