• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.171-177
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• 1982

Optical properties of sea water were studied in the western channel of the Korea Strait, based on the data obtained from fifteen oceanographic stations in July, 1980. Submarine daylight intensity was measured at intervals of 5m depth in the upper 70m layer by using the underwater irradiameter (Kahlsico $\#268_{WA}360$). The mean absorption coefficients of the sea water were shown as $0.098(0.063\sim0.183),\;0.129(0.090\sim0.270), 0.081(0.044\sim0.142),\;and 0.087(0.036\sim0,142)$ for clear, red, green, and blue color respectively. The transparency ranged from 11.5 to 24m(mean 18.3m). The mean water color in this area was $3.5(3\sim4)$ in Forel scales. The relation between absorption coefficient $(\kappa)$ and transparency (D) was $\kappa=1.72/D,\;\kappa=2.33/D,\;\kappa=1.41/D,\;and \kappa=1.44/D$ for clear, red, green, and blue color respectively. The rates of light penetration for clear, red, green, and blue color in four different depths were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were as follows; clear : $57.90\% (5m),\;23.40\%\;(15m),\;6.23\%\;(30m),\;1.00\%\;(50m).$ $red\;:\;48.95\%\;(5m),\;14,81\%\;(15m),\;2.76\%\;(30m),\;0.28\%\;(50m).$ $green:\;63.20\%\;(5m),\;30.47\%\;(15m),\;10.03\%\;(30m),\;2.24\%\;(50m).$ $blue\;:\;62.70\%\;(5m),\;30.00\%\;(15m),\;9.75\%\;(30m),\;1.70\%\;(50m)$

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.2
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• pp.119-125
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• 1987

Optical properties of sea water were studied in the Sagami Bay, Japan, based on the data obtained from six oceanographic stations in June, 1985. The observation of surface irradiance and underwater irradiance of sea water for eight kind of wavelengths (378, 422, 481, 513, 570, 621, 653, 677 nm) of sun light was conducted using the underwater irradiameter $(Isigawa\;\#\;SR-8)$. The mean attenuation coefficient of the sea water was appeared to be 0.166 $(0.061\~0.644)$ and the attenuation coefficient of the sea water for wavelength appeared such as 0.121 for 378 nm, 0.105 for 422 nm, 0.097 for 481 nm, 0.099 for 513 nm, 0.138 for 570 nm, 0.253 for 621 nm, 0.258 for 653 nm, 0.253 for 677 nm. The transparency was 12.9 m $(7.2\~18m)$, water color was $(5\~10m)$ in the study area and the sun altitude was $70.79^{\circ}\;(57.44^{\circ}\~78.42^{\circ}C)$ The relationship between attenuation coefficient (K) ana transparency (D) was $K=2.87/D(1.06/D\~5.48/D)$. The rates of light penetration for eight kind of wavelenths (378, 422, 481, 513, 570, 621, 653, 677 nm) were computed with reference to the surface light intensity respectively, The mean rate of light penetration in proportion to depths were $77.93\%\;(52.52\~94.06\%)$ in 1 m layer, $35.46\%\;(4.00\~73.64\%)$ in 5m layer, $18.71\%\;(0.24\~54.23\%)$ in 10m layer and $7.00\%\;(0.007\~27.58\%)$in 20m layer. The rate of light penetration at the transparency layer with reference to the surface light intensity was shown as $13.02\%\;(0.42\~34.78\%)$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.219-229
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• 1984

Physical and chemical survey on western channel of the Korea Strait was made using oceanographic data from July 25 to July 31, 1983. Four water types were distinguished at western channel: runoff of the Nakdong River, Tsushima Current Waters, Keoje Coastal Waters, and Ulsan Coastal Waters. Influence of the Nakdong River was greater at Southern East Coast near Yeong-Do Island in Pusan than at Keoje Coast. General characteristics of these four water types were as follows : For runoff of the Nakdong River, transparency was within 3 m, water colour chinese yellow (number 11), surface temperature $18{\sim}19^{\circ}C$, salinity less than $31\%0$, surface dissolved oxygen (D.O.) $4.5{\sim}5.0ml/l$, contents of phosphate $0.25{\sim}0.5{\mu}g-at./l$ ; these values were the highest among these four water types. For Tsushima Current waters, transparency was greater than 15 m, waters color blue (number $2{\sim}4$), surface temperature about $23^{\circ}C$, salinity $32{\sim}33\%0$, and surface D.O. greater than 5,0 ml/l. Phosphate, nitrate and silicate were less than 0.25, 2.0, and $2.5{\mu}g-at./l$, respectively; these values were the lowest among these four water types. Keoje Coastal Waters had low temperature ranging $20{\sim}21^{\circ}C$ at surface, and high salinity greater than $33\%0$. D.O. was less than 5.0 ml/l, phoshpate, $0.5{\mu}g-at./l$ nitrate and silicate were less than $3.5{\mu}g-at./l$. Ulsan Coastal Waters had the lowest surface temperature among these four types; surface temperature was less than $16^{\circ}C$, salinity greater than $33.5\%0$, and D.O., phosphate and nitrate had very high values. It seems that these high values resulted from upwelling phenomena.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.3
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• pp.234-240
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• 1986

