동해 북구역에서의 수온과 염분의 10년 주기 변화

Abstract

Long-term variations of temperature and oxygen at intermediate depth in the northern East/Japan Sea are investigated by analyzing the historical data. Vertical profiles of temperature and oxygen are highly influenced by the existence of vertically homogeneous layer such as “mode water”. The decrease of temperature at upper layer coincides with the increase of oxygen at lower layer, which implies that the newly formed water was supplied into the intermediate depth. Temporal variations of both temperature and oxygen suggest that the large volume of the intermediate water such as the Upper Portion of the East/Japan Sea Proper Water and/or the Central Water was supplied in the late 1960’s and the mid-1980’s. It is found that both of air temperature at Vladivostok and sea surface temperature (SST) during winter were relatively cold in the 1960’s and the mid-1980’s in the northern East/Japan Sea where the water mass is believed to be formed. More detail, the overall tendency of the temporal variation of SST rather than air temperature agrees well with those of temperature and oxygen.