The near-surface circulation of the Nordic Seas is basically cyclonic and consists of jets and recirculation cells, which are tightly linked to the bottom topography. Variable forcing by the large-scale rotation of the wind leads to a modulation in the strength of the gyres and their interconnecting jets. This is seen in drifter and altimeter data. Currents are stronger during winter and during phases of high North Atlantic Oscillation Index. The exchanges between the North Atlantic and the Nordic Seas do not seem to be directly affected by this variable forcing. The narrow boundary currents and the intergyre jets are subject to instability, causing mesoscale current fluctuations, which contribute to the stirring and mixing of Polar and Atlantic water masses.