The presently available paleotemperature data implies large ice-free areas in the Greenland- Iceland-Norwegian Seas during the Last Glacial Maximum 21 600 yr BP. From these temperatures and the independent measurements of oxygen isotope ratios of fossil foraminiferal shells, glacial sea surface salinities could be computed, if the glacial relation between salinity and water isotope ratio was known. For this study, a three-dimensional numerical ocean circulation model was employed to investigate the possible shape of this still not precisely known relation, and to reconstruct a physically consistent scenario of the northern North Atlantic for the glacial summer. This scenario turned out to be quite similar to modern winter conditions, whereas the required salinity vs. oxygen isotope relation of this time must have been very different from its modern counterpart.