The water mass on the Faroe Shelf is distinct from the off-shelf water surrounding the shelf. This difference of water masses is reflected in the temperature and salinity distributions. The on-shelf water is colder and fresher than the off-shelf water throughout most of the year. A temperature/salinity front thus forms, where the on-shelf water meets the off-shelf water. The waters inside the front have a different cycle of primary production and support a different ecosystem from the off-shelf waters and they are important nursery areas for larvae of many commercially important fish stocks. Sea surface temperature measurements from the R/V Magnus Heinason in the period February 1999 to November 2000 show the existence of the front throughout the year except for a short period in autumn, and the largest cross-frontal gradients are found in the spring. Also, the measurements are used to find typical values for the frontal location and width in various directions across the shelf. The observed characteristics of the front are discussed in relation to bottom topography and proximity to a shelf edge, to the heating/cooling cycle driven by the air-sea heat flux, and to various theories for fronts generated by tidal mixing
