Research Our latest project (ONR SODA) examines how the changes in the Beaufort Sea are affecting the transfer of heat, momentum and buoyancy from the atmosphere to the ocean's mixed layer. The project will measure for the full annual cycle, and we are again developing novel autonomous instruments to achieve this. We are following a two-pronged approach, developing (1) a drifting ice buoy incorporating novel high temporal- and vertical-resolution ocean measurements down to 200m, as well as meteorological sensors; and (2) the first moored upward-looking multi-beam sonars, to give a year-round 3D map of the ice underside as it drifts overhead.
Recent work has focussed on waves-in-ice and how the increasing open-water area of the summer Arctic Ocean affects the ice cover, both during the summer breakup and retreat (ONR MIZ project, 2011-2016) and during ice advance in the autumn (ONR Sea State project, 2012-2017). Both projects involved the design, construction and deployment of custom wave-measuring buoys, though in very different scenarios - one for persistent survey measurements, following air-supported deployments in the Arctic spring (MIZ) and the other for targeted process studies from the R/V Sikuliaq (Sea State).
The EU ICE-ARC project (2013-2017) continued the waves-in-ice theme, this time in the European Arctic, north of Svalbard, in collaboration with the Norwegian N-ICE 2015 programme. We are also working closely with the German Alfred Wegener Institute (AWI) to advance our understanding of characterising zooplankton with high-frequency active acoustics. We participated in four cruises of the F/S Polarstern, running our acoustics alongside AWI's LOKI optical plankton recorder.
Past research shares the goal of understanding sea ice thickness, particularly for deformed ice (ridges and rubble fields), often using autonomous underwater vehicles (AUVs) under ice. Deformed sea ice is currently poorly understood, as its characteristics (complex morphology, porosity) make it difficult to study by global methods (aka satellites). Though we have two air- and satellite-borne technologies to measure the freeboard of sea ice (laser and radar altimeters), each has its own challenges and - even if we could rely on the freeboard values obtained - we have little idea how these relate to the ice underneath the water, where most of the thickness and volume lies. Operational airborne methods (electromagentic induction), though wonderful over level ice, give poorly-understood results over deformed ice. Upward-looking sonars offer the only "truth" here, though they tend to give a very limited-area picture. Other work has studied small-scale ice dynamics, particularly for the wave-influenced method of ice formation - pancake ice. Though we studied this in the Antarctic as part of the the STiMPI project, it has found new relevance in the modern, wave-influenced, autumn Arctic too.
We gratefully acknowledge ongoing funding from the US Office of Naval Research (ONR) and the European Commission Research and Technology Directorate.