• Title/Summary/Keyword: Eastern Yellow Sea

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The Natural Environment during the Last Glacial Maximum Age around Korea and Adjacent Area

  • Yoon, Soon-Ock;Hwang, Sang-Ill
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.33-38
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    • 2003
  • This study is conducted to examine the data of climate or environmental change in the northeastern Asia during the last glacial maximum. A remarkable feature of the 18,000 BP biome reconstructions for China is the mid-latitude extention of steppe and desert biomes to the modem eastern coast. Terrestrial deposits of glacial maximum age from the northern part of Yellow Sea suggest that this region of the continental shelf was occupied by desert and steppe vegetation. And the shift from temperate forest to steppe and desert implies conditions very much drier than present in eastern Asia. Dry conditions might be explained by a strong winter monsoon and/or a weak summer monsoon. A very strong depression of winter temperatures at LGM. has in the center of continent has influenced in northeast Asia similarly. The vegetation of Hokkaido at LGM was subarctic thin forest distributed on the northern area of middle Honshu and cool and temperate mixed forest at southern area of middle Honshu in Japan. The vegetation landscape of mountain- and East coast region of Korea was composed of herbaceous plants with sparse arctic or subarctic trees. The climate of yellow sea surface and west region of Korea was much drier and temperate steppe landscape was extended broadly. It is supposed that a temperate desert appeared on the west coast area of Pyeongan-Do and Cheolla-Do of Korea. The reconstruction of year-round conditions much colder than today right across China, Korea and Japan is consistent with biome reconstruction at the LGM.

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Structure of Shelf Front and Distribution of Plankotns in the Eastern Part of the Yellow Sea (황해동부의 대륙붕전선의 구조와 부유생물의 분포)

  • CHO Kyu Dae;HONG Seong Yoon;KIM Hee Joon;YANG Yong-Rhim
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.316-329
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    • 1983
  • The formation and structure of the shelf front in the eastern part of the Yellow Sea are studied on the basis of oceanographic data collected in August, 1982 and February, 1983. This paper also describes the distribution of planktonic organisms of the shelf front. In summer the shelf front is formed in the area ($126^{\circ}02^'E-126^{\circ}05^'E$) ca. 20 miles from the shore at the depths of 15-25 m. in winter, however, no distinct shelf front is formed. Based on the cluster analysis of surface phytoplankton the species composition shaws a discontinuous pattern in the vicinity of the shelf front in summer, 1982. A similar trend is observed in distribution of some copepod species in winter, l983.

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Seasonal characteristics of zooplankton community in the Mid-eastern part of the Yellow Sea (황해 중동부 해역 동물플랑크톤의 계절적 분포 특성)

  • 황학진;최중기
    • 한국해양학회지
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    • v.28 no.1
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    • pp.24-34
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    • 1993
  • In order to study the seasonal characteristics of species composition and abundance, zooplankton samples were collected from April 1987 to June 1988 with bimonthly intervals in the Mid-Eastern part of the Yellow sea. Among the 24 species of 18 genera occurred in this study area, 17 species are copepods. Noctiluca scintillant has greatly influenced on the distribution of the zooplankton in the coastal area and some copepods may be excluded by its great occurrence. the seasonal variation of abundance of copepods accounting for 30-63.4% of total zooplankton were more varied among stations in the coastal area than in the offshore. It suggests that environmental factors are more variable in the coastal area than in the offshore. In the Copepod community, Acartia omorii, Paracalanus parvus and Corycaeus affinis were predominant in April and June, from August to December and in December, respectively. Sagita enflata as a Kuroshio indicator species, occurred in the study area from August to December. The great occurrence of warm water species, Doliolum sp. in October and the occurrence of Sagitta enflata from August to December suggested that there is a influx of the tributaries of Kuroshio current into the study area. It appeared that the seasonal characteristics of species composition and abundance of zooplankton were affected by the seasonal variation of water mass.

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Variation of sulfur dioxide concentrations at Kangnung under the Influence of Regional Meteorology for the Period of Yellow Sandy Dusts in Spring (봄철 황사기간중 지역기상 영향에 의한 강릉지역에서의 아황산가스 농도 변화)

  • Choi, Hyo
    • Journal of Environmental Science International
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    • v.5 no.2
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    • pp.131-140
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    • 1996
  • Analysis of hourly variations of sulfur dioxide ($SO_2$) concentrations affected by regional climates for the period of yellow sandy dusts was carried out from March 31 through April 9, 1993. The concentration of 50, at a coastal city, Kangnung city, was much higher than that at an inland city Wonju in the west, but the hourly distrbutions of $SO_2$ concentrations show a similar tendency at both cities. Under the prevailing synoptic-scale westerly winds blowing over a high Mt. Taegualyang in the west toward Kangnung city in the eastern coastal region, the $SO_2$ at Kangnung is trapped by an easterly sea-breeze during the day and under prevailing easterly winds, it is also isolated by the high wall of Mt. Taegualyang, with its high concentration from 14 to 16 LST. Furthermore, when the westerly winds were dominent all day long the high $SO_2$ concentrations at Kangnung were produced by its intrusion from a urban city, Wonju or China in the west into a mountainous coastal city, Kangnung, to some extent, and when the air becomes rapidly cooled down at the clear daytime or the nighttime, their concentrations are also increased by a great amount of heating fuel combustion. Especilly, its maximum concentrations were shown in Wonju and Kangnung from 08 LST through 10 LST, due to the increase of auto vehicles near the beginning time of office hour and were detected again after sunset due to both increases of vehicles at the end of office hour and heating fuel combustion. During the period of Yellow Sandy Dusts which are transported from China into Korea, the $SO_2$ concentrations on rainy days at Wonju and Kangnung were much lower than the monthly mean values of $SO_2$, and their low concentrations could be caused by the scavenging process of rain.

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The Distribution Characteristics of Floating Debris on the Cruising Routes from Cheju Island to Qindao Harbor in the Yellow Sea (한국 제주도와 중국 청도의 항로상에 부유하는 해양폐기물의 분포에 관한 연구)

  • Kim, Min-Suk;Kim, Jong-Hwa;Kim, Sam-Kon
    • Journal of Fisheries and Marine Sciences Education
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    • v.11 no.2
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    • pp.203-215
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    • 1999
  • Floating debris was recorded from a training ship, Kaya, of Pukyong National University with about 12 knots speed at July 19~21, 1999 and July 24~26. The sampled area is the Yellow Sea (YS) connected from Cheju Is. of Korea to Qindao harbor of China, divided into 88 unit segments on survey routes. Debris fabrication materials were categorized with 6 items using the following; man-made or natural wood items, paper and cardboard, nylon netting and rope, styrofoams, vinyl and plastics, floating metal and glass containers. All identified items within a $120{\pm}20m$ wide band were recorded but ignored if beyond this boundary. The results of distribution of floating debris in the area are as follows: 1. The greatest quantities of marine debris discovered during the survey were $184pieces\;per\;km^2$ near Qindao harbor. The next polluted areas, Sohuksan islands, positioned in the eastern part of YS were scattered in about $40pieces/km^2$ or so. 2. Among items, woods, paper and cardboard, vinyl and plastics were found out near Qindao Coast of China. On the other hand, there were many styrofoams, nylon netting and rope near the area of Sohuksan islands in the eastern part of YS. 3. The distribution densities of western part of YS near Qindao are varied with largely range in items and quantities but those of the eastern part, near Sohuksan islands were nearly constant. 4. Styrofoams were composed of 63% among all debris in YS, next paper and cardboard 15%, and wood item, vinyl and plastics each 10%. Therefore, marine debris of YS is revealed that distribution characteristics and composition are very different in each area. These phenomena are concluded that they largely depend on the life styles in land and the utilities of the sea. And of items, styrofoams is dominated by the distribution pattern of YS. Furthermore, surveys are continuously being investigated, and from this it is hoped that a much wider coverage can be achieved, perhaps all sites of the YS and contributed to the finding sources, the stationary area and removal method of debris joined the flow patterns.

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Correlation of Simrad EM950(95kHz) Multibeam Backscatter Strength with Surficial Sediment Properties in the Sand Ridge of the Eastern Yellow Sea (황해 동부 사퇴분포지역의 표층퇴적물 특성과 Simrad EM950(95 kHz)멀티빔 후방산란 음압간 상관관계)

  • Kong, Gee-Soo;Kim, Seong-Pil;Park, Yo-Seop;Min, Gun-Hong;Kim, Ji-Uk;Park, Soo-Chul
    • Economic and Environmental Geology
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    • v.39 no.6 s.181
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    • pp.719-738
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    • 2006
  • Simrad EM950 multibeam data and surficial sediment grab samples were acquired to correlate backscatter strength with surficial sediment properties in the eastern Yellow Sea which tidal sand ridges are dominantly developed. The study area is divided into the western sand ridge zone characterized by well sorted, fine sandy sediment, and the eastern non-sand ridge zone characterized by poorly sorted, medium sand with some gravels and shell fragments. In spite of minor difference in grain size between two zones, the variations of backscatter strength between two zones are distinct. Multibeam backscatter strength of study area shows good correlation with the grain size of surface sediment as well as the carbonate contents. High occurrence of carbonate shell fragments can increase grain size and bottom roughness. The dominance of higher backscatter strength in the eastern non-sand ridge zone may reflect the effects of coarse grain size and high shell fragments contents.

A Three-Dimensional Numerical Study of Effects of Typhoons on Oceanographic Conditions in the Korea Strait

  • Hong, Chul-Hoon
    • Journal of the korean society of oceanography
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    • v.34 no.2
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    • pp.73-85
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    • 1999
  • When typhoons passed around the Korea Strait, some observation in this strait carried out by Mizuno et al. (1986) gives us the following oceanographic features; 1) the direction of the observed current was opposite to the northeasterly wind, 2) temperature rapidly increased having a time lag as the depth deepens, after then decreased with oscillation. A primitive equation ocean model that makes use of a sigma-coordinate system and incorporates a typhoon model was used to examine the mechanism to generate these phenomena. The model region covers the East China Sea, the Yellow Sea, and a portion of the East Sea (Japan Sea). The model well reproduces the observed features, especially in temperature field, and clearly manifests how the above observed features happened. From early time when the typhoon was located in low latitude, an alongshore northward current in the west of Kyushu (hereafter the West Kyushu Current) is generated by an alongshore wind in the typhoon. This current flows into the eastern channel, as a coastal jet, regardless to the wind field within the Korea Strait during this period. The above observed phenomena are generated by this current. The model results indicate that when typhoons pass around the Korea Strait, the West Kyushu Current is generated, and oceanographic condition in the strait should be greatly influenced by this current.

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A fine grid two-dimensional $M_2$ tidal model of the East China Sea (동지나해의 세격자 2차원 $M_2$조석모형)

  • 최병호
    • Water for future
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    • v.21 no.2
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    • pp.183-192
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    • 1988
  • The previous two-dimensional non-linear tidal model of the East China Sea(Choi, 1980) has been further refined to resolve the flow over the ocntinental shelf in more detail. The mesh resolution of the present finite-difference grid system used is 4 minutes latitude by 5 minutes longitude over the entire shelf. The developed fine grid two-dimensional model was utilized to reproduce the $M_2$ tide and $M_4$ tide for the East China Sea contnental shelf. There is general agreement between the model results and the current observation made in the Eastern Yellow Sea, which supports the calculated tidal regime over the shelf. Some preliminary results on maximum bottom stress and tidally-induced residual current were also examined and discussed.

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Population Genetic Structure of Japanese Anchovy (Engraulis japonicus) in Korean waters Based on Mitochondrial 12S Ribosomal RNA Gene Sequences (미토콘드리아 12S 리보종 RNA 유전자배열에 의한 한국해역 멸치 개체군의 유전자 구조)

  • Kim Jin Yeong;Cho Eun Seob;Kim Woo Jin
    • Journal of Life Science
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    • v.14 no.6 s.67
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    • pp.938-950
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    • 2004
  • We used portions of mitochondrial 125 ribosomal RNA gene sequences (339 bp) to investigate the phylogenetic and population genetic characteristics of the Japanese anchovy, Engraulis japonicus, in Korean waters. A total of 35 mtDNA haplotypes were obtained from the samples collected in 3 locations (the southern area of the Yellow Sea, the western coast of Jejudo, and the eastern area of the South Sea) in Korean waters. One haplotype, AN8T103, obtained from the southern area of the Yellow Sea, was formed according to an independent phylogenetic individual in the PAUP analysis, which was separated from the others by a $0.2-4.1\%$ sequence divergence. This distinct haplotype appeared to be one that was carried by immigrants from another study area, but further study is necessary. Genetic divergence, except for AN8T103, was moderate to substantial $(0.2-3.8\%)$ and nucleotide diversity within populations was 0.015 for Yellow Sea, 0.013 for Jejudo, and 0.D15 for South Sea, respectively. The female gene flow was substantial or high (Nm=25.5-36.4), and the genetic distances between regions were not statistically significant $(P>0.01)$. These results indicated that the Japanese anchovy populations occurring in Korean waters were consisted of individuals randomly dispersed over geographic areas.

The Maritime Geography of Korea Strait: Suggested Nomenclature and Cartographic Boundaries Derived from a Review of Historical and Contemporary Maps (국제학술지, 지도, 문서에 나타난 대한해협 해양지명과 경계에 대한 인식 변화)

  • DO-SEONG BYUN;BYOUNG-JU CHOI
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.28 no.2
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    • pp.63-93
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    • 2023
  • This study aims to examine the history of naming the strait between the Yellow and East China Seas and the East Sea to suggest a consistent nomenclature and to demarcate the geographic region of the strait. Although the strait is internationally known as 'Korea Strait', it is commonly referred to as the 'South Sea' in Korean common usage. This review ultimately recommends the use of 'Korea Strait' as an appropriate geographical name for this area. To support this recommendation, the historical boundaries typically assigned to the Korea Strait were investigated. We also analyzed the evolution of geographical labels assigned to Korea Strait and to the Western and Eastern Channels (labels given to the two maritime areas surrounding Tsushima). Resources for this analysis included historic maps and charts, International Hydrographic Organization Special Publications (S-23), and maps published in the Ocean Science Journal (OSJ) and Journal of Oceanography (JO), which are two international journals representing Korean and Japanese sources, respectively, from 2005 to 2021. In these two international journals, the most frequently used names assigned to the strait of interest were Korea Strait (appearing 42.9% of OSJ maps, and 7.5% of JO maps), and Tsushima Strait (appearing 60.4% of JO maps, and 0% of OSJ maps). Other names were South Sea and Korea Strait/Tsushima Strait. On maps in the two reviewed journals, the boundaries of Korea Strait were defined explicitly or implicitly in five different ways: a broad region between the Yellow and East China Seas and Ulleung Basin (Type 1), the region between Ulleung Basin and Tsushima (Type 2), the western channel of the strait (Type 3-1), the eastern channel of the strait (Type 3-2), and both the western and eastern channels of the strait (Type 4). Overall, Type 1 was the most frequently used boundary, taking up 71.4% of OSJ and 60.4% of JO maps. Lastly, we suggest in this paper that the current flowing through Korea Strait from the East China Sea to the East Sea should be labeled the 'Korea Strait Warm Current' to indicate its full path through the strait. Currently, this current is internationally referred to as the 'Tsushima Warm Current', which does not link well to the commonly used geographic name of the strait.