Observations of decay corrected tritium in the deep Eurasian Basin and Northern Fram Strait since 1979 indicate a significant decrease in 1993 whereas a box model predicts a steady decline with time. The model simulates the Greenland Sea and Eurasian Basin deep water observations reasonably closely up to the early 1990s. When it is returned to simulate the 1993 decrease in the deep Eurasian Basin Water tritium, the deep exchange between the Greenland Sea and Eurasian Basin occurs over a shorter time scale. This is likely in response to the reduced deep water formation in the Greenland Sea in the early 1980s. Modeled tritium in the deep Eurasian Basin shows the same trends as in the Greenland Sea and deep Norwegian Sea but with time lags of 8¿2 y and 17¿2 y, respectively. These lags are in close agreement with values indicated by tritium-helium3 dating. ¿ 1998 American Geophysical Union