• Journal of the Korean Society of Marine Environment & Safety
• /
• v.5 no.1
• /
• pp.19-27
• /
• 1999

This paper is to estimate the long and short term variations of mean sea level in Korean coastal waters by identifying interrelations among the mean sea level, atmospheric pressure and air temperature along the coast. For this, long-term tidal data observed at tidal and weather observation stations were brought into a statistical analysis. It was noted that, in a general sense, an inverse relationship exists between the sea level and the atmospheric pressure and a positive relationship between the sea level and air temperature, respectively. The maximum difference of monthly mean sea level was in the range of 21 to 25 cm at the eastern and southeastern coasts, meanwhile more than 30 cm being in both in southern and western coasts. It was also noted that mean sea level continues to rise in a long-term basis. Long-term variation of mean sea level trends to rise 0.10 ∼ 0.44 cm per year for each region. However, the long-term variation of mean sea level in the isolated islands shows a different trend, Ullngdo being 0.41 cm fall per year and Chejudo being 0.44 cm rise per year.

• 한국해양학회지
• /
• v.12 no.2
• /
• pp.67-74
• /
• 1977

With the serial observation data and the tidal records at Busan and Izuhara from 1966 to 1973, the geostrophic current velocity and its relation to the difference of mean sea level of both sides were studied in order to estimate indirectly the average current velocity from the tidal observations. The results shows that the current velocity is estimated by the relationship V=4.016(H-98.3) with the 95% confidence limits of V 4.2 cm/sec. Ther relationship between the observed current velocity and the simultaneous daily mean sea level difference shows a similar result, V=4.717(H-99.6). The two equations were applied to the evaluation of annual variations of current velocity from the average monthly mean sea level data of both stations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.10a
• /
• pp.300-303
• /
• 2001

The first 7 years of altimeter data from the TOPEX/POSEIDON (T/P) were analyzed to study the surface circulation and its variability in the East Asian Marginal Seas. Long term averaged T/P sea level time series data where compared with in situ sea level measurements from a float-operated type tide gauge around of south Korea and Japan. T/P data are a large contaminated by 60-day tidal aliasing effect, very near the alias periods of M2 and S2. When this 60-day effect is removed, the data agree well with the tide gauge data with 4.6 cm averaged RMS difference. The T/P derived sea level variability reveals clearly the well-known, strong current-topography such as Kuroshio. The T/P mean sea level of North Pacific (NP) was higher than Yellow Sea (YS) and East Sea (ES). The T/P sea level valibility, with strong eddy and meandaring, was the largest in eastern part of Japan and this variability was mainly due to the influence of bottom topography in Kuroshio Extention area.

• Journal of Environmental Science International
• /
• v.9 no.1
• /
• pp.19-25
• /
• 2000

As the tideland reclamation is done on a large scale these days, construction work is active in the coastal areas. Facilities in the coastal areas must be built with the tide characteristics taken into consideration. Thus the tide characteristics affect the overall reclamation plan. The analysis of the tide data boils down to a harmonic analysis of the hourly changes of long-term tide data and extraction of unharmonic coefficients from the results. Since considerable amount of tide data of the West Coast are available, the existing data can be collected and can be used to obtain the temporal changes of the tide by being fitted into the tide prediction model. The goal of this thesis lies in assessing whether the mean sea level used in the field agrees with the analysis results from the long-term observation data obtained with their homogeneity guaranteed. To achieve this goal, the research was conducted as follows. First the present conditions of the observation stations, the land level standard, and the sea level standard were analyzed to set up a time series model formula for representing them. To secure the homogeneity of the time series, each component was separated. Lastly the mean sea level used in the field was assessed based on the results obtained form the analysis of the time series.

• 한국해양학회지
• /
• v.14 no.2
• /
• pp.45-53
• /
• 1979

The barometric factor is estimated at five stations in the Bay of Biscay from the linear regression between daily mean sea level and atmospheric pressure. The results show that the adjusted sea level change is important in amplitude in spite of the barometric response of the sea level to the atmospheric pressure. The cross-correlations between adjusted sea levels and the two components of wind stress suggest that the adjusted sea level is highly related to the longshore wind stress. The observed phase and the time lag between adjusted sea levels at adjacent stations aree consistent with the hypothesis of the northward travelling continental shelf waves.

• Ocean and Polar Research
• /
• v.24 no.2
• /
• pp.147-152
• /
• 2002

Seasonal and interannual variation of volume transport through the La-Perouse Strait were estimated using the difference of sea level observed at Krillion of Sakhalin, Russia, and Wakkanai of Hokkaido, Japan, during the period of 1975-1988. Historical sea level measurements between Russian and Japanese tide gauge data were normalized using an independent direct volume transport measurement. Volume transport from the East Sea (Sea of Japan) to the Sea of Okhotsk varied from -0.01 to 1.18 Sv with an annual mean value of 0.61 Sv. Monthly water transport rates showed a unimodal distribution with its maximum occurring in summer (August) and minimum in winter (December-February). The annual mean volume transport varied from 0.2 to 0.8 Sv during the period of 1975-1988 with the maximum variance of 0.6 Sv.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.26 no.3
• /
• pp.120-130
• /
• 2014

Change of mean sea level in the western coast of Korean peninsula was estimated with the observed tide data of the KHOA. The cause of the change was investigated. Mean sea levels in the western coast have been changed due to coastal development projects in the coastal zone. The estimated variations, which are significantly different regionally, vary from -6.8 cm in Incheon to 38 cm in Gunsan. The changing rate of mean sea level occurred by natural factors such as global warming varies from 1.1 mm/year in the north to 4.4 mm/year in the south of western coast of Korean peninsula. In Jeju, sea level rise and rise of sea temperature showed a close relationship. Water temperature rise of one degree increases mean sea level to 0.6 mm in Jeju. Rising rate of mean sea level has increased rapidly after the mid-1980s.

• Journal of the korean society of oceanography
• /
• v.32 no.4
• /
• pp.171-180
• /
• 1997

Daily mean sea level variability and its response to atmospheric pressure along the coasts of the northwestern Pacific Ocean are investigated. Daily values of sea level and atmospheric pressure covering the period 1976-1986 from 72 stations are analyzed. The sea level and the air pressure in all the data set have a definite seasonal signal, and higher frequency oscillations at time scales of several days to several weeks are also observed. Among the short-period oscillations of sea level with periods shorter than six months, the period of around 3 or 4 months is dominant in most study stations. According to the statistical analysis of sea level and air pressure, the length scale of sea level variability is smaller than that of air pressure for the present study area. The overall variability of sea level is found to be the smallest around Hokkaido, Japan and the largest in the China coasts. Large short-period (< 6 months) sea level variability is found in the southern coasts of China and Hokkaido, and large long-period (> 6 months) variability in the southern coasts of Japan and Korea along Tsushima Current and Kuroshio. The patterns of air pressure are very similar to those of sea level. The air pressure field is found to account for 31% of the overall sea level variability in the study area. Conside.ins the fact that the results (40%) of Pang and Oh (1995) were obtained through monthly sea level, the present result implies that the short-period sea level variability is less affected by air pressure. Generally the sea level response to air pressure are found to be isostatic, but significantly nonisostatic for the periods around 4 months and for those of 2 to 4 days. In particular, nonisostatic response for higher frequencies seem to be due to the restrictions to water transport necessary for barometric responsein the Korea Strait.

• Korean journal of food and cookery science
• /
• v.14 no.1
• /
• pp.25-32
• /
• 1998

To measure the contents of several heavy metal elements (Cr, Mn, Ni, Cu, Zn, Cd, Hg, Pb) in Korean seaweeds which are closely related to food resources, various seaweed samples were collected from thirteen to seventeen seaweed-producing districts. The results obtained from the experiment are summarized as follows: 1. The content of heavy metal elements in seaweeds of individual sample ranged from 0.0005 to 25.0373 ppm. Their mean levels were as follows: laver, 0.0024∼3.9297 ppm; sea lettuce, 0.0011∼25.0373 ppm; sea mustard, 0.0005∼23.5071 ppm; sea tangle, 0.0006∼4.8550 ppm. The mean levels of Cd and Pb were specially low in the samples collected from the area II in Kangwon and area Ⅸ in Kyungbook. 2. The mean levels of heavy metal elements of collected samples ranged from 0.0117 to 4.4944 ppm. Laver showed the lowest level of Hg and sea lettuce showed the highest level of Mn. Their mean levels of elements were as follows: laver, 0.0117∼2.3339 ppm; sea lettuce,0.0232∼4.4944 ppm; sea mustard, 0.0129∼1.5139 ppm and sea tangle, 0.0182∼1.7410 ppm. 3. The mean levels of heavy metal elements from several locations ranged from 0.0085 ppm to 8.4148 ppm. The mean levels of heavy metal elements in sea mustard from area V of Kyungbook were the lowest, but the mean levels of heavy metal elements in sea lettuce from area Ⅷ of Kyungnam were the highest. The mean level of heavy metal elements were as follows: laver, 0.3613∼1.1124 ppm; sea lettuce, 0.1415∼8.4148 ppm; sea mustard, 0.0729-3.1182 ppm; sea tangle, 0.0085∼0.7587 ppm. 4. Generally the heavy metal elements were detected in the seaweed samples from all locations. The mean levels of heavy metal elements varied with locations and kinds of samples. The levels of heavy metals of the samples taken from all locations from the East Sea, the South Sea, and the West Sea areas showed 99% safety range.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.4 no.2
• /
• pp.93-100
• /
• 1999

Analyzing the tide data taken at Kunsan inner and Outer ports, non-tidal and mean sea level and harmonic constants of major constituents are investigated to examine the effects of the dyke gate operation on the sea level change in Keum River estuary. Non-tidal and annual mean sea levels decrease at Kunsan Inner and Outer ports after the dyke gate operation, especially showing an abrupt drop of non-tidal sea level at Kunsan Inner port. This non-tidal sea level drop results in the mean sea level gradient change between the inner and outer port, which can be mainly explained in terms of the decrease of river discharge from the dyke. Amplitudes of the $M_2$ and $S_2$ tides at the Inner port increase after the dyke gate operation, showing an abrupt jump, and phases of both tides slightly decrease. Amplitude and phase of the $K_1$ and $O_1$ tides show slight changes after the dyke gate operation. This significant change of semi diurnal tide amplitude is believed as a result of superposition of incident tidal wave and reflected tidal wave from the dyke.