Distribution and behavior of anthropogenic I-129 in water masses ventilating the North Atlantic Ocean

Iodine 129 is released by reprocessing plants in northwestern Europe in qua ntities greatly exceeding its natural inventory and other anthropogenic sou rces. Data are presented from nine profiles of I-129 in the Greenland and N orwegian Seas and northern North Atlantic Ocean, collected during the Inter governmental Oceanographic Commission's Baseline Survey of Contaminants in the North Atlantic Ocean. Anthropogenic I-129 is evident throughout the dat a set. The distribution of I-129 in the major water masses sampled provides an excellent illustration of the unique source function of I-129, which re sults in stronger labeling of the northern-source overflow waters and the D eep Western Boundary Current of the North Atlantic Ocean than for many othe r tracers. Box models are used to explore the behavior and transport of I-1 29. These preliminary model simulations agree well with available measureme nts, pointing the way to future quantitative applications of this tracer.