UACE2023: Ocean Acoustic Tomography: A Missing Element of the Ocean Observing System

    • Session:
      Acoustic methods and technologies for ocean observatories
    • Paper:
      Ocean Acoustic Tomography: A Missing Element of the Ocean Observing System
    • Author(s):
      Brian Dushaw, John Colosi, Timothy Duda, Arata Kaneko, Hanne Sagen, Emmanuel Skarsoulis, Matthew Dzieciuch, Xiaohua Zhu
    • Abstract:
      Ocean acoustic tomography now has a long history with many observations and experiments that highlight the unique capabilities of this approach to detecting and understanding ocean variability. Examples include observations of deep mixing in the Greenland Sea, mode-1 internal tides radiating far into the ocean interior (coherent in time and space), relative vorticity on multiple scales, basin-wide and antipodal measures of temperature, barotropic currents, coastal processes in shallow water, and Arctic climate change. Despite the capabilities, tomography, and its simplified form thermometry, are not yet core observations within the Ocean Observing Systems (OOS). These observing systems could benefit greatly from applied acoustical oceanography, and both the world’s climatic circumstance and the difficulty in ocean observation argue that all available techniques should be implemented. A perception that the existence of the Argo float system obviates the need for the acoustical observations has been shown to be false; observations of ocean variability by tomography are distinct from those of floats or gliders. The growing application of acoustical measurements as part of the observing system (e.g., IQOE or underwater GPS systems) make tomography a natural addition to OOSes. The developing INTAROS system is demonstrating the integration of diverse observations, including passive and active acoustical applications, into a coherent, operational system – part of the Arctic Ocean Observing System. Within the Framework for Ocean Observing (FOO), we reiterate the recommendation of the OceanObs’99 conference and advocate a tomography system in the western North Atlantic as an initial contribution. Such a system would provide unique measurements of large-scale temperature, barotropic currents, vorticity, fluxes, and abyssal variability, while providing tracking capabilities for deep floats and gliders. This initial design, and the sustained system that would evolve from it, would result in a more complete fit-for-purpose overall observing system for essential ocean variables (EOVs) and derived quantities.
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    Contact details

    • Contact person:
      Dr Brian Dushaw
    • e-mail:
    • Affiliation:
      Nansen Environmental and Remote Sensing Center
    • Country: