Water masses and ¹²⁹I distribution in the Nordic Seas

The application of the radioactive isotope iodine-129 as a tracer of water circulation in the oceans has provided interesting information with respect to sources and mixing of different water masses. We here present results of ¹²⁹I distribution in water profiles located in the Nordic Seas and use the isotope to fingerprint water masses in the region. The samples were collected by the US research vessel Knorr in May-June 2002. ¹²⁹I signatures along the Norwegian Sea reflect a mixing of ¹²⁹I-rich surface water along the Scandinavian continental slope and ¹²⁹I-poor North Atlantic surface water. These two water masses become less segregated along the Fram Strait where apparent ¹²⁹I enrichment penetrates the return Arctic flow into the East Greenland Current. The ¹²⁹I data further suggest existence of a water mass that is not entirely labeled with respect to origin at the Denmark Strait bottom water. This water parcel probably originates from the Iceland Sea. ¹²⁹I data also shed light on the major deep water outflow from the Nordic Seas located at the Faeroe Bank Channel.