• Title/Summary/Keyword: Atlantic Ocean

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Genetic Distances Within-Population and Between-Population of Tonguesole, Cynoglossus spp. Identified by PCR Technique

  • Yoon, Jong-Man
    • Development and Reproduction
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    • v.23 no.3
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    • pp.297-304
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    • 2019
  • The higher fragment sizes (>2,100 bp) are not observed in the two C. spp. populations. The six oligonucleotides primers OPA-11, OPB-09, OPB-14, OPB-20, OPC-14, and OPC-18 were used to generate the unique shared loci to each tonguesole population and shared loci by the two tonguesole populations. The hierarchical polar dendrogram indicates two main clusters: Gunsan (GUNSAN 01-GUNSAN 11) and the Atlantic (ATLANTIC 12-ATLANTIC 22) from two geographic populations of tonguesoles. The shortest genetic distance displaying significant molecular difference was between individuals' GUNSAN no. 02-GUNSAN no. 01 (genetic distance=0.038). In the long run, individual no. 02 of the ATLANTIC tonguesole was most distantly related to GUNSAN no. 06 (genetic distance=0.958). These results demonstrate that the Gunsan tonguesole population is genetically different from the Atlantic tonguesole population. The potential of PCR analysis to identify diagnostic markers for the identification of two tonguesole populations has been demonstrated. As a rule, using various oligonucleotides primers, this PCR method has been applied to identify polymorphic/specific markers particular to species and geographical population, as well as genetic diversity/polymorphism in diverse species of organisms.

Sexual Reproduction in Audouinella alariae (Jonsson) Woelkerling (Acrochaetiaceae, Rhodophyta) from the North Atlantic Ocean (북대서양산 Aubouinella alariae (Jonsson) Woelkerling의 유성생식)

  • LEE Yong-Pil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.3
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    • pp.265-272
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    • 1983
  • Carpogonia, spermatangia and carposporangia are demonstrated for North Atlantic plants of Audouinella alariae (Jonsson) Woelkerling for the first time. The plants are monoecious. Carpogonia are terminal on short branches and give rise to short trichogynes laterally. Spermatangia are usually borne in pairs on the supporting cells of carpogonia. Fertilized carpogonia give rise to 3-4 carposporangia. Morphology of sexual reproductive structures and postfertilization development provide characteristics for distinguishing A. alariae from A. rhipidandra (Rosenvinge) Dixon, which were previously synonymized.

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Analysis of Tropical Tropospheric Ozone Derivation from Residual-Type Method

  • Na Sun-Mi;Kim Jae-Hwan
    • Korean Journal of Remote Sensing
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    • v.22 no.1
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    • pp.1-10
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    • 2006
  • During the northern burning season, biomass burning is found north of the equator, while satellite estimates from the residual-type method such as the CCD method show higher ozone south of the equator. This discrepancy is called the tropical Atlantic paradox (Thompson et ai., 2000). We use satellite and ground-based measurements to investigate the paradox. When the background tropospheric ozone over the Pacific Ocean from TOMS measurements is subtracted from the latitudinal total ozone distribution (e.g. TOMS-Pacific method), the results show remarkable agreement with the latitudinal stratospheric ozone distribution using the CCD method. The latitudinal tropospheric ozone distribution using the CCD method, with a persistent maximum over the southern tropical Atlantic, is also seen in the latitudinal tropospheric ozone distribution using the TOMS-Pacific method. It suggests that the complicated CCD method can be replaced by the simple TOMS-Pacific method. However, the tropical Atlantic paradox exists in the results of both the CCD and TOMS-Pacific methods during the northern buming season. In order to investigate this paradox, we compare the latitudinal ozone distributions using the CCD and TOMS-Pacific methods by using the SAGE measurements (e.g. TOMS-SAGE method) and the SHADOZ ozonesoundings (e.g. TOMS-Sonde method) assuming zonally invariant stratospheric ozone, which is the same assumption as of the CCD method. During the northern burning season, the latitudinal distributions in the tropospheric ozone derived from the TOMS-SAGE and TOMS-Sonde methods show higher tropospheric ozone over the northern tropical Atlantic than the southern Atlantic due to a stronger gradient in stratospheric ozone relative to that from the CCD and TOMS-Pacific methods. This indicates that the latitudinal tropospheric ozone distribution can be changed depending on the data that is used to determine the latitudinal stratospheric ozone distribution. Therefore, there is a possibility that the north-south gradient in stratospheric ozone over the Atlantic can be a solution of the paradox.

Application of the Indirect Effect on Regional Gravith Fielcs in the North Atlantic Ocean (北大西洋 重力場에 적용한 Indirect Effect)

  • 정우열;필립로
    • 한국해양학회지
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    • v.22 no.1
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    • pp.19-24
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    • 1987
  • Gravity measurements at sea are considered to be made on the geoid. The free-air anomalies are then determined by subtracting the theoretical gravity values predicted on a reference ellipsoid from the observed values. The gravity effect due to the height difference between the geoid and reference ellipsoid and the mass between them is known as the 'indirect effect'. The result of applying the indirect effect to surface ship derived gravity anomalies in the North Atlantic Ocean demonstrates the importance of its inclusion for regional stuedies involving mantle processes.

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Effects of Environmental Changes on Stock of Krill and Salp in the Atlantic and Indian Sectors of the Antarctic

  • Lee, Chung-Il;Pakhomov, E.A.;Atkinson, Angus;Siegel, Volker
    • Fisheries and Aquatic Sciences
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    • v.10 no.4
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    • pp.215-219
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    • 2007
  • Long-tenn variation in krill (Euphausia superba) and salp (mainly Salpa thompsoni) stocks was compared to environmental changes in the Atlantic and Indian sectors of the Antarctic. Environmental conditions examined were air temperature, water temperature, salinity, and sea-ice extent from 1926 to 1938 and from 1982 to 2000. The long-term pattern of krill was opposite to that of salp: krill stock decreased while salp stock increased concurrently. Krill stock was about three-fold higher from 1926 to 1938 than from 1982 to 2000, but salp was about four -fold lower in 1926-1938 than in 1982-2000. A wanning trend was observed in the environmental data, and the long-term variation in krill and salp stocks was affected by this trend.

DURABILITY TESTING OF MARINE REINFORCED CONCRETE UNDER FATIGUE LOADING, PART I AND II (피로하중을 받는 해양 콘크리트의 내구성 연구)

  • ;D. V. Reddy
    • Proceedings of the Korea Concrete Institute Conference
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    • 1996.04a
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    • pp.348-353
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    • 1996
  • This study addresses the evaluation of the durability of reinforced concrete marine structures subjected to fatigue loading. The laboratory investigation was carried out on full and half size reinforced concrete specimens with three different water cement ratios (0.3, 0.4, and 0.56), static and fatigue loading conditions, and epoxy-coated and regular black steel reinforcements. The marine tidal zone was simulated by alternate filling and draining of the tank (wet and dry cycled), and a galvanostatic corrosion technique to accelerate corrosion of reinforcement was used. Half-cell potentials and changes of crack width were measured periodically during the exposure and followed by ultimate strength testing. The significant findings include adverse effect of fatigue loading, existence of an explicit size effect, poor performance of epoxy coated steel, and negative effect of increasing water/cement ratio.

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Ocean Response to the Pinatubo and 1259 Volcanic Eruptions

  • Kim, Seong-Joong;Kim, Baek-Min
    • Ocean and Polar Research
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    • v.34 no.3
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    • pp.305-323
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    • 2012
  • The ocean's response to the Pinatubo and 1259 volcanic eruptions was investigated using an ocean general circulation model equipped with an energy balance model. Volcanic eruptions release gases into the atmosphere which increases the aerosol optical depth and acts to reduce the incoming short-wave radiation. For example, there was a huge volcanic eruption (Pinatubo) in 1991 which reduced the global mean radiative forcing by about 3 W $m^{-2}$. Two numerical experiments were simulated. The first experiment features the Pinatubo eruption and the second experiment simulates the much larger volcanic eruption that occurred in 1259 when the radiative forcing was reduced by 7 times compared to the Pinatubo event. With the reduced radiative forcing due to the Pinatubo eruption at about 3 W $m^{-2}$ and 1259 eruption at about 21 W $m^{-2}$, the global mean sea surface temperature (SST) decreased to its lowest in the second year after each event by about $0.4^{\circ}C$ and $1.6^{\circ}C$, respectively. Sea surface salinity (SSS) increased substantially in the northern North Pacific, northern North Atlantic, and the Southern Ocean. The reduced SST together with SSS increased ocean convection, which yielded an increase in North Atlantic Deep Water, Antarctic Bottom Water, and North Pacific Intermediate Water production and their outflows. The increase in overturning circulation eventually increased the pole-ward ocean heat fluxes. In conclusion, huge volcanic eruptions perturb the ocean substantially and their hallmarks last for more than a decade, confirming the importance of volcanic eruptions in illustrating the decadal-climate variability recorded in the paleoclimate proxy data for the past million years.