Evolution of Backscattering Coefficients of Drifting Multi-Year Sea Ice during End of Melting and Onset of Freeze-up in the Western Beaufort Sea

• Published in: Remote Sensing
• Main Authors: Seung Hee Kim, Hyun-Cheol Kim, Chang-Uk Hyun, Sungjae Lee, Jung-Seok Ha, Joo-Hong Kim, Young-Joo Kwon, Jeong-Won Park, Hyangsun Han, Seong-Yeob Jeong, Duk-jin Kim
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2020
• Subjects: sea ice; synthetic aperture radar; multi-year; arctic; Beaufort Sea; backscattering coefficient; incidence angle; Arctic; Arctic Ocean; Sea ice
• Online Access: https://doi.org/10.3390/rs12091378

Backscattering coefficients of Sentinel-1 synthetic aperture radar (SAR) data of drifting multi-year sea ice in the western Beaufort Sea during the transition period between the end of melting and onset of freeze-up are analyzed, in terms of the incidence angle dependence and temporal variation. The mobile sea ice surface is tracked down in a 1 km by 1 km region centered at a GPS tracker, which was installed during a field campaign in August 2019. A total of 24 Sentinel-1 images spanning 17 days are used and the incidence angle dependence in HH- and HV-polarization are −0.24 dB/deg and −0.10 dB/deg, respectively. Hummocks and recently frozen melt ponds seem to cause the mixture behavior of surface and volume scattering. The normalized backscattering coefficients in HH polarization gradually increased in time at a rate of 0.15 dB/day, whereas the HV-polarization was relatively flat. The air temperature from the ERA5 hourly reanalysis data has a strong negative relation with the increasing trend of the normalized backscattering coefficients in HH-polarization. The result of this study is expected to complement other previous studies which focused on winter or summer seasons in other regions of the Arctic Ocean.