The inflow of water from the Atlantic Ocean has long been known to be an essential source of heat and salt for the Nordic Seas and the Arctic Ocean (Hansen and Osterhus 2000). However, only in the period of the projects VEINS (Variability of Exchanges in the Northern Seas) and ASOF (Arctic /Subarctic Ocean Flux Study) a coordinated effort to quantify the oceanic lateral fluxes in the Arctic/Subarctic domain has been attempted. In VEINS and ASOF, the simultaneous observation of the fluxes linking the Nordic Seas with adjacent oceans was combined with numerical modelling, providing an opportunity to synthesise the observations in a larger-scale context. In older literature on the oceanography of the Nordic Seas and the Arctic Ocean temporal variability had largely been ignored. An exception is the oceanic response to seasonally and interannually variable wind fields (e.g. Proshutinsky and Johnson 1997 and references therein). Only very few investigations have addressed variability of temperature and salinity fields due to variable fluxes at the upper boundaries or the lateral gateways. This changed dramatically in the recent decade after Quadfasel et al. (1991) had measured a significant increase of temperatures in the eastward Atlantic Water (AW) boundary current on the northern Barents Sea slope, relative to historical values. Then, it was not clear whether the observed warming was part of a long-term trend or an expression of low-frequency oscillations in the inflow water properties. © 2008 Springer Netherlands.