Optical properties of sea vater were studied in Tokyo Bay, Japan, based on the data obtained from six oceanographic station in April, 1985. The observation of surface and underwater irradiances of sea water for eight kinds of wavelength (378, 422, 481, 513, 570, 621, 653, and 677 mm) of sun light was conducted using the underwater irradiameter (Isigawa ${\sharp}SR-8$). The mean attenuation coefficient of the sea water appeared to be 0.335($0.081{\sim}0.862$) and the attenuation coefficient of the sea water for each wavelength appeared as 0.268 for 378nm, 0.354 for 422nm, 0.274 for 481nm, 0.256 for 513nm, 0.284 for 570nm, 0.356 for 621nm, 0.425 for 653nm, and 0.464 for 677nm. The transparency was 5.0m ($2.5{\sim}6.5m$), water color was 10.2 ($8{\sim}14.0$) in the study area and the sun altitude was $53.62^{\circ}$ ($38.54^{\circ}{\sim}66.23^{\circ}$). The relationship between attenuation coefficient (K) and transparency (D) was K= 2.22/D ($1.30/D{\sim}3.54/D$). The rates of light penetration for eight kinds of wavelength (378, 422, 481, 513, 570, 621, 653, and 677 nm) were computed with reference to the surface light intensity each. The mean rates of light penetration in proportion to depths were $62.72\%$ ($42.23{\sim}78.43\%$) in 1 m layer, $11.91\%$ ($1.34{\sim}29.67\%$) in 5m layer, $2.64\%$ ($0.023{\sim}8.80\%$) in 10m layer, and $0.50\%$ ($0.02{\sim}3.99\%$) in 20 m layer. The rate of light penetration at the transparency layer with reference to the surface light intensity was shown as $12.51\%$ ($2.91{\sim}27.25\%$).

• 한국해양학회지
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• v.18 no.1
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• pp.55-63
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• 1983

The study on the periodic and correlation analysis between water temperature and air temperature has beenconducted by oceanographic data obtained from 1923 to 1979 (For 16-51 years) in 6 ststions in the Korean Waters. The periodic and correlation analyses has been examined by method of he Schuster's and the quadratic formula of least squares method, respectively. The results pbtained from the study are as follows; 1. Periodic analysis 1) The yearly difference between max. and mini. fo surface water temperature was 12.77-17.99$^{\circ}C$ (computed value : 11.67-16.64$^{\circ}C$) in offshore waters, and was 15.72-26.33$^{\circ}C$ (computed value : 15.13-25.29$^{\circ}C$) in inshore waters, and that of air temperature was 21.71-28.60$^{\circ}C$ (computed value : 10.50-27.22$^{\circ}C$). 2) The yearly mean of water temperature by station was 11.25-18.78$^{\circ}C$, and that of air temperature was 11.39-16.16$^{\circ}C$. 3) The annual compnent amplitrde of water temperature was 5.72-12.54$^{\circ}C$, and that of air temperature was 10.04-13.49$^{\circ}C$. 4) The semi-annual component amplitude of water temperature was 0.83-1.30$^{\circ}C$, and that of air temperature was 0.72-1.26$^{\circ}C$. 5) The annual component phase of water temperature was 215-228$^{\circ}C$ (max. temperature shall be in the first and in the middle ten days of August) in inshore waters and 138-244$^{\circ}C$ (max. temperature shall be in the first and in the middle ten days of August) in offshore waters, and that of air temperarture was 212-221$^{\circ}C$ (max. temperature shall be in the first and in the middle ten days of July and in the first tin days of August). 6) The semi-annual component phase of water temperature was 87-110$^{\circ}C$ in offshore waters, and 167-212$^{\circ}C$ in inshore waters, and that of air temperature was 156-189$^{\circ}C$. 2. Correlation analyses of water temperature and air temperature before one month. 1) When the water temperature is in rising time, the quadratic constant of correlation formual was the gradual inreasing type ( constant; 0.010-0.026) in offshore waters, and the gradual decreasing or proportional type (constant; -0.020-0.001) in inshore waters. 2) when the water temperature is in descending time, the quadratic constant of correlation formula was the gradual increasing type (constant: 0.012-0.021) 3) the determination coefficient was 0.964-0.992 at rising time and 0.982-0.999 at descending time of water temperature.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.1
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• pp.19-26
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• 2003

In order to investigate the seasonal variation of watermass in the adjacent sea of Naro Island, oceanographic observation on the fishing grounds were carried out by the training vessel of Yosu National University on winter, spring, summer, and autumn in 2000. The results obtained are summarized as follows ; 1) the watermass in the fishing ground were divided into the coastal water (30.0∼31.4psu), mixing water (31.5∼32.9psu) and the offshore water (33.0∼35.0psu) according to the distribution of salinity from T-S diagram plotted all salinity data observed on winter, spring, summer, and autumn in 2000. 2) the ranges of temperature and salinity were from 4.$3\circ_C$ to 10.1$^{\circ}C$ and from 33.1psu to 34.9psu in winter, from 8.$1\circ_C$ to 13.$7\circ_C$ and from 33.1psu to 34.3psu in spring, from 14.5$^{\circ}C$ to 24.$2\circ_C$ and from 30.5psu to 34.1psu in summer, and from 14.$5\circ_C$ to 18.$6\circ_C$ and from 30.1psu to 34.0psu in autumn, respectively. 3) the distribution of watermass in the fishing ground varied largely each seasons, but a general tendency on the distribution was obtained. That is, in winter and spring the offshore water was distributed most widely and in summer the coastal and mixing water occupied the fishing ground but in autumn the mixing water prevailed. 4) variation of temperature and salinity were appeared between the surface and 20m layer in the sea aduacent to Naro Island. Therefore, in the summer the thermocline were made between surface and 20m layer with vertical gradients of 4.$0\circ_C$/7m.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.163-177
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• 2013

An instrumented ferry made two transects per day across two current systems which are the North Korean Cold Current and the East Korean Warm Current over the years 2012-2013 from Gangneung to Ulleungdo in the southwestern East Sea. Seawater properties of these transects were measured with high spatial and temporal resolution for an extended period of time. Here the salinity records from the transects with the oceanographic observation data from East Sea Fisheries Institute of NFRDI, AVISO daily current chart and GOCI Chlorophyll-a image in 2012 and 2013 are used to study the time-series variation of salinity at the surface. The high salinity section with the range of 33.15~34.12 occurred on the transect mainly in the middle of eddy, and western boundary of strong northward current from June to October. We can found low salinity waters in both sides of the high salinity section. It is estimated that the western low salinity waters with the range of 30.58~33.20 accompanied by southward current were derived from the NKCC and the eastern waters with the range of 31.30~33.24 accompanied by northward current were derived from the Tsushima Surface Water. The lowest salinity of NKCC is confirmed in this study as 30.36. It is found that the western waters below 33.00 extended extremely toward the east about 110 km area from Gangneung and toward the south around Jukbyon coastal area as a 5~10 m layer. We can find its volume of low saline waters transport is not neglectable compared with that of Tsushima Current region in the western part of the East Sea. In this study we named it as the North Korean Low Saline Surface Water in summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.14 no.1
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• pp.1-14
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• 1978

To study the fluctuation of cold water in the East China Sea in summer heat budget of the Yellow Sea in winter was analysed based on the oceanographic and meteorological data compiled from 1951 to 1974. The maintain value of insolation was observed in December($160{\sim}190ly/day$), while the maximum in February ($250{\sim}260ly/day$). The range of the annual variation was found to be less than 50 ly/day. The value of the radiation term ($Q_s-Q_r-Q_h$) was remarkably small (mean 20 ly/day) in winter. It was negative value in December and January, and a positive value in February. The minimum total heat exchange from the sea ($Q_({h+c}$) was found value (471 ly/day) in February 1962, and the maximum (882 ly/day) in January 1963. The annual total heat exchange was minimum (588 ly/day) in 1962, and maximum (716 ly/day) in 1968. If the average deviation of mean water temperature at 50m depth layer were assumed to be the horizontal index ($C_h$) of colder water, $C_h$ is $C_h=\frac{{\Sigma}\limit_i\;A_i\;T_i}{{\Sigma}\limit_i\;A_i}$ where $A_i$ denotes the area of isothermal region and $T_i$ the value of deviation from mean sea water temperature. The vertical index ($C_v$) of cold water can be expressed similarly. Consequently the total index (C) of cold water equals to the sum of the two components, i.e. $C=C_h$＋$C_v$. Taking the deviation of mean sea surface temperature(T'w) in the third ten-day of Novembers in the Yellow Sea as the value of the initial condition, the following expressions are deduced : $C－T'w＝32.06 - 0.049$ $\;Q_T$ $C_h-T'w/2=12.20-0.019\;Q_T$ $C_v-T'w/2＝18.07-0.027\;Q_T$ where $Q_T$ denotes the total heat exchange of the sea. The correlation coefficients of these regression equations were found to be greater than 0.9. Heat budget was 588 ly/day in winter, and minimum water temperature of cold water was $18^{\circ}C$ in summer of 1962. The isotherm of $23^{\circ}C$ extended narrowly to southward up to $29^{\circ}N$ in summer. However, heat budget was 716 ly/day, and minimum water temperature of cold water was $12^{\circ}C$ in summer of 1968. The isotherm of $23^{\circ}C$ extended widely to southward up to $28^{\circ}30'N$ in summer. As a result of the present study, it may be concluded that the fluctuation of cold water of the East China Sea in summer can be predicted by the calculation of heat budget of the Yellow Sea in winter.