Acoustic backscatter has produced spectacular images of internal ocean processes for
nearly two decades, but interpretation of the images remains ambiguous because several
mechanisms can generate measurable backscatter. The authors present what is thought to
be the first simultaneous measurements of calibrated acoustic returns and turbulent
microstructure, collected in a set of 20-m-tall billows. The observations are from Admiralty
Inlet, a salt-stratified tidal channel near Puget Sound. Scattering due to turbulent …