Variability in hydrochemical properties and composition of the dense water in the Faroese Channels

Abstract

The temporal variability in deep water properties and composition in both Faroe-Shetland and Faroe Bank Channel were examined in June 2002, July 2009, and April 2015. Differences in the water column structure and property were observed between the two locations, in fluenced by difference in Atlantic inflows and by mixing processes along the channels. However, the source waters MNAW, MEIW, ISAIW, and NSDW described the deep water well at both sites at the three specified times. The seasonal shift between summer 2002/2009 and spring 2015 was traced in the surface of the water column. From available observations, the deep water in the channels experienced an increase in salinity between 2002 and 2015. The Faroe Bank warmed especially in the lightest part of the deep water in 2015 due to increased Atlantic influence at this location. Enhanced oxygen values in 2015 together with a minimal fraction of ISAIW found in the deep water composition, indicate the presence of a different source and an interchanging water supply to the channels. Source water fractions reveal no temporal variations.