The PIs are proposing the development of a diamond-coated polysilicon thermistor with a spatial resolution of 0.1 mm, temporal resolution of 0.1 ms, and the strength required for deployment at full ocean depths. The sensor will be constructed using a semiconductor fabrication process, using a 0.5 micrometer layer of polysilicon as the sensor, and a thin layer of diamond coating to insulate the polysilicon from seawater. Measurement of ocean temperature to very small space and time scales is necessary to determine mixing rates, and to understand turbulence and air-sea exchange processes. However, current thermometer technology possesses neither the spatial nor the temporal resolution to make the necessary measurements from existing platforms, nor is it sufficiently robust. The combination of these properties will provide a robust thermometer that has unprecedented resolution and will allow ocean studies at scales that have been heretofore unachievable. Two areas of application provide motivation: studies of the boundary layer at the air-sea interface, and studies of turbulence and mixing in the ocean interior. Quantification of ocean mixing is carried out by direct measurements of, the rate of diffusive smoothing of temperature fluctuations. Implementation of the proposed sensor on the Air-Sea Interaction Profiler and the High Resolution Profiler will respectively allow routine detection of the interfacial boundary layer, and enhance measurement abilities for oceanic dissipation at all depths. In addition, the PIs anticipate other applications in higher speed towed and autonomous instruments that will enable expanded measurement capabilities for a variety of mixing and air-sea exchange studies.
Broader Impacts
If successful, a fast, robust, quite and relatively inexpensive sensor would be a significant advancement over currently-available sensors, and could see broad usage in studies of ocean mixing, air-sea interaction, climate. Many investigators want to measure and understand the ocean temperature profile near the sea surface. The PI's express a commitment to finding a company that will make the sensor commercially available to the community.
