Award: OCE-1635466

This project constructed a free-falling autonomous instrument to collect oceanographic data and seawater samples over the full range of ocean depths (from 0 to 11 km below sealevel). The Deep Autonomous Profiler (DAP) system is equipped with conductivity, temperature, depth and oxygen sensors. The DAP also operates both conventional Niskin-type water-sampling bottles and specialized high-pressure-retaining water samplers, each of which can be triggered by the onboard computer at prescribed and adaptively calculated depths. For adaptive sampling the system processes data collected during the downcast when it reaches the seafloor and then determines the depths where samples should be collected on the upcast. The system was tested off the New England Shelf Break and then during several cruises to the Puerto Rico Trench. The DAP was able to create deep hydrographic profiles and collect water samples at features within the water column. Water collected from the trench was dated as the oldest samples collected in the Atlantic Ocean, aged at approximately 320 years. The DAP system is now fully functional and can be operated at sea with one or two technicians. It was recently used on a deep coring cruise and for night operations during an ALVIN cruise as a auxiliary system. This project supported a graduate student who completed a MS degree related to the vehicle?s design and the results from the initial sea trials were published in the Journal of Oceanic Technology. Last Modified: 09/29/2022 Submitted by: Christopher Roman