Low-Cost Expendable Buoys for Under Ice Data Collection

The NOAA Pacific Marine Environmental Laboratory (PMEL) has designed a new, low-cost, expendable under-ice buoy capable of collecting oceanographic data at the water-ice boundary to address gaps in knowledge during these critical periods. The buoys are designed to be deployed from a research vessel during the ice-free season, where they collect data while anchored to the seabed until the surface is completely covered in sea ice. At a designated time for each device, a release is triggered, which allows the buoy to ascend and be buoyant just under the ice, collecting a vertical profile of the water column during its ascent. The buoys remain at the ice-water interface collecting data, until break-up or melting of sea ice, when their data are transmitted to shore. Preliminary versions of the instrument were deployed in the Chukchi Sea in 2015 (Generation 1) and the Bering Sea in 2017 (Generation 2), collecting data on temperature, depth, and photosynthetically active radiation (PAR). These deployments successfully demonstrated the viability of the low-cost design, its robust nature, and its ability to provide high-quality data. Ongoing developments (Generation 3) include measurement of fluorescence and collection of daily images for situational awareness and to assess the presence of ice-associated algae. Onboard GPS provides precise location data from open water, and all data are transmitted to shore using Iridium Short Burst Data (Generations 2 and 3). These compact instruments are optimized for use in the relatively shallow waters of the continental shelf (up to 100 m depth) in the Bering and Chukchi seas. Their cost advantages can be best leveraged to provide improved spatial coverage over this enormous area, where observations are typically sparse. These under-ice buoys are one of several new technologies being developed as part of the Innovative Technology for Arctic Exploration (ITAE) project-a collaborative effort between scientists and engineers at NOAA and the University of Washington. Collectively, they represent a unique opportunity to improve the basic understanding of the changing Arctic environment and to cost-effectively monitor future changes.