A 70-day data set from bottom-mounted ADCPs on the two sides of the Faroe-Bank Channel was analysed using the recorded flow variance and echo intensity in the deeper reaches of the passage as proxies for turbulence. A consistent picture emerged, not least since the data losses (which were ascribed to turbulence-induced activation of the fish-elimination option in the ADCP software) could be shown to co-vary with the internal M-2 tide affecting the vertical shear, which in turn proved to be correlated with the flow variance.

In a recent paper Girton et al., due to what appears to be a misunderstanding, stated that a critical-flow analysis of the deep-water transport through the Faroe Bank Channel had been undertaken by Lake et al. on the basis of rotating hydraulic theory for a channel of parabolic cross section. In fact, this quoted investigation dealt with a rectangular passage. In the present comment it is demonstrated how the use of parabolic bathymetry leads to significant improvements of the Froude number results.

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 10(6) 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.

Results from a 71-day deployment of three ADCP current meters on a section across the sill region of the Faroe Bank Channel are reported. The characteristic density structure of the channel, with warm, highly saline North Atlantic Ocean surface water overlying colder, less-saline deep water originating from the Nordic seas, lends itself well to a two-layer description of flow processes in this region. The dataset has been analyzed to describe the spatial and temporal characteristics of the deep-water potential vorticity. The most striking feature is a persistent cross-channel variation of this quantity, with higher values on the Faroe Bank side. In the 11/2-layer hydraulic calculations that were undertaken the potential vorticity was approximated as a linear distribution. The ADCP observations indicated that the deep-water flow was hydraulically controlled, and, using the direct observed transport, the analysis yielded diagnostic results for the upstream reservoir interface level that were in good agreement with observations. It was also concluded that the deviation of the potential vorticity from a constant value had no significant effects on the deep-water transport.

A review of available hydrographic data from the Faroe-Bank Channel indicates that North Icelandic/Arctic Intermediate water masses are present in the passage to a larger extent than was previously believed. The presently compiled statistics, including results on the seasonality, are discussed in relation to previous investigations. Finally, a high quality subset of the hydrographic data is used for an analysis of the alongchannel mixing of the intermediate water masses.