Ice Observations and Forecasting During the Arctic Coring Project, August - September 2004

The Arctic Coring Expedition or ACEX was conducted as a special project under the Integrated Ocean Drilling Project. A review of the operational and ice management aspects of this project is provided in Keinonen et al (2006). This current paper reviews the ice observations and forecasting in more detail. Six scientists and naval architects were on board the IB Oden and Sovetskiy Soyuz to collect relevant ice data and forecast ice movement. The work involved the collection of ice data during transit and ice management, interpreting satellite imagery, ice forecasting, and providing the information to the vessels. The purpose of the project was to obtain a core from the seafloor to bed rock (420 m) on the Lomonosov Ridge, to study the paleo history of the polar cap region. This was achieved. The optimum transit route was determined using the Fengyun and Envisat satellite data which were showed the region of most leads. Once at the drill site at 88º north, Radarsat satellite data were used to identify regions of lighter ice. Ice thickness was generally 2.5 to 3.5 m, with mainly second year and old ice. Ice forecasting, using a very simple model, allowed the identification of any heavy ice expected to pass over the site and the regions where more information on ice severity was required. During the first two weeks at the drill site, the inertial oscillations of the ice were very small and not noticeable. Later the oscillations became much larger and the ice went through several complete loops, which created a minor problem for the drilling operation. Ice drift was measured by means of GPS buoys placed onto the ice and recovered by helicopter. This method worked well as the ice moved very slowly so that the buoys were within range for 2 to 3 days. A recent publication indicates that tropical conditions existed at the pole about 55 million years ago. Preliminary. Results indicated that the Polar Cap region was a shallow fresh water sea until about 15 million years ago. At that time, the region between Greenland and Norway opened, allowing the water from the Atlantic Ocean to flow north, with the result that the upper 15 million years of sediments are saline.