• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.1
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• pp.31-36
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• 2006

A study on estimation of the datum level is carried out by combining observed and simulated harmonic constants of 4 major tides ($M_2$tide, $S_2$tide, $K_2$tide, and $O_1$tide). In the coastal zone, the datum level can be estimated by using observed tide harmonic constants at tide station. The observed tide harmonic constants, however, cannot be used to calculate the datum level of the sea because of the lack of tide station. In order to estimate the datum level of the sea, it is necessary to adopt the simulated harmonic constants instead of the observed ones. In this study, the datum level is calculated by using the simulated harmonic constants which is modified by tuning coefficient based on relationship between observed and simulated harmonic constants at tide station. Tuning coefficient of sea is interpolated on TIN (Triangulated Irregular Network) which has node points at tide stations.

• Korean Journal of Microbiology
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• v.10 no.3
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• pp.97-104
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• 1972

The extent of water pollution was investigated at 4 stations in Kyonggi Bay during the summer seasons in 1970 and 1971. The concentrations of dissolved oxygen, total hardness, ammonia, nitrate, nitrite, phosphate, chemical oxygen demand, salinity, biochemical oxygen demand, coliform bacteria and facel coli were examined together with the measurement of pH and transparency. The relationship between the extent of pollution and the distance from the Inchon Bay also was examined. The concentrations of biochemical oxygen demand, chemical oxygen demand, ammonia, nitrate, nitrite, phosphate, coliform bacteria nad fecal coli were all highest at station 1, and lowest at station 4. Values were somewhat higher at low tide level in general. On the contrary, dissolved oxygen concentration was highest at station 4 and lowest at station 1. The highest and lowest values of biochemical oxygen demand were 10.88 ppm at station 1 and 0.27 ppm at station 4. The chemical oxygen demand concentrations at station 1 and 4 were 1.90 ppm and 0.63 ppm. Ammonia concnetration at station 1 was 0.43 pp, and was nearly 5 times as much as that at station 4. The values were $2.45{\times}10^{-4}$ ppm at station 1, and $6{\times}10^{-4}$ ppm at station 4. Nitrite concnetration at station 1 was $3{\times}10^{-4}$ppm and was the highest, while the lowest was $9.45{\times}10^{-5}$ ppm at station 4. Phosphate value at station 1 too was the highest and was about 4 times as much as that at station 4. Coliform bacteria were most abundant at station 1, and were counted to be 1.$1.7{\times}10^{-5}$cells/ml. At station 4, the number greatly reduced to 8 * 10$^{2}$ cells/ml. The number of fecal coli at station 1 was $2{\times}10^{-4}$ cells/ml. But at station 4, no fecal coli was detected at high tide level. At low tide level, 3 cells/ml were counted at station 4. In all of these, the highest data were obtained at low tide level, while most of the lowest value, at high tide level. Generally, values at statio 1 were 3-5 times as much as those at station 4. Concentration of dissolved oxygen at station 1 was 0.366 mg-atoms/1 and was the lowest. The highest value was 0.420 mg-atoms/1 and was recorded at station 4. The highest at station 4, which certainly were believed to be the result of the dilution by the fresh water of the Han river flowing into the Inchon Bay. As we can see from the data above, the extent of pollution was highest at station 1, the nearest from Inchon harbor, and lowest at station 4, where is the farthest, Station 1 and 2 were proved to be much polluted, but station 3 and 4, not.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.70-75
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• 1998

The comparison of Topex/Poseidon sea surface heights and Tide Gauge sea levels was studied in the South Indian Ocean after Topex/Poseidon mission of about 3 years (11- 121 cycles) from January 1993 through December 1995. The user's handbook (AVISO) for sea surface height data process was used in this study Topex/Poseidon sea suface heights ($\zeta$$^{T/P}$), satellite data at the point which is very closed to Tide Gauge station, were chosen in the same latitude of Tide Gauge station. These data were re-sampled by a linear interpolation with the interval of about 10 days, and were filtered by the gaussian filter with a 60 day-window. Tide Gauge sea levels ($\zeta$$^{Argos}$, $\zeta$$^{In-situ}$ and $\zeta$$^{Model}$), were also treated with the same method as satellite data. The main conclusions obtained from the root-mean-square and correlation coefficient were as follows: 1) to Produce Tide Gauge sea levels from bottom pressure, in-situ data of METEO-FRANCE showed very good values against to the model data of ECMWF and 2) to compare Topex/Poseidon sea surface heights of Tide Gauge sea levels, the results of the open sea areas were better than those of the coast and island areas.

• Journal of Environmental Science International
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• v.23 no.5
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• pp.801-806
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• 2014

Long-term change in sea level along the eastern coast of Korea was illustrated using four tide-gauge station (Pohang, Mukho, Sokcho, Ulleung) data, water temperature and salinity. Seasonal variation in the sea level change was dominant. The sea level change by steric height derived from water temperature and salinity was relatively lower than that measured from the tide-gauge stations. Sea level rising rate per year by steric height increased with latitude. The effect of salinity(water temperature) on the sea level change is greater in winter(in summer).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.452-458
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• 1994

The advantage of tide-well system with an intake pipe near the sea floor is that it can record not only tide but also harbour oscillation. tsunami. rapid change of tide height when a storm was causing rapid fluctuations in sea level. Consequently record of harbour oscillation may be extracted from tidal records by removing the predicted tide and then correcting for the attenuation caused by the tide-well system. The response of tide-well with intake pipe to seiche was examined by in situ measurements for Mukho tidal station. The well constant was also computed hydraulically on the basis of the structure of the tide gage system. It has been found that the response coefficient of the Mukho tidal station was 0.01. The tide records can be used for the determination of mean sea levels for surveying purposes. as the response of tide-well system can be estimated.

• Korean Journal of Remote Sensing
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• v.3 no.2
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• pp.81-87
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• 1987

The study was to analysis the dispersion of the cooling water of Kori atomic power station using thermal infrared data. The dispersion pattern of the cooling water analysis clearly on the LANDSAT TM band 6. It was changed due to tidal current, that is, the cooling water disperses north-eastern direction during the low tide and southweatern direction during the high tide. The relative temperature distribution was mapped through the density slicing method on the images.

• Ocean and Polar Research
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• v.24 no.3
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• pp.249-253
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• 2002

There is a great deal evidence concerning crustal uplift, after deglaciation, in the vicinity of Syowa Station $(69^{\circ}S,\;39^{\circ}E)$ from tide gauge data, seismic evidence, raised beaches, marine terraces, etc. The geomorphological and tide gauge data show that the crustal uplift is going on around Syowa Station. Seismic observations at Syowa Station started in 1959. Phase readings of the earthquakes have been published by National Institute of Polar Research once a year since 1968, as one of the Data Report Series. Eighteen local earthquakes were detected on short period seismograms at Syowa Station in 1990-2000. The seismicity during the period from 1990 to 2000 was lower than that from 1987 to 1989 when epicenters of local earthquakes were determined by tripartite seismic array. Local earthquake activity corroborates the crustal uplif4 which is an intermittent phenomenon. Sea level falling of 4.5 mm/y was found using data in 1975-1992. This felling rate is consistent with the geomorphological data. A route for repeat leveling survey was established in East Ongul Island. No appreciable change of sea level was observed for the last 14 years. A dynamics of the crustal uplift around Syowa Station has been discussed using geomorphological data, ocean tide, and seismic and leveling data, which is estimated to be an intermittent phenomenon. When local seismic activity is high, the crustal uplift is estimated to be going on. On the contrary, the crustal uplift is in dormancy when the local seismicity is low. Repeated leveling measurements suggest no significant changes, which further supports the idea that the crustal uplift in offshore is not a tilt trend movement but a block movement.

• Proceedings of the KSRS Conference
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• v.2
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• pp.756-759
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• 2006

The ocean tide loading (OTL) is an important factor for the GPS positioning, especially in the height direction. The shorter of the distance to the ocean, the larger of the error by the OTL. The influence will be changed when we measure in different place and the order of magnitude is from few centimeters to ten centimeters. In this study, more than ten kinds of the OTL models were collected and applied on the GPS static relative positioning in Taiwan. The GPS observations including five stations were obtained from Nov. 9, 2004 to Feb. 23, 2005 and we used the Bernese GPS software to execute the data processing. In this period, the average amplitudes of the 3-D coordinates are as follows: N is 0.4 cm, E is 0.7 cm, h is 1.8 cm at Kinmen station; N is 0.7 cm, E is 1.3 cm, h is 2.3 cm at Lanyu station; N is 0.5 cm, E is 0.7 cm, h is 2.0 cm at Matsu station; N is 0.6 cm, E is 0.6 cm, h is 2.0 cm at Penghu station and N is 0.5 cm, E is 1.2 cm, h is 1.7 cm at Hsinchu station. Moreover, we will analyze the advantage and disadvantage of every kind of the OTL models in different environments to offer some information to the GPS users and enhance the precision of the GPS positioning.

• International Journal of Contents
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• v.18 no.1
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• pp.76-84
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• 2022

Tidal power generation plays a critical role in reducing greenhouse gas emissions. It uses a tidal force generated by gravitational force between the moon, the earth, and the sun. The change of seawater height generates the tide-generating force, and the magnitude of the change is the tide level. The tide level change has the same period as the tide-generating force twice a day, every 29.5 days, every year, and every 18.6 years. Sihwa Lake Tidal Power Station is Korea's first tidal power plant that began commercial power generation in August 2011 and has been accumulating a large volume of data on electricity production, power generation sales, sluice displacement, and tide levels. The purpose of this paper was to analyze the impact of the inefficiency factors affecting production and the tidal level change on tidal power generation and their characteristics using Sihwa Lake Tidal Power's operational performance data. Throughout this paper we show that tidal power generating operation is accurately predicting the trends of magnitude of tidal force to be periodical for each day. determining the drop to initiate the water turbine generator factoring the constraints on the operation of Sihwa Lake, and reflecting the water discharge through the floodgate and water turbine during the standby mode in the power generation plan to be in the optimal condition until the initiation of the next power generation can maximize power generation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.270-276
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• 2014

Seasonal characteristics of water and sediment qualities and potential effects of the freshwater discharge from a small tide embankment interior in a coastal area in Goheung county were investigated from May to September in 2012. Chemical oxygen demand values (COD) were mostly higher than 2 mg/L in summer ebb tide, which exceed the standard value of water quality criteria II of acceptable level for aquaculture activities. Nitrogen and phosphorus were found as the limiting nutrients for algae growth in summer and fall and in spring, respectively. Nitrogen was the limiting nutrient for diatom growth in the whole studied period. The sudden high values of COD, ammonia, dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) were found in water sample collected from station 5 which located in front of the tide embankment sluice gate during spring ebb tide. The freshwater discharge form the tide embankment interior maybe affected the survey areas during a short time interval. Mean values of eutrophication index of the surveyed coastal region in spring, summer and fall were all bigger than 1. Water quality was mostly considered at level II which acceptable for aquaculture activities. Sediment quality in this study was generally in the range of standard for fisheries environment.