North Pacific Intermediate Water in the Northwest Pacific

북서태평양에서의 북태평양중층수

  • 양성기 (제주대학교 해양과학대학 해양토목공학과)
  • Published : 1994.09.01


By laying emphasis on the intermediate layer, water property distribution in the Northwest Pacific is studied using the hydrographic data obtained by Japan Meteorologica] Agency in the period from 1960 to 1986. The scattering of water type in T-S diagram is relatively small in the Kuroshio Region. Both the envelopes of saline side and of fresh side of the scattered data points shifts gradually from saline side to fresh side as the observation line moves from southwest to northeast. In the Mixed Water Region, the scattering of water type increases rapidly as the observation line moves north; The envelope of fresh cold side moves towards fresh cold side much faster than that of same side. The thermosteric anomaly value at the salinity minimum decreases as the observation line moves from north to south or southwest. This suggests that the water does not advect along the salinity minimum layer, but that the salinity minimun layer is understood as a boundary of two different waters aligned vertically. We defined the typical water masses for the Oyashio Water and the Kuroshio Water. The water mass below the salinity minimum layer may be created by isopycnal mixing of these two water masses with a fixed mixing rate. While, the water mass above the salinity minimum cannot be created simply by isopycnal mixing. The salinity minimum layer may be eroded from upper side due to active mixing processes in the surface layer, while the water of the salinity minimum layer moves gradually southward. This appears to give an explanation why the thermosteric anomaly value at salinity minimum decreases towards south.


  1. Oceanogr.Mag. v.42 Mixing process in the Mixed Water Region and Kuroshio Extension Regions and modification of the intermediate Kuroshio Water. Fujimura,M.;Y.Nagata,
  2. Deep-Sea Res. An Okhotsk Sea Water Anomaly: Implications for Ventilation in the North Pacific. Talley,L.D.
  3. Hydrography of the Kuroshio Extension. Kawai,H.;Stommel,;Yoshioda,
  4. J.Oceanogr.Soc.Japan. v.49 The Southward Intrusion of the Intermediate Oyashio Water along the east coast of the Boso Peninsula--Coastal Salinity-Minimun-Layer Water off the Boso Peninsula. Yang,S.-K.;Y.Nagata,;K.Taira,;M.Kawabe,
  5. J.Oceanogr.Soc.Japan. v.49 The Southward Intrusion of the Intermediate Oyashio Water along the east coast of the Boso Peninsula--Intrusion events into Sagami Bay. Yang,S.-K.;Y.Nagate,;K.Taira,;M.Kawabe,
  6. Umi to Sora v.64 The Oyashio Water system in the sea of south Hokkaido. Ishikawa,K.
  7. The Oceans -- their physics, chemistry and general biology. Sverdrup,H.U.;M.W.Johnson,;R.I.Fleming,
  8. Bull. of O.R.I. Formation of the Salinity Minimum in the Northwestern Pacific ocean. Hasunuma,K.
  9. J.Oceanogr.Soc.Japan v.47 The structure of the Kuroshio front in the vicinity of the separation point where the Kuroshio leaves Japanese Coast. Shin,H.-R.;Y.Michida,;Y.Nagata,
  10. Umi to Sora v.65 The role of the sea of Okhotsk on the formation of the Oyashio Water. Ohtani,K.
  11. Bull. Far Fish. Res. Lab. v.9 An oceanographic study of the Okhotsk sea - Particularly in regard to cold water--. Kitani,K.