• 제목/요약/키워드: oceanography

검색결과 2,884건 처리시간 0.044초

Application of Equilibrium Partitioning Approach for the Assessment of Polychlorinated Biphenyls (PCBs) Contamination in Sediments from Kyeonggi Bay, Namyang Bay, and Lake Shihwa, West Coast of Korea

  • Lee, Kyu-Tae;Tanabe, Shinsuke;Koh, Chul-Hwan
    • Journal of the korean society of oceanography
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    • 제34권1호
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    • pp.36-42
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    • 1999
  • To assess present status of polychlorinated biphenyls (PCBs) contamination in Kyeonggi Bay, Namyang Bay, and Lake Shihwa, 63 sediment samples were analyzed and applied to equilibrium partitioning approach. Sediment quality criteria (SQC) for exposure to Kanechlor mixture (KC-mix) was calculated as a value of 16 ${\mu}$g/g-organic carbon (OC). Two sites (Sites Kl8 and Kl9) within Incheon North Harbor (INH) with total PCBs concentrations 48 and 38 ${\mu}$g/g-OC, respectively, exceeded SQC, indicating a potential of adverse biological effects. The advantage and disadvantage of equilibrium partitioning approach has been discussed.

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Simulation of the Temperature and Salinity Along $36^{\circ}N$ in the Yellow Sea with a Wave-Current Coupled Model

  • Qiao, Fangli;Ma, Ji-An;Yang, Yong-Zeng;Yuan, Yeli
    • Journal of the korean society of oceanography
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    • 제39권1호
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    • pp.35-45
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    • 2004
  • Based on the MASNUM wave-current coupled model, the temperature and salinity structures along $36^{\circ}N$ in the Yellow Sea are simulated and compared with observations. Both the position and strength of the simulated thermocline are similar to data analysis. The wave-induced mixing is strongest in winter and plays a key role in the formation of the upper mixed layer in spring and summer. Numerical experiments suggest that in the coastal area, wave-induced mixing and tidal mixing control the vertical structure of temperature and salinity.

Heavy Metals In The Nagdong Estuary

  • Lee, Soo-Hyung;Lee, Dong-Soo;Kim, Eun-Soo;Kwak, Hi-Sang;Lee, Kwang Woo
    • 한국해양학회지
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    • 제16권1호
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    • pp.24-30
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    • 1981
  • In order to investigate water pollution of heavy metals in the Nagdong Estuary, samples were collected five times from August 1978 to April 1979 every other month, and analyzed for Cd, Cu, Pb and Zn by atomic absorption spectrophotometry. The results showed no significant heavy metal pollution in most parts of the studied areas, except near the outfalls of the Sasang Industrial Complex. In general, the heavy metal contents were higher in the dry season than in the rainy season due to the dilution effect of river water flow. Distribution of heavy metals in the dissolved and the particulate fractions were also investigated.

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Feasibility of Red Tide Detection around Korean Waters using Satellite Remote Sensing

  • Suh, Young-sang;Lee, Na-kyung;Lee, hyun-Jang;Kim, Hak-gyoon;Kim, Bok-kee;Hwang, Jae-dong
    • 한국어업기술학회:학술대회논문집
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    • 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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    • pp.129-131
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    • 2003
  • Korea has experienced a Cochlodinium polykrikoides red tide 10 out of the last 10 years (1993-2002). This species of red tide has been experienced at least once by all the southern coast of the Korean peninsular and has been transported up the southeastern coast all the way to the northeastern coast since 1995. The impression is that red tide is spending and becoming more common not only in the nearest coastal water, but also in the offshore. (omitted)

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The Studies on Remote Sensing and Their Applications of Islands and Offshore Region Features from IKONOS Images

  • Zhou, Changbao;Huang, Weigen;Zhang, Huaguo;Teng, Junhua;Li, Dongling;Xiao, Qingmei
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.123-125
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    • 2003
  • Satellite IKONOS images are one of important remote sensing data sources as today because of their very high spatial resolution. Their detections for islands and offshore oceanic features with multi-dimension and multi-scales information, specially some small islands, are of great potential. Their application abilities in islands and offshore detections are addressed at the first of the paper. And image processing technologies and the information extracting methodologies are described. Some results on remote sensing of the islands and their nearby object features are shown in details. Discussions and conclusions are carried out simply at the final.

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Tributyltin and Triphenyltin Residues in Pacific Oyster(Crassostrea gigas) and Rock Shell (Thais clavigera) from the Chinhae Bay System, Korea

  • Shin, Won-Joon;Oh, Jae-Ryoung;Kahng, Sung-Hyun;Shim, Jae-Hyung;Lee, Soo-Hyung
    • Journal of the korean society of oceanography
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    • 제33권3호
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    • pp.90-99
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    • 1998
  • Butyltin and phenyltin residues were quantified in seawater and biota of the Chinhae Bay System, Korea in 1995. Butyltin compounds were detected in all seawater and biota samples, whereas phenyltin compounds were found only in the biota samples. Tributyltin (TBT) concentrations in seawater ranged from < 8-35 ng Sn/l. Tributyltin concentrations in Crassostyea gigas and Thais clavigera ranged from 95-885 and 23-414 ng Sn/g, respectively, Triphenyltin(TPhT) concentrations in each species ranged 155-678 and 46-785 ng Sn/g, respectively. Spatial distribution of TBT was closely related to boating and dry-docking activities. However, spatial distribution of TPhT was not consistent with that of TBT. The biological concentration factor for TBT in C. gigas was about 25000 that is four times greater than that of T. clavigera. Butyl- to phenyltin concentration ratio was greater than one in C. gigas, but that in T. clavigera was less than one. Major tissues of C. gigas also showed different accumulation patterns for butyl- and phenyltin compounds. Furthermore, 19 and 28% of total body burdens of TBT and TPhT were found in gonadal mass of C. gigas just prior to spawning.

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The Occurrence of Glauconite Grains on the Continental Shelves off the Korean Peninsula: Distribution, Morphology and Origin

  • Lim, Dhong-Il;Park, Yong-Ahn;Cho, Ju-Whan;Choi, Jin-Yong
    • Journal of the korean society of oceanography
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    • 제34권2호
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    • pp.113-121
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    • 1999
  • Glauconite grains are widely distributed in the outer shelf surficial sandy sediments of the Korean continental shelves. Morphologically, these grains are characterized by ovoidal-shaped pellets with bulbous exterior, greenish color and moderately well polished surface. In thin sections, the glauconite grains are massive and contain numerous impurities composed mainly of quartz, feldspar and mica. The morphologies and microscopic examinations indicate mainly fecal pellet as a parent matierials for glauconite. SEM examination shows that glauconitic smectite crystals grow in pores and along fractures of the host grains, commonly as a boxwork arrangement or rosette clusters of blades. Bulbous external shape, high potassium content and rosette-shaped smectite structure, reflect the evolved stage (more than 10$^4$ years in age) of glauconite authigenesis. Moreover, the association of the glauconite grains with the relict sandy sediments on the outer shelf, impliesthat the glauconite grains are geologically old, or at least have formed under the environmental conditions different from the present shelf. The widespread occurrence of the glauconite grains, therefore, might be primarily related with redeposition of sediments transported from the outer shelf during Holocene transgression.

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Direct Observation of Radiative Flux in the Southern Yellow Sea

  • Lu, Lian-Gang;Yu, Fei;Diao, Xinyuan;Guo, Jingsong;Wang, Huiwu;Wei, Chuanjie
    • Ocean Science Journal
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    • 제43권2호
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    • pp.115-126
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    • 2008
  • Direct measurements of four radiative components at air-sea boundary layer were conducted in the southern Yellow Sea during three cruises (seasons) in 2007. Simultaneous observations of meteorological (cloud cover, air temperature and humidity) and oceanographic (sea surface temperature) parameters were carried out. Observational results of radiative fluxes and meteorological and oceanographic parameters are presented. Mean diurnal cycles of four radiative components, net radiation, and sea surface albedo are calculated to achieve averages in different seasons. Net radiative fluxes in three seasons (winter, spring, autumn) are 8, 146, $60\;W/m^2$, respectively. Comparisons between the observed radiative fluxes and those estimated with formulas are taken.

태풍에 의해 발생하는 한국근해 해황이상변동 (Abnormal Oceanic Conditions Caused by Typhoons Around the Korean Peninsula)

  • 서영상;구지영;황재동;이나경;김복기;장이현;강용균;이동인
    • 한국수산과학회지
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    • 제36권4호
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    • pp.417-429
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    • 2003
  • Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature (SST) in range of 5 to $8^{\circ}C$ was observed. The areas of SST decrease were an order of 100-200 km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30 m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.