Estimations of the deep layers ventilation intensity in the Japan Sea
The Japan Sea waters are well-mixed below the depth of several hundred meters, both horizontally and vertically. However, judging from chlorofluorocarbons distribution, the deep waters ventilated weakly in recent decades. This situation could be explained by two possible scenarios simulated in a simple box model: i) weak and stable ventilation of the deep water since 1930s to the present, with its residence time about 500 years; ii) active ventilation of the deep water until the mid 1960s, with its residence time about 100 years, then the ventilation stopped.