• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.180-185
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• 2001

In order to regulate the physical characteristics of an ocean dumping material in the south-eastern East Sea, the diffusion characteristics with the observation, hydraulic experiment and numerical experiment data are investigated. The main results are as follows; (1) Spying CTD observation result of the area of Jung in the East Sea, the ocean dumping area had influenced the Tsushima warm current of high temperature and salinity. Horizontal turbulent diffusivity is 1.913${\times}$10$^{7}$ $\textrm{cm}^2$/sec by drogue tracking. (2) From the experiment of settling, the initial settling velocity of each material is 1.0∼2.7 cm/sec according to the specific gravity and initial concentration. In the pycnocline, particles didn't settle under the pycnocline any more and accumulated. It is signified that calculation of the sedimentation rate of the ocean dumping material including of vertical diffustion must be regard the pycnocline in the ocean area have well-developed pycnocline. (3) Vertical turbulent diffusivity were 2.219${\times}$10$^{-8}$∼8,874${\times}$10$^{-4}$ $\textrm{cm}^2$/sec from the experiment of settling. And, the pycnocline influenced the vertical turbulent diffusivity. (4) From the result of diffusion simulation in the East Sea, the co-concentration line of 0.05 ppm and 0.1 ppm are limited at dumping area after 200 days. The constant concentration line of 0.01 ppm is distributed to the vicinity of Ulleungdo and Tokdo, but isn't distributed to the coastal area of East Sea and southern area of Jung in the East Sea.

• Ocean Science Journal
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• v.40 no.1
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• pp.25-44
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• 2005

Long-term, continuous, and real-time ocean monitoring has been undertaken in order to evaluate various oceanographic phenomena and processes in the East/Japan Sea. Recent technical advances combined with our concerted efforts have allowed us to establish a real-time monitoring system and to accumulate considerable knowledge on what has been taking place in water properties, current systems, and circulation in the East Sea. We have obtained information on volume transport across the Korea Strait through cable voltage measurements and continuous temperature and salinity profile data from ARGO floats placed throughout entire East Sea since 1997. These ARGO float data have been utilized to estimate deep current, inertial kinetic energy, and changes in water mass, especially in the northern East Sea. We have also developed the East Sea Real-time Ocean Buoy (ESROB) in coastal regions and made continual improvements till it has evolved into the most up-to-date and effective monitoring system as a result of remarkable technical progress in data communication systems. Atmospheric and oceanic measurements by ESROB have contributed to the recognition of coastal wind variability, current fluctuations, and internal waves near and off the eastern coast of Korea. Long-tenn current meter moorings have been in operation since 1996 between Ulleungdo and Dokdo to monitor the interbasin deep water exchanges between the Japanese and Ulleung Basins. In addition, remotely sensed satellite data could facilitate the investigation of atmospheric and oceanic surface conditions such as sea surface temperature (SST), sea surface height, near-surface winds, oceanic color, surface roughness, and so on. These satellite data revealed surface frontal structures with a fairly good spatial resolution, seasonal cycle of SST, atmospheric wind forcing, geostrophic current anomalies, and biogeochemical processes associated with physical forcing and processes. Since the East Sea has been recognized as a natural laboratory for global oceanic changes and a clue to abrupt climate change, we aim at constructing a 4-D continuous real-time monitoring system, over a decade at least, using the most advanced techniques to understand a variety of oceanic processes in the East Sea.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.5-13
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• 1997

The Island of Cheju plans massive ground water development to meet predicted water demand. Effective management of ground water resources requires impact assessment study. Due to the nature of the island, effects of sea water must be considered. In this work, salt water intrusion, due to hypothetical ground water development in Eastern and Central Cheju Watersheds, is predicted using a sharp-interface model. The model considers simultaneously hydrodynamics of both freshwater and saltwater. The hypothetical ground water development was designed such that it follows closely the regional ground water development plan. The numerical model predicted that the saltwater wedge may intude over 1km depending on the location. This observation leaves doubt on impact assement studies based on freshwater-flow only modeling.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.41-49
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• 2008

Internal waves and internal tides occur frequently along the eastern coast of Korea. During the spring-tide period in April 2003, the East Korean Warm Current (EKWC) flowed near the Korean East Coast Farming Forecast System (KECFFS; a moored oceanographic measurement system), creating a strong thermocline at the intermediate layer. Weakened stratification and well-mixed water appeared frequently around the KECFFS, with duration of approximately 1 day. The results suggest the following scenario. Baroclinic motion related to the internal tide generated high frequency internal waves around the thermocline. The breaking of those waves then created turbulence around the thermocline. After well-mixed water appeared, a current component with perpendicular direction to the EKWC appeared within the inertial period. The change in stratification around the KECFFS locally broke the geostrophic balance as a transient state. This local vertical mixing formed an ageostrophic current within the inertial period.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.403-411
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• 1995

The atmospheric responses to a Sea Surface Temperature Anomaly(SSTA) over the equatorial eastern Pacific Ocean have been investigated using the horizontally fine resolution model based on OSU 2-layer Atmospheric General Circulation Model(AGCM). The SSTAS daring the peak phase of 1982-83 El Nino have been applied to the model as the boundary conditions of the experiment. The model simulates the eastward movement of the rising branch of the Walker circulation. That is, the major features associated with the El Nino such as the increase of the precipitation rate over the center of the Pacific and decrease over the Indonesia, and the 500hPa geopotential height anomaly in the middle latitude are properly describes in the fine resolution model experiment. The model results indicate that this horizontally fine resolution UM can successfully simulate the ENSO anomalies and be more effectivelly used for the study of the climate and the climate changes.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.1
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• pp.19-30
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• 2017

The altitudinal potential source contribution function (PSCFa) method was developed by considering topography and height of back trajectories. The PSCFa calculated on the contributions of trans-boundary transport to the hourly mean concentrations of aerosol optical depth (AOD) of the Aerosol Robotic Network (AERONET) in the Distributed Regional Aerosol Gridded Observation Networks (DRAGON) KORea-US Air Quality (KORUS-AQ) campaign from March 31 to July 1 in 2016. Eastern China ($33^{\circ}N{\sim}35^{\circ}N$ and $119^{\circ}E{\sim}121^{\circ}E$) can be the major source of trans-boundary pollution to the western area in South Korea resulted from PSCFa (0~700 m). In this study, AOD by Moderate Resolution Imaging Spectroradiometer (MODIS) was compared to verify the source regions. Regionally, the effects of the long-range transport of pollutants from the eastern China on air quality in south Korea have become more significant over this period.

• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.313-317
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• 2008

An investigation of the intertidal fish fauna was carried out based on the specimens collected at Sinweolseong on the eastern coast of Korea from February 2006 to October 2007. The collected fishes comprised 27 species belonging to 22 genera, 15 families and 5 orders. Family Cottidae was the most abundant in species and individuals, with Furcina osimae the most representative species in the sampling area. Hexagrammos agrammus appeared throughout the year, while Chaenogobius annularis and C. gulosus predominated. In addition, Zoarchias glaber and Goniistius zonatus, which were distributed on Jeju Island and the South Sea of Korea, were first recorded from this area.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.297-301
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• 2006

There are more than thirty continuously recording GPS stations (CORS) have been set up at different geological sites and distributed throughout a 140 km by 140 km area in southern Taiwan beginning since 2000, and the amount of the CORS are still under increasing in this area which is recognized the suture zone between the Philippe sea plate and Eurasia plate. From the year 2000 to the end of 2005, we analyze the daily solutions to obtain the average station velocities before and after the Chengkung earthquake which occurred near eastern Taiwan at 04:38 UTC on 10 December 2003. After considering the effects of the coseismic and postseismic displacements, the difference of the horizontal components reaches 13 mm/year of the average station velocity happened in the east side of the Central Range. To the vertical component, all of the stations are risen which located in the Coastal Range, and the largest difference approaches 20mm/year.

• Journal of The Geomorphological Association of Korea
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• v.25 no.3
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• pp.57-70
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• 2018

This study restores onshore paleo-shoreline records and establishes the nature and strain rate of neotectonism by investigating the existence and formative age of paleo-coastal sediments emerged around Sacheon-si in the Southern part of the Korean peninsula. As a result, paleo-sand bars representing 5m of the paleo-shoreline from high tide level are formed in Sacheon-si, and the formation age of these is confirmed as MIS 5c at approximately 100,000 year BP through rock surface luminescence dating to rounded gravels in paleo-sand bars. Although it is difficult to establish the uplift rate of crust precisely due to incomplete restoration of sea level records during the last interglacial stage, the uplift rate along the Southern coast of the peninsula was assumed approximately 0.72 lower than the Eastern coast during the late Quaternary in comparison to the 1st marine terrace along the Eastern coast.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.505-515
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• 2020

The Yellow Sea and northern East China Sea contain a transgressive sand layer. Numerous sedimentary studies have been carried out in these sand deposits using seismic exploration and core sediment techniques, but few mineralogical studies have been reported. The major purposes of this study are to describe the distributions of heavy minerals throughout the Yellow sea and northern East China Sea and to identify the provenance of coarse sediments using the mineral chemistry. Eight heavy mineral species were identified in the study area (epidote, amphibole, garnet, zircon, sphene, rutile, apatite, and monazite). The study region was divided into six areas (areas A to F) based on heavy mineral distributions and sampling locations. In mineral chemistry, the amphiboles present are classified as edenite and hornblende in the calcic amphibole group, and the garnets are identified primarily as almandine in the pyralspite group. A combined data set of heavy mineral distributions and mineral chemistry showed clear differentiation of the characteristics of the six classified areas, enabling determination of provenance and sedimentary environment. Area A and B in the eastern Yellow Sea were originated from the Korean peninsula, and these regions showed different heavy mineral characteristics by tidal current and coastal current. In addition, monazite was only found in the area B and could be used as an indicator from the southwestern Korean peninsula. Area D and E in the western Yellow Sea showed the characteristics of sediments originating from the Huanghe, and sediment in the area E was derived from the Changjiang. Area C in the northern East China Sea appeared to have Changjiang-origin sediment, and abundant apatite indicated that area C was formed close to the Last Glacial Maximum.