Observations of ocean surface wave attenuation in sea ice using seafloor cables

Abstract

The attenuation of ocean surface waves during seasonal ice cover is an important control on the evolution of many Arctic coastlines. The spatial and temporal variations in this process have been challenging to resolve with conventional sampling using sparse arrays of moorings or buoys. We demonstrate a novel method for persistent observation of wave-ice interactions using distributed acoustic sensing (DAS) along existing seafloor telecommunications cables. The DAS measurements span a 36-km cross-shore seafloor cable on the Beaufort Shelf from Oliktok Point, Alaska. DAS measurements of strain-rate provide a proxy for seafloor pressure, which we calibrate with wave buoy measurements during the ice-free season (August 2022). We apply this calibration during the ice formation season (November 2021) to obtain unprecedented resolution of variable wave attenuation rates in new, partial ice cover. The location and strength of wave attenuation serve as a proxy for ice coverage and thickness, especially during rapidly-evolving events.

Observations of Ocean Surface Wave Attenuation in Sea Ice Using Seafloor Cables

“…Data sets of derived ocean surface gravity wave parameters are archived with the Arctic Data Center at https:// doi.org/10.18739/A2PK0736C (Smith et al, 2023). The DAS data recorded by the Cryosphere/Ocean Distributed Acoustic Sensing (CODAS) Experiment for the November 2021 period are archived at Open Energy Data Initiative (mhkdr.openei.org/submissions/438).…”