Observations of exponential wave attenuation in Antarctic sea ice during the PIPERS campaign

• Published in: Annals of Glaciology
• Main Authors: Alison L. Kohout, Madison Smith, Lettie A. Roach, Guy Williams, Fabien Montiel, Michael J. M. Williams
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2020
• Subjects: Sea ice; sea-ice dynamics; sea-ice growth and decay; Meteorology. Climatology; QC851-999; Antarctic; The Antarctic; Ross Sea; Pancake; Annals of Glaciology; Antarc*
• Online Access: https://doi.org/10.1017/aog.2020.36; https://doaj.org/article/7863f69c8edf4e169d75dbdec3c1df4c

Quantifying the rate of wave attenuation in sea ice is key to understanding trends in the Antarctic marginal ice zone extent. However, a paucity of observations of waves in sea ice limits progress on this front. We deployed 14 waves-in-ice observation systems (WIIOS) on Antarctic sea ice during the Polynyas, Ice Production, and seasonal Evolution in the Ross Sea expedition (PIPERS) in 2017. The WIIOS provide in situ measurement of surface wave characteristics. Two experiments were conducted, one while the ship was inbound and one outbound. The sea ice throughout the experiments generally consisted of pancake and young ice <0.5 m thick. The WIIOS survived a minimum of 4 d and a maximum of 6 weeks. Several large-wave events were captured, with the largest recorded significant wave height over 9 m. We find that the total wave energy measured by the WIIOS generally decays exponentially in the ice and the rate of decay depends on ice concentration.