WATER MASSES AND CIRCULATION IN THE EURASIAN BASIN - RESULTS FROM THEODEN 91 EXPEDITION

The Oden 91 North Pole expedition obtained oceanographic measurements on four sections in the Nansen and Amundsen basins of the Eurasian Bas in and in the Makarov Basin of the Canadian Basin, thereby proving the feasibility of carrying out a typical oceanographic program using an icebreaker in the Arctic Ocean. The data show greater spatial variabil ity in water structure and circulation than was apparent from previous data. The results show that a clear front exists between the Eurasian and Canadian basins such that upper halocline water in the Canadian B asin is almost absent from the Eurasian Basin. The lower halocline wat er produced in the Barents-Kara Sea region permeates much of the Euras ian Basin and flows along the continental slope into the Canadian Basi n. The deeper circulation is strongly influenced by topography. Three return flows of the Atlantic layer are identified, one over the Nansen -Gakkel Ridge, one over the Lomonosov Ridge, and a third flowing from the Canadian Basin. The slight differences observed in salinity and te mperature characteristics of the deeper waters of the Nansen and Amund sen basins do not lead to an obvious explanation of their origin or fl ow pattern.