2025_programme: Tracking ocean currents with an acoustic vertical line array in the Nordic Seas

Back


  • Day: June 19, Thursday
      Location / Time: A. TERPSIHORI at 15:10-15:30
  • Last minutes changes: -
  • Session: 12. Observing the Oceans Acoustically
    Organiser(s): Bruce Howe, Kay Gemba
    Chairperson(s): Bruce Howe, Kay Gemba
  • Lecture: Tracking ocean currents with an acoustic vertical line array in the Nordic Seas [Invited]
    Paper ID: 2255
    Author(s): Robert Taylor, Megan Ballard, Jason Sagers, Alejandra Sanchez-Rios, J. Thomas Ferrar, Leah Johnson, Harper Simmons
    Presenter: Robert Taylor
    Abstract: Physical oceanographic studies of water column variability are typically accomplished with direct measurements of temperature, salinity, and currents with depth. The present work suggests a reconstruction of the water column is possible using a passive acoustic vertical line array. The Northern Ocean Rapid Surface Evolution (NORSE) experiment, a multi-year study in the ice-free arctic waters near the island of Jan Mayen, provides an abundance of concurrent acoustic and oceanographic observations. Two moorings, one acoustic and one oceanographic, were deployed on a 425 m deep ridge near the Jan Mayen Channel from October 2022 to November 2023. The acoustic mooring provides 24-minute recordings collected every 4 hours on a 52 element evenly spaced (7.25 m) vertical line array sampling at 8192 Hz and spanning the majority of the water column. Acoustic estimates of water column sound speed are accomplished using the cross correlation of ambient sound between hydrophone pairs. The relatively constant salinity (~34.9 ppt) environment allows for the conversion of sound speed to temperature. Results represent the complex interactions over the ridge between the colder Jan Mayen Channel current and the warmer Norwegian Atlantic current. Further, tilt sensors placed along the acoustic mooring make it possible to reconstruct the location of the array elements over time. The shape of the array can be used to infer ocean processes including Ekman transport, tidal cycles, and strong current events. The nearby oceanographic mooring, containing temperature and salinity sensors as well as acoustic Doppler current profilers, helps to validate the work.
  • Corresponding author: Dr Robert Taylor
    Affiliation: Applied Research Laboratories: UT Austin
    Country: United States

Back