Observing sea ice flexural-gravity waves with ground-based radar interferometry

• Main Authors: Dammann, Dyre Oliver, Johnson, Mark A., Mahoney, Andrew R., Fedders, Emily R.
• Format: Text
• Language: English
• Published: 2022
• Subjects: Sea ice; Alaska
• Online Access: https://doi.org/10.5194/tc-2022-128; https://tc.copernicus.org/preprints/tc-2022-128/

We investigate the application of ground-based radar interferometry for measuring flexural-gravity waves in sea ice. We deployed a Gamma Portable Radar Interferometer (GPRI) on top of a grounded iceberg surrounded by landfast sea ice near Utqiaġvik, Alaska. The GPRI collected 238 acquisitions in stare-mode during a period of moderate lateral ice motion during 23–24 Apr 2021. Individual 30-second interferograms exhibit ~20–50 s periodic motion indicative of propagating infragravity waves with ~1 mm amplitudes. Results include examples of onshore wave propagation at the speed predicted by the water depth and a possible edge wave along an ice discontinuity. Findings are supported through comparison with on-ice Ice Wave Rider (IWR) accelerometers and modeled wave propagation. These results suggest that the GPRI can be a valuable tool to track wave propagation through sea ice and possibly detect changes in such properties across variable ice conditions.