Articles | Volume 19, issue 4
https://doi.org/10.5194/tc-19-1621-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-19-1621-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Mapping seasonal snow melting in Karakoram using SAR and topographic data
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Lanqing Huang
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Center for Polar Observation and Modeling, University College London, London, United Kingdom
Philipp Bernhard
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Irena Hajnsek
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Microwave and Radar Institute, German Aerospace Center (DLR), Wessling, Germany
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EGUsphere, https://doi.org/10.5194/egusphere-2025-2187, https://doi.org/10.5194/egusphere-2025-2187, 2025
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Our study explores how thawing permafrost on the Qinghai-Tibet Plateau triggers landslides, mobilising stored carbon. Using satellite data from 2011 to 2020, we measured soil erosion, ice loss, and carbon mobilisation. While current impacts are modest, increasing landslide activity suggests future significance. This research underscores the need to understand permafrost thaw's role in carbon dynamics and climate change.
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EGUsphere, https://doi.org/10.5194/egusphere-2024-3474, https://doi.org/10.5194/egusphere-2024-3474, 2025
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Synthetic Aperture Radar (SAR) revealed ice features of unknown glaciological origin in southwest Greenland’s ablation zone. Using SAR techniques, we identified low-backscatter areas with surface scattering, in contrast to surrounding high-backscatter areas with scattering from the subsurface. Our first theory relates the low backscatter to residual liquid water in a weathering crust and the surrounding to bare glacier ice. These findings may deepen our understanding of ablation zone properties.
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The Cryosphere, 18, 3117–3140, https://doi.org/10.5194/tc-18-3117-2024, https://doi.org/10.5194/tc-18-3117-2024, 2024
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Interferometric synthetic aperture radar can measure the total freeboard of sea ice but can be biased when radar signals penetrate snow and ice. We develop a new method to retrieve the total freeboard and analyze the regional variation of total freeboard and roughness in the Weddell and Ross seas. We also investigate the statistical behavior of the total freeboard for diverse ice types. The findings enhance the understanding of Antarctic sea ice topography and its dynamics in a changing climate.
Marcel Stefko, Silvan Leinss, Othmar Frey, and Irena Hajnsek
The Cryosphere, 16, 2859–2879, https://doi.org/10.5194/tc-16-2859-2022, https://doi.org/10.5194/tc-16-2859-2022, 2022
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The coherent backscatter opposition effect can enhance the intensity of radar backscatter from dry snow by up to a factor of 2. Despite widespread use of radar backscatter data by snow scientists, this effect has received notably little attention. For the first time, we characterize this effect for the Earth's snow cover with bistatic radar experiments from ground and from space. We are also able to retrieve scattering and absorbing lengths of snow at Ku- and X-band frequencies.
Philipp Bernhard, Simon Zwieback, and Irena Hajnsek
The Cryosphere, 16, 2819–2835, https://doi.org/10.5194/tc-16-2819-2022, https://doi.org/10.5194/tc-16-2819-2022, 2022
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With climate change, Arctic hillslopes above ice-rich permafrost are vulnerable to enhanced carbon mobilization. In this work elevation change estimates generated from satellite observations reveal a substantial acceleration of carbon mobilization on the Taymyr Peninsula in Siberia between 2010 and 2021. The strong increase occurring in 2020 coincided with a severe Siberian heatwave and highlights that carbon mobilization can respond sharply and non-linearly to increasing temperatures.
Philipp Bernhard, Simon Zwieback, Nora Bergner, and Irena Hajnsek
The Cryosphere, 16, 1–15, https://doi.org/10.5194/tc-16-1-2022, https://doi.org/10.5194/tc-16-1-2022, 2022
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We present an investigation of retrogressive thaw slumps in 10 study sites across the Arctic. These slumps have major impacts on hydrology and ecosystems and can also reinforce climate change by the mobilization of carbon. Using time series of digital elevation models, we found that thaw slump change rates follow a specific type of distribution that is known from landslides in more temperate landscapes and that the 2D area change is strongly related to the 3D volumetric change.
Lanqing Huang, Georg Fischer, and Irena Hajnsek
The Cryosphere, 15, 5323–5344, https://doi.org/10.5194/tc-15-5323-2021, https://doi.org/10.5194/tc-15-5323-2021, 2021
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This study shows an elevation difference between the radar interferometric measurements and the optical measurements from a coordinated campaign over the snow-covered deformed sea ice in the western Weddell Sea, Antarctica. The objective is to correct the penetration bias of microwaves and to generate a precise sea ice topographic map, including the snow depth on top. Excellent performance for sea ice topographic retrieval is achieved with the proposed model and the developed retrieval scheme.
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Short summary
This work presents an improved method for seasonal wet snow mapping in Karakoram using synthetic aperture radar (SAR) data and topographic data. This method enables robust wet snow classification in complex mountainous terrain. Large-scale wet snow maps were generated using the proposed method, covering three major water basins in Karakoram over 4 years (2017–2021). Crucial snow variables were further derived from the maps and provided valuable insights on regional snow melting dynamics.
This work presents an improved method for seasonal wet snow mapping in Karakoram using synthetic...