PI: Prof. Peter Wadhams (DAMTP)
Project Scientist: Nick Hughes

The project offers a unique opportunity for improvement of the way in which we detect and assess pressure ridge systems in sea ice. Pressure ridges are the chief obstacle to shipping in ice, and they are also the repository for up to 50% of the ice volume. They are of particular interest because their numbers and mean drafts have been diminishing rapidly in recent years (a decrease of 73%, for instance, in the number of ridges deeper than 10 m). If it were possible to map all major pressure ridge systems and find a correlation between ridge height (or draft) and a parameter retrievable from SAR, then we would be able to keep track of how pressure ridging is changing over the Arctic Basin, and of its changing contribution to total ice mass. The EU IRIS project, in which we were partners, was an approach to this ideal, and the present project enables us to correlate a new kind of SAR, at a different frequency (L-band) and higher resolution, with some real under-ice sonar profiles which give accurate drafts of all ice keels. The profiles will come from AUVs and from a new submarine operation. We will choose three critical areas for the data collection, and will use PRISM to aid in the feature identification for PALSAR. When coincident data are obtained we will seek a parameter linking SAR brightness (or a function of it) to pressure ridge height or volume.