Evidence supporting a new overflow path feeding the meridional overturning circulation through the Faroe Bank Channel

The Atlantic meridional overturning circulation conveys warm and salty Atlantic waters to higher latitudes where they cool, sink and return as dense overflow waters of Polar origin with a presumed pathway from western Nordic Seas. There are, however, a couple of modelling studies reporting that the overflow through the Faroe-Bank Channel may also be fed from the nearby Norwegian Sea along its eastern slope but no observational study has so far documented the existence of this branch. Our results based on a combination of current measurements, satellite altimetry and an eddy-resolving ocean model together reinforce the existence of this new overflow path. Furthermore, our estimates suggest that this new branch carries the major part of the overflow transport through the Faroe-Bank Channel and hence can be considered as the main source feeding the lower limb of the meridional overturning circulation in the eastern Nordic Seas. Finally, we discuss the characteristics and driving mechanisms of this new path.