• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.89-100
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• 2012

The aim of this study knows to occurrence characteristics and monthly transition of foreign marine debris by changing in the marine environment for the national marine debris monitoring areas in the west coastal area. The Jeju Island (5,112) had the highest number for foreign marine debris flowed in the coast. Many areas in the next were surveyed by Hajo Island (1,967), Imja Island (507). Plastic bottles were the most common type to 2,925 piece of the whole collection. Then, the monthly occurrence amount was concentrated in July, September. At this time, analysis results of the marine environment are as follows: The sea surface wind of southerly or southeasterly were predominated. In addition, the sea surface circulations were dominated by inflow of seawater southward along the China Coast and northward from the East China Sea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.4
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• pp.203-213
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• 1998

To investigate impacts of waste disposal on the marine environment for 9 years since dumping activity commenced in the Yellow Sea, chemical analysis of seawater has been done in and around the ocean dumping site. Results show that biogeochemical changes have occurred locally in the dumping area compared with the reference area, resulting in low dissolved oxygen saturation, low pH, and high accumulation of nutrients in the bottom layer. According to cluster analysis, chemical environment of the study area can be largely divided into surface layer and bottom layer, and again the bottom layer can be divided into that of dumping area where nutrients are accumulated and that of reference area. Low pH, low dissolved oxygen, high COD and accumulation of nutrients mainly characterize the dumping area. Average concentration of total inorganic nitrogen in the bottom layer below the thermocline has increased from $3.7{\mu}M$ to $9.5{\mu}M$, 250% accumulation in the dumping area since 1988. Therefore, the present results clearly show that the dumping site of Yellow Sea has received excessive sewage input beyond the environmental assimilatory capacity during the last decade. It may result in serious aggravation of seawater quality and basic ecosystem, and devastation of overall fishing grounds of Yellow Sea in the near future.

• 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.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.1
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• pp.57-74
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• 2009

In order to clarify the vertical ozone distribution in planetary boundary layer of coastal area with complex terrain, an observation campaign was carried out around Gwangyang Bay with dense pollutant emission sources during two days from June, 4 2007. For this observation are Radiosonde, SODAR(SOnic Detection And Ranging) and Tethered ozone sonde were employed. The surface meteorological and photochemical observation data provided by AWS (Automatic Weather System) and AQMS (Air Quality Monitoring System) were also applied for analysis. Synoptic condition is strongly associated with lower level ozone distribution in complex terrain coastal area. Since mesoscale circulation induced by difference of characteristics of land and sea and orographic forcing is predominant under calm synoptic condition, vertical distribution of ozone is complicate and vertical ozone concentration greatly fluctuated. However in second day when synoptic influence become strong, ozone concentration in lower levels is vertically uniform regardless of observation level. This results in vertical observation indicates that vertical ozone distribution is often determined by synoptic condition and also affects surface ozone concentration.

• Ocean and Polar Research
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• v.28 no.4
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• pp.395-405
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• 2006

We measured the fugacity of $CO_2$ $(fCO_2)$, temperature, salinity, nutrients and chlorophyll a in the surface water of the western North Pacific $(4^{\circ}30'{\sim}33^{\circ}10'N,\;144^{\circ}20'{\sim}127^{\circ}35'E)$ in September 2002. There were zonally several major currents which have characteristics of specific temperature and salinity (NECC, North Equatorial Counter Current; NEC, North Equatorial Current; Kuroshio etc.). Surface $fCO_2$ distribution was clearly distinguished into two groups, tropical and subtropical areas of which boundary was $20^{\circ}N$. In the tropical Int surface $fCO_2$ was mainly controlled by temperature, while in the subtropical area, surface $fCO_2$ was dependent on total inorganic carbon contents. Air-sea $CO_2$ flux showed a large spatial variation, with a range of $-0.69{\sim}0.79 mmole\;m^{-2}day^{-1}$. In the area of AE (Anticyclonic Eddy), SM(Southern Mixed region) and NM (Northern Mixed region), the ocean acted as a weak source of $CO_2$ $(0.6{\sim}0.79 mmole\; m^{-2}day^{-1})$. In NECC, NEC, Kuroshio and ECS (East China Sea), however, the fluxes were estimated to be $-0.3mmole\; m^{-2}day^{-1})$ for the first three regions and $-1.2mmole\; m^{-2}day^{-1})$ for ECS respectively, indicating that these areas acted as sinks of $CO_2$. The average air-sea flux in the entire study area was $0.15mmole\;m^{-2}day^{-1})$, implying that the western North Pacific was a weak source of $CO_2$ during the study period.

• Atmosphere
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• v.29 no.2
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• pp.149-164
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• 2019

The purpose of this study is to introduce the improvement of current operational climate prediction system of KMA and to compare previous and improved that. Whereas the previous system is based on GloSea5GA3, the improved one is built on GloSea5GC2. GloSea5GC2 is a fully coupled global climate model with an atmosphere, ocean, sea-ice and land components through the coupler OASIS. This is comprised of component configurations Global Atmosphere 6.0 (GA6.0), Global Land 6.0 (GL6.0), Global Ocean 5.0 (GO5.0) and Global Sea Ice 6.0 (GSI6.0). The compositions have improved sea-ice parameters over the previous model. The model resolution is N216L85 (~60 km in mid-latitudes) in the atmosphere and ORCA0.25L75 ($0.25^{\circ}$ on a tri-polar grid) in the ocean. In this research, the predictability of each system is evaluated using by RMSE, Correlation and MSSS, and the variables are 500 hPa geopotential height (h500), 850 hPa temperature (t850) and Sea surface temperature (SST). A predictive performance shows that GloSea5GC2 is better than GloSea5GA3. For example, the RMSE of h500 of 1-month forecast is decreased from 23.89 gpm to 22.21 gpm in East Asia. For Nino3.4 area of SST, the improvements to GloSeaGC2 result in a decrease in RMSE, which become apparent over time. It can be concluded that GloSea5GC2 has a great performance for seasonal prediction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.3
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• pp.155-162
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• 2008

The seawater in the Taean area was surveyed to evaluate the conditions of the bay and compliance with the bacteriological criteria for a designated area for shellfish production for export. Samples of seawater were collected monthly at 34 sampling stations established in the survey area from January 2002 to December 2004. The bacterial density in the coastal area close to a pollution source located to the northeast of the survey area was higher than in the open sea to the west. The bacteriological counts in the water did not change with 16.5mm of rainfall, but increased abruptly after 65.4mm of rainfall. The total coliform and fecal coliform most probable numbers (MPNs) of 1,224 seawater samples in the survey area were <1.8-2,400 and <1.8-790 MPN/100 mL, respectively. The geometric mean and estimated 90th percentile of total coliforms were 1.9-3.4 and 2.7-26.3 MPN/100mL, respectively, and for fecal coliforms were <1.8-2.6 and 1.8-12.0 MPN/100mL, respectively. The bacteriological water quality in the Taean seawater area met the National Shellfish Sanitation Program criteria for an approved area and the Korea Shellfish Sanitation Program criteria for a designated area for shellfish production for export.

• Journal of Environmental Science International
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• v.20 no.2
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• pp.275-289
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• 2011

In order to clarify the relation between sea breeze penetration and Planetary Boundary Layer development in southeastern part of the Korean Peninsula, several numerical assessments were carried out using atmospheric numerical model WRF(Weather Research and Forecasting). Compared with onset time of sea breeze at eastern coast area(Uljin), the time at southern coast region(Masan) with complex costal line tend to delay for several hours. The penetration patterns of sea breeze between two coastal regions are some different due to the shape of their coastal line and back ground topography. Intensified valley wind due to high topography of lee side of Uljin can help penetration of sea breeze at early time. So penetration of sea breeze at early time often prevent PBL to develop at Uljin and lower PBL height last for a day time. But because of late penetration of sea breeze at Masna, PBL Height dramatically decrease after 1500LST. The distribution of front genesis function based on the heat and momentum variation are explained obviously the sea breeze penetration patterns and agreed well with the PBL height distribution.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.296-305
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• 2018

Maturity and spawning of the pointhead flounder, Hippoglossoides pinetorum were investigated on the basis of samples collected in the coastal waters off Gangwon-do, East Sea from January 2012 to December 2013. The average total length of H. pinetorum was 25.0 cm and 21.9 cm for females and males, respectively. The spawning period was from May to July according to monthly changes gonadosomatic index (GSI) and maturity stages. The spawning period in Gangwon-do was delayed relatively to that in Gyeongbuk-do. The mature egg diameter ranged between $300-700{\mu}m$. The relationship between TL and fecundity (F) was F = 63.574 TL - 1471.3 ($R^2=0.7603$), that is, the larger total length, the more fecundity H. pinetorum had. We estimated that the TLs at 50% group maturity were 25.6 cm for females and 19.9 cm for males. The spawning ecology by sea area should be considered efficient resource management for H. pinetorum. Furthermore, it is necessary to study more on the relationships among growth, maturity and water temperature variations in the East Sea.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.117-121
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• 2001

For the effective development or preservation of Tokdo, the natural environments in the ambient sea area should be well investigated. The wave deformations and wave breaking in the vicinity have much affected the bottom morphology of Tokdo as well as its ecological environment. The present study investigates the wave deformations and wave breaking through a numerical model. The final goal is to provide the fundamental wave data for the effective development or preservation of Tokdo in future. The extended mild slope equation was applied to Tokdo sea area for three different deep water wave conditions (S, SSE, NNE directions). The results showed that for the S and SSE directions the wave heights in the area between the east island and the west island were very low with the level of 1~2m, but for the NNE direction they appeared pretty high with 3~4m, In the sea area near the northwest of west island, the wave heights were low to be 1~3m for all three directions of deep water wave.