• 제목/요약/키워드: tide

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The Coastline Extraction Using RTK GPS/GLONASS

  • Jang, Ho-Sik;Roh, Tae-Ho;Lee, Jong-Chool
    • Korean Journal of Geomatics
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    • v.2 no.2
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    • pp.107-113
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    • 2002
  • On this study, it was applied that the method of Coastline extracting by aerial photogrammetry so as to extract the coastline using the method of RTK GPS/GLONASS. The observed area is Gwanganri beach that is located in Pusan and it was observed according to high wave of scar when the approximate highest high water and it was surveyed according to that the boundary line connecting to sea water surface at random time-zone. Observation analysis was used digital map of 1:1,000 and compared coastline that was converted tide with coastline of high tide. So this conclusions was agreed with converted coastline and high tide coastline.

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The Characteristics on the Mixing of Freshwater in Suyoung Bay (수영만의 담${\cdot}$염수의 혼합특성에 관한 연구)

  • PARK Cheol-Suck;KIM Jong-Kyu;CHANG Sun-Duck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.26 no.4
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    • pp.353-362
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    • 1993
  • Behaviors of effulent are observed and discussed with reference to the tide and freshwater discharge in the estuary of Suyoung Bay. The esturine front is located at $0.5{\sim}1.3km$ seaward from of the Suyoung Bridge at the spring tide, and $0.8{\sim}1.0km$ at the neap tide. After the heavy precipitations, the front moved seaward and was located at $1.3{\sim}2.5km$ southeast of the Suyoung Bridge. Internal Froude numbers in the estuarine salinity front are estimated approximately to be 1 both at the spring and neap tide. Entrainment coefficient decreases down stream to the estuarine front, and then increases seaward from the estuarine front due to the tidal mixing.

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Realtime Tide and Storm-Surge Computations for the Yellow Sea Using the Parallel Finite Element Model (병렬 유한요소 모형을 이용한 황해의 실시간 조석 및 태풍해일 산정)

  • Byun, Sang-Shin;Choi, Byung-Ho;Kim, Kyeong-Ok
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.1
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    • pp.29-36
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    • 2009
  • Realtime tide and storm-surge computations for the Yellow Sea were conducted using the Parallel Finite Element Model. For these computations a high resolution grid system was constructed with a minimum node interval of loom in Gyeonggi Bay. In the modeling, eight main tidal constituents were analyzed and their results agreed well with the observed data. The realtime tide computation with the eight main tidal constituents and the storm-surge simulation for Typhoon Sarah(1959) were also conducted using parallel computing system of MPI-based LINUX clusters. The result showed a good performance in simulating Typhoon Sarah and reducing the computation time.

A Study on the Detection Method of Red Tide Area in South Coast using Landsat Remote Sensing (Landsat 위성자료를 이용한 남해안 적조영역 검출기법에 관한 연구)

  • Sur, Hyung-Soo;Song, In-Ho;Lee, Chil-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.129-141
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    • 2006
  • The image data amount is increasing rapidly that used geography, sea information etc. with great development of a remote sensing technology using artificial satellite. Therefore, people need automatic method that use image processing description than macrography for analysis remote sensing image. In this paper, we propose that acquire texture information to use GLCM(Gray Level Co-occurrence Matrix) in red tide area of artificial satellite remote sensing image, and detects red tide area by PCA(principal component analysis) automatically from this data. Method by sea color that one feature of remote sensing image of existent red tide area detection was most. but in this paper, we changed into 2 principal component accumulation images using GLCM's texture feature information 8. Experiment result, 2 principal component accumulation image's variance percentage is 90.4%. We compared with red tide area that use only sea color and It is better result.

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Nitrate uptake of the red tide dinoflagellate Prorocentrum micans measured using a nutrient repletion method: effect of light intensity

  • Lee, Kyung Ha;Jeong, Hae Jin;Kim, Hye Jeong;Lim, An Suk
    • ALGAE
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    • v.32 no.2
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    • pp.139-153
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    • 2017
  • The ability of a red tide species to take up nutrients is a critical factor affecting its red tide dynamics and species competition. Nutrient uptake by red tide species has been conventionally measured by incubating nutrient-depleted cells for a short period at 1 or 2 light intensities. This method may be applicable to certain conditions under which cells remain in oligotrophic water for a long time and high nutrients are suddenly introduced. Thus, a new method should be developed that can be applicable to the conditions under which cells are maintained in eutrophicated waters in healthy conditions and experience light and dark cycles and different light intensities during vertical migration. In this study, a new repletion method reflecting these conditions was developed. The nitrate uptake rates of the red tide dinoflagellate Prorocentrum micans originally maintained in nitrate repletion and depletion conditions as a function of nitrate concentration were measured. With increasing light intensity from 10 to $100{\mu}E\;m^{-2}s^{-1}$, the maximum nitrate uptake rate ($V_{max}$) of P. micans increased from 3.6 to $10.8 pM\;cell^{-1}d^{-1}$ and the half saturation constant ($K_{s-NO3}$) increased from 4.1 to $6.9{\mu}M$. At $20{\mu}E\;m^{-2}s^{-1}$, the $V_{max}$ and $K_{s-NO3}$ of P. micans originally maintained in a nitrate repletion condition were similar to those maintained in a nitrate depletion condition. Thus, differences in cells under nutrient repletion and depletion conditions may not affect $K_{s-NO3}$ and $V_{max}$. Moreover, different light intensities may cause differences in the nitrate uptake of migratory phototrophic dinoflagellates.

Cross-Sectional Velocity Variability and Tidal Exchanger in a Bay (만구를 통한 해수유출입과 만내수괴의 해수교환성)

  • 김종화
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.4
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    • pp.353-359
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    • 1990
  • Chinhae Bay, included small ports, is the region which the red tide phenomenon is occurred frequently in summer season. Field sampling of 4 cross-sections in the bay resulted in detailed informations on cross-sectional velocity distributions, salt concentrations and discharge during one consecutive tidal cycle in summer season, 1983. High velocity cores reoccur two times a semi-diurnal tidal cycle at the same cross-sectional location, lower layer, in Kadok Channel during the spring tide. The tidal exchange ratio was estimated by Eulerian method. The range of exchange ratios in central Kadok Channel are 9.3-17% at the spring tide and 16.9-21.8% at the neap tide. On the other hand, its range in Masan bay-mouth is 8.7% at the spring tide and 2.0% neap tide, respectively.

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Estimating Ocean Tidal Constituents Using SAR Interferometric Time Series over the Sulzberger Ice Shelf, W. Antarctica

  • Baek, Sang-Ho;Shum, C.K.
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.5
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    • pp.343-353
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    • 2018
  • Ocean tides in Antarctica are not well constrained mostly due to the lack of tidal observations. Especially, tides underneath and around ice shelves are uncertain. InSAR (Interferometric Synthetic Aperture Radar) data has been used to observe ice shelf movements primarily caused by ocean tides. Here, we demonstrate that it is possible to estimate tidal constituents underneath the Sulzberger ice shelf, West Antarctica, solely using ERS-1/2 tandem mission DInSAR (differential InSAR) observations. In addition, the tidal constituents can be estimated in a high-resolution (~200 m) grid which is beyond any tidal model resolution. We assume that InSAR observed ocean tidal heights can be derived after correcting the InSAR data for the effect of atmospheric loading using the inverse barometric effect, solid earth tides, and ocean tide loading. The ERS (European Remote Sensing) tandem orbit configuration of a 1-day separation between SAR data takes diminishes the sensitivity to major tidal constituents including $K_1$ and $S_2$. Here, the dominant tidal constituent $O_1$ is estimated using 8 differential interferograms underneath the Sulzberger ice shelf. The resulting tidal constituent is compared with a contemporary regional tide model (CATS2008a) and a global tide model (TPXO7.1). The InSAR estimated tidal amplitude agrees well with both models with RMS (root-mean-square) differences of < 2.2 cm and the phase estimate corroborating both tide models to within $8^{\circ}$. We conclude that fine spatial scale (~200 m) Antarctic ice shelf ocean tide determination is feasible for dominant constituents using C-band ERS-1/2 tandem mission InSAR.

Removal and Growth Inhibition of Red-tide Organisms by Blue-Min Treatment (블루민의 적조생물 제거와 생장저해능)

  • Gwak, Seung-Kuk;Jung, Min-Kyung;Lee, Eun-Ki;Cho, Kyung-Je
    • ALGAE
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    • v.19 no.1
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    • pp.7-14
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    • 2004
  • Blue-Min was initially developed as an adsorbent for harmful gas removal and recently improved to apply to livestock, agriculture and aquaculture as an assistant feed. In the Blue-Min treatment, growth of harmful algae (Cochlodinium polykrikoides and the others causing the red-tide in the ocean) were inhibited below 10% in comparison with control and coagulation removal of harmful alge with Blue-Min treatment was more efficient than that of yellow loess treatment. It would be expected that the Ble-Min can be useful for the extirpator against the red-tide organisms and restrain the toxic algal growth around the fish aquaculture using the assistant feed. Recently, its utility has become to be diverse as it was revealed that aquaculture productivity increase by its application and, in addition, that it improve the water quality or sediment conditions in the aquaculture of Chinese White Shrimp. When Blue-Min was treated with the proper dose, the growth inhibition of Microcystis aeruginosa and lsochrysis galbana, which are typical red-tide organisms in freshwaters and food organisms in aquaculture, respectively, were less than that of marine red-tide organisms, while their growth slightly increased with low concentration treatiment. In addition, polyunsaturated fatty acids (PUFA) content of I. galbana slightly increase with the Blue-Min treatment. Through our research, the Blue-Min has diverse and comples function against various biological organisms and is proved as a biological activator or depressor.

The Response of Temperature and Velocity Fields to $M_2$ Tide in Deukryang Bay in the Southern Sea of Korea (득량만에서의 $M_2$조에 대한 수온장 및 유속장의 응답)

  • HONG Chul-hoon;CHOI Yong-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.4
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    • pp.667-678
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    • 1997
  • A primitive equation numerical model driven only by $M_2$ tide is used to examine role of tide in the temperature and velocity fields of Deukryang Bay. The numerical model reproduces several features of the observational temperature fields such that the isotherms tend to be parallel to the coast in the bay, and the colder water exists at the right hand side in the bay. The horizontal temperature and velocity fields in the model are dominantly influenced by bottom topography. The model also shows that the surface colder water in the bay is accompanied by strong-alongshore current during the flood tide. An investigation for baroclinicity in the bay by additional numerical experiment indicates that the baroclinirity in velocity field is very weak. The model, however, did not reproduce a stratification in the observation, implying that the model needs to add other semi-diurnal components such as $S_2,\;O_2\;or\;K_2$ tides to $M_2$ tide.

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