• 제목/요약/키워드: antarctic research

검색결과 271건 처리시간 0.026초

남극, 킹조지섬, 세종과학기지 연안에 우점하는 남극암치아속 어류 두 종의 길이와 무게의 관계 (Length and Weight Relationship for Two Dominant Antarctic Notothenioid Fishes Caught in the Coastal Water off King Sejong Station, King George Island, Antarctica)

  • 박현;김일찬;강승현;김보미;한동원;김진형
    • 한국어류학회지
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    • 제29권2호
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    • pp.146-150
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    • 2017
  • 남극 연안에 우점하는 남극암치아목과, 암치아목속 어류 두 종 (Notothenia coriiceps와 Notothenia rossii)의 전장과 무게의 관계를 조사하였다. 어류는 2017년 1월에 남극 킹조지섬에 위치한 세종과학기지 연안에서 낚시로 채집되었다. 총 30마리가 채집된 N. coriiceps의 평균 전장은 266.0 mm였고, 7마리가 채집된 N. rossii의 평균전장은 275.4 mm이었다. 평균 무게의 경우 N. coriiceps는 283.1 g이었고, N. rossii는 290 g이었다. 전장과 무게의 관계를 조사한 결과, 두 종 모두 양의 상대성장 값(b>3)을 보였다. 본 조사에서 얻은 남극 연안에 우점하는 두 종의 크기 자료는 남극 해양생물의 환경적응 기작과 생물학적 대사과정을 이해하기 위한 관련 생리 연구를 수행하는데 있어서, 좋은 기초자료로 활용될 수 있을 것으로 기대된다.

Influence of microenvironment on the spatial distribution of Himantormia lugubris (Parmeliaceae) in ASPA No. 171, maritime Antarctic

  • Choi, Seung Ho;Kim, Seok Cheol;Hong, Soon Gyu;Lee, Kyu Song
    • Journal of Ecology and Environment
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    • 제38권4호
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    • pp.493-503
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    • 2015
  • This study analyzed how spatial distribution of Himantormia lugubris is affected by the microenvironment in the Antarctic Specially Protected Area (ASPA) No. 171 located in the Barton Peninsula of King George Island that belongs to the maritime Antarctic. In order to determine the population structure of H. lugubris growing in Baekje Hill within ASPA No. 171, we counted the individuals of different size groups after dividing the population into 5 growth stages according to mean diameter as follows: ≤ 1 cm, 1-3 cm, 3-5 cm, 5-10 cm, and ≥ 10 cm. The count of H. lugubris individuals in each growth stage was converted into its percentage with respect to the entire population, which yielded the finding that stages 1 through 5 accounted for 32.8%, 25.3%, 15.9%, 22.5%, and 3.5%, respectively. This suggests that the population of H. lugubris in ASPA No. 171 has a stable reverse J-shaped population structure, with the younger individuals outnumbering mature ones. The mean density of H. lugubris was 17.6/0.25 m2, mean canopy cover 13.3%, and the mean dry weight 37.8 g/0.25 m2. It began to produce spore in the sizes over 3 cm, and most individuals measuring 5-10 cm were adults with sexually mature apothecia. The spatial distribution of H. lugubris was highly heterogeneous. The major factors influencing its distribution and performance were found to be the period covered by snow, wind direction, moisture, size of the substrate, and canopy cover of Usnea spp. Based on these factors, we constructed a prediction model for estimating the spatial distribution of H. lugubris. Conclusively, the major factors for the spatial distribution of H. lugubris were snow, wind, substrate and the competition with Usnea spp. These results are important for understanding of the distribution in the maritime Antarctic and evolution of H. lugubris that claims a unique life history and ecological niche.

Isolation and Biochemical Characterization of Bacillus pumilus Lipases from the Antarctic

  • Arifin, Arild Ranlym;Kim, Soon-Ja;Yim, Joung Han;Suwanto, Antonius;Kim, Hyung Kwoun
    • Journal of Microbiology and Biotechnology
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    • 제23권5호
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    • pp.661-667
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    • 2013
  • Lipase-producing bacterial strains were isolated from