Development of an autonomous abyssal turbulence profiler

The National Science Foundation Division of Ocean Sciences awarded $1.477 million to the Scripps Institution of Oceanography, a division of the University of California San Diego, on September 1, 2026, to develop an autonomous abyssal turbulence profiler under the Geosciences program (CFDA 47.050).

The recipient will build an instrument capable of measuring turbulent mixing from the ocean surface to 6,000 meters depth, addressing a critical observational gap in deep-ocean science. Existing autonomous platforms measure only to intermediate depths of 2,000 meters and rely on indirect mixing inferences, leaving the abyssal ocean largely unobserved. The new microstructure-profiling float will directly measure diapycnal turbulent fluxes and buoyancy redistribution processes in the bottom boundary layer, extending measurements initiated during the Hawaii Ocean Mixing Experiment. The project supports collaboration with a commercial float manufacturer and includes training for undergraduate students through two-month summer internships and support for early-career engineers.

Work is performed in La Jolla, California. The award obligates $1.477 million through August 31, 2029. No sub-awards are planned.

Abstract

Turbulent mixing in the deep ocean is a process where swirling ocean currents blend freezing, heavy water from the bottom of the sea with lighter, slightly warmer water from above. This stirring helps distribute heat, oxygen, and nutrients that support global ocean circulation and healthy marine ecosystems. The investigators plan to build an instrument capable of measuring turbulent mixing from the surface to 6000 meters depth in the ocean. This project supports collaboration between the researcher and a commercial partner who manufactures the floats. IT also provides training for undergraduate students through 2-month summer internships and train and support several early-career engineers turbulent mixing in the deep ocean is a fundamental process that drives water-mass transformation throughout the global ocean and, therefore, controls many ocean features, such as sound speed and distributions of heat and salinity. Existing autonomous observing platforms are largely limited to intermediate depths (down to 2000M) and rely primarily on indirect inferences of mixing, leaving the abyssal ocean largely unobserved. The investigators will develop and demonstrate the first fully autonomous, full-depth (up to 6000 M) microstructure-profiling float capable of sustained abyssal bottom boundary layer (BBL) sampling, extending measurements of the vertical and horizontal decay scales of internal tide-driven turbulence made during the hawaii ocean mixing experiment. This technology will directly measure both diapycnal turbulent fluxes and the processes that redistribute buoyancy away from the BBL, addressing a critical observational GAP in deep-ocean science. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are not planned for this award.