Sound scattering from oceanic turbulence

Despite relatively long-standing theoretical models
for sound scattering from oceanic turbulence, many
oceanographers continue to deny its existence.
Following my dissertation work, it can no longer be
denied. Herein is the first data that unambiguously
correlates strong acoustic scatter with turbulent
temperature fluctuations in the ocean. An important
consequence of this work is that, at least under some
circumstances, it is possible to invert acoustic data
to measure turbulent dissipation rates a first step
to remotely sensing turbulent mixing. Another
consequence of this is that turbulent scatter can be
strong enough that acoustic surveys done in turbulent
areas (such as the biologically productive ocean
surface mixing layer) could be overestimating
plankton stocks by as much as an order of magnitude.
In spite of the potential for confounding the
scattering from turbulence with that from
zooplankton, zooplankton and turbulence can be
observed simultaneously with a single sounder. The
different natures of the two targets, discrete animal
targets versus volume scattering for turbulence,
allow them to be distinguished. The key is sampling
the same targets at multiple ranges.

Autorentext
Tetjana completed her Ph.D in Ocean Physics at the University of
Victoria (Canada) in

2003. After a stint as a Postdoctoral Scholar at the Woods Hole
      Oceanographic
      Institution (USA), she moved to Halifax where she now lives with her
      husband and daughter (pictured with the author). She is an
      Assistant Professor at
      Dalhousie University.

      Klappentext
      Despite relatively long-standing theoretical models for sound scattering from oceanic turbulence, many oceanographers continue to deny its existence. Following my dissertation work, it can no longer be denied. Herein is the first data that unambiguously correlates strong acoustic scatter with turbulent temperature fluctuations in the ocean. An important consequence of this work is that, at least under some circumstances, it is possible to invert acoustic data to measure turbulent dissipation rates-a first step to remotely sensing turbulent mixing. Another consequence of this is that turbulent scatter can be strong enough that acoustic surveys done in turbulent areas (such as the biologically productive ocean surface mixing layer) could be overestimating plankton stocks by as much as an order of magnitude. In spite of the potential for confounding the scattering from turbulence with that from zooplankton, zooplankton and turbulence can be observed simultaneously with a single sounder. The different natures of the two targets, discrete animal targets versus volume scattering for turbulence, allow them to be distinguished. The key is sampling the same targets at multiple ranges.