Japan/East Sea Water Masses and Their Relation to the Sea's Circulation

The Japan/East Sea is a major anomaly in the ventilation and overturn picture of the Pacifi c Ocean. The North Pacifi c is well known to be nearly unventilated at intermediate and abyssal depths, refl ected in low oxygen concentration at 1000 m (Figure (High oxygen indicates newer water in more recent contact with the atmosphere. Oxygen declines as water "ages" after it leaves the sea surface mainly because of bacterial respiration.) Even the small production of North Pacifi c Intermediate Water in the Okhotsk Sea