Temperature, salinity, nutrient, tritium, and oxygen isotope data collected during the Lomonosov Ridge Experiment along a drift track between the Makarov and Fram Basins over the Lomonosov Ridge are presented. The relationship of these quantities to the processes that maintain the halocline, in particular to the production of more saline waters by addition of brines formed during the freezing of seawater, is described. The results support the idea that the wide continental shelves of the Arctic Ocean play an important role in maintaining the halocline.