• Journal of Environmental Science International
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• v.4 no.2
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• pp.121-139
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• 1995

Based on the Results of Marine Meteorological and Oceanographical Observations (1966 -1987), the phenomenon of chimney is found as a candidate for the formation of the Japan Sea Proper Water (JSPW). The chimney phenomenon occurs twelve times Inuring 1966∼ 1987. The water types in the chimney denoting the deep convection are similar to those of the JSPW 0∼ 1℃ in potential temperature, 34.0∼34.1 ‰ in salinity and 68∼80 cl/t in potential thermosteric anomaly from the sea surface to the deep layer. The static stabilities in the chimney stations are unstable or neutral. This indicates that the winter time convection occurs. The JSPW sunken from the surface layer of chimney in winter spreads out under the Tsushima Warm Current area, following the isosteric surface of about 76 cl/t in Potential thermosteric anomaly. The formation of the deep water of the JSPW is mainly affected by the cooling of the sea surface than the evaporation of winds because the temperature and the salinity on the isoteric surface of about 76 cl/t in potential thermosteric anomaly ate cold and low The phenomenon of chimney occurred in here and there of the area in the north of 40" 30'N, west of 138" E. This suggests that the deep water of the JSPW is formed not in a limited area but probably in the overall region of the northern open ocean.

• Journal of Environmental Science International
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• v.3 no.4
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• pp.317-332
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• 1994

Based on the Results of Marine Meteorological and Oceanographical Observations (1966 ~ 1987), oceanographic conditions of the Japan Sea in winter was studied in relation to the Japan Sea Proper Water (JSPW). The mean and dispersion of the deep water above 1000 m depth are 0.26$\pm$0.2$^{\circ}C$ in temperature and 5.1$\pm$0.25 ml/h in oxygen. The mean and dispersion of the bottom water below 1000m depth are 0.07$\pm$$0.04^{\circ}C$ in temperature and 5.1$\pm$0.15ml/1 in oxygen. The distributions of the temperature and dissolved oxygen in the deep water above 1000m depth are ranged wider than 각one of the bottom water below 1000m depth in T-S and T-$ extrm{O}_2$ diagrams. The bottom water are showed more homogeneous and smaller variations than the deep water in the characteristics of water mass. The deep water above 1000m depth is active in contact with the atmosphere. The JSPW similar to the above characteristics is showed in the open ocean of the north of $40^{\circ}$30""N, west of $138^{\circ}$E. Therefore, the deep water is formed probably by the open-ocean convection.tion.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.27-42
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• 1993

Based on the Results of Marine Meteorological and Oceanographical Observations during 1966∼1987 and the Ten-day Marine Report during 1970∼1989 by Japan Meteorological Agency, the possible area where the Japan Sea Proper Water (JSPW) can be formed is investigated by analyzing the distribution of water types in the Japan Sea. The Japan Sea can be divided into three subareas of Northern Cold Water(NCW), Polar Front(PF) and Tsushima Warm Current (TWC) by the Polar Front identified by a 6℃ isothermal line at the sea surface in vinter. Mean position of the Polar Front is approximately parallel to the latitude 39∼40。N. The standard deviation of the Polar Front from the mean position of about 130km width is the smallest in the region between 136。E and 138。E where the Polar Front is very stable, because the branches of the Tsushima Current are converging in this region. However, standard deviations are about 180∼250km near the Korean peninsula and the Tsugaru Strait due to greater variability of warm currents. In the NCW area north of 40∼30。N and west of 138。E, the water types of the sea surface to the loom depth are similar to those of the JSPW. This fact indicates that the surface layer of the NCW area is the possible region of the JSPW formation in winter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.404-412
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• 1994

Radium isotopes were measured together with oceanographical parameters in the southern coastal region of the Korean East Sea during the period of September $2{\sim}8$, 1991. In September, there were various water masses vertically distributed in this region due to formation of strongly seasonal thermoclines. These water masses were characterized by activity of radium isotopes as well as water temperature and dissolved oxygen. Among the water masses, Japan Sea Proper Water(JSPW) below $1^{\circ}C$ had the highest Ra-226 activities but the lowest Ra-228 concentrations. However, Tsushima Surface Water (TSW) above $20^{\circ}C$ in water temperature had the highest Ra-228 which decreased sharply with depth. In TSW, Ra-228 activities were in the range of $194{\sim}270$ dpm/kl, which were approximately 10 times higher than JSPW. Activity ratios(A.R's) of Ra-228/Ra-226 were $1.9{\sim}2.6$ for TSW, $0.7{\sim}1.1$ for Tsushima Middle Water(TMW) of $12{\sim}17^{\circ}C\;to\;0.4{\sim}0.7$ for North Korea Cold Water(NKCW) with $1{\sim}7^{\circ}C$ and below 0.2 for JSPW. The Ra-228/Ra-226 ranged from 0.6 to 0.9 in the cold waters of $2{\sim}6^{\circ}C$, which were observed at depth of $65{\sim}120\;m$ in this study area. Radium isotopes provided a useful means of identifying origins of the cold water which occurred annually at intermediate or bottom layers in the southern coastal zone of the Korean East Sea. By plotting radium isotopes against water temperature, it could be observed clearly that the cold waters between $2{\sim}6^{\circ}C$ did not originate from the mixed water of JSPW and TMW but from NKCW.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.185-192
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• 1991

The vertical distribution and chemical characteristics of water masses were measured along two south-north transects in the polar front region of the central Korean East Sea. In February, a thermocline was present at depth between 50m and loom at the southern sites of a landward A-transect, and its depth was gradually deepened northward. At an outside B-transect, a thermocline was observed at significantly deep depth of 300m to 400m at two northern stations(Stn. 10 and 11), though the depth of the southward stations was nearly identical to that at the northward stations on a A-transect. In September, there were vertically more various water masses, i.e. the Tsushima Warm surface water(TWSW) or more than $20^{\circ}C$, the Tsushima Middle water(TMW) with a range of $12{\~}17^{\circ}C$, the North Korea Cold Water(NKCW) with $1{\~}7^{\circ}C$ temperature, the Japan Sea Proper Water(JSPW) of less than $1^{\circ}C$, and the mixed water. The North Korea Cold Water could be distinguishable from the other waters, especially from the mixed water of the Tsushima Middle Water and the Japan Sea Proper Water by the pattern of $T-O_2$ diagram. For instance, the North Korea Cold Water had higher oxygen by $1{\~}2ml/l$ than those in the mixed water, although both the two water masses ranged $1{\~}7^{\circ}C$ in water temperature. AOU value was the highest in the JSPW and the lowest in the TWSW. Also, AOU indicated a nearly linear and negative correlation with water temperature. However, AOU data for two masses, the NKCW and the TMW, in September departed remarkably from a regression line. Moreover, the ratio of $$\Delta P/\Delta AOU)$ in September was about $0.45{\mu}g-at/ml$ and higher than the value observed in the open sea. This high value could be elucidated by two factors; intrusion of the NKCW with high oxygen and molecular diffusion of dissolved oxygen from the surface into the lower layer. AOU would be a useful tracer for water masses in the polar front area of the Korean East Sea.