Spatial and Temporal Variations in 94-GHz Radar Backscatter From a Springtime Snowpack
Terrestrial snow cover is a perennial feature of the mountain cryosphere and can change rapidly in response to variable weather patterns. Measuring the interaction between atmospheric conditions and a snowpack at high spatial and temporal resolution requires the use of close-range sensors. Here, we...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IEEE
2025-01-01
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| Series: | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/10816080/ |
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| Summary: | Terrestrial snow cover is a perennial feature of the mountain cryosphere and can change rapidly in response to variable weather patterns. Measuring the interaction between atmospheric conditions and a snowpack at high spatial and temporal resolution requires the use of close-range sensors. Here, we measured the variability of a spring snowpack across two corries in Scotland using ground-based 94 GHz radar in order to assess its ability to monitor snowpack changes. We deployed both the second generation All-weather Volcano Topography Imaging Sensor (AVTIS2) 94 GHz radar and a Riegl LPM-321 Terrestrial Laser Scanner in the Cairngorms National Park, Scotland, in March 2021 over 3 days. AVTIS2 is a tripod-mounted, real-aperture radar system which mechanically scans across a scene of interest to map normalized radar cross section <inline-formula><tex-math notation="LaTeX">$(\sigma ^{0})$</tex-math></inline-formula> and 3-D point clouds. We measured an increase in <inline-formula><tex-math notation="LaTeX">$\sigma ^{0}$</tex-math></inline-formula> of <inline-formula><tex-math notation="LaTeX">$\sim$</tex-math></inline-formula>10 dB over 24 h during which time the daytime (09:00–18:00) average air temperature reduced from 2.2 to 0.3 <inline-formula><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C. We suggest this increase in radar backscatter was due to the transition of the snowpack from surface melting to a refrozen state. Overnight, snow drift led to the formation of windslab across the headwall of the corrie and subsequent snowpack failure, which we identified through a localized increase in <inline-formula><tex-math notation="LaTeX">$\sigma ^{0}$</tex-math></inline-formula> of 10–15 dB. The high sensitivity of 94-GHz radar backscatter to changes in snow surface conditions demonstrates the capabilities of millimeter-wave radar for daily monitoring of snow cover characteristics across complex topography with a spatial resolution of approximately a few meters. |
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| ISSN: | 1939-1404 2151-1535 |