Seasonal Barotropic Modulation of the Deep-Water Overflow through the Faroe Bank Channel

Abstract

As a joint Nordic project, an upward-looking ADCP has been maintained at the sill of the Faroe Bank Channel from 1995 onward. Records from a period in 1998 with three current meters deployed across the channel were used to demonstrate that the Faroe Bank Channel deep-water transport from the Norwegian Sea into the North Atlantic Ocean proper can be reasonably well estimated from one centrally located ADCP. The long-term average of this transport over the period 1995?2001 was found to be 2.1 Sv (Sv ≡ 106 m?3 s?1). The transport record demonstrates a pronounced seasonality. Satellite altimetry shows that this is caused by the northbound Atlantic surface water inflow giving rise to a barotropic modulation of the deep-water flow through the Faroe?Shetland Channel and the southern reaches of the Norwegian Sea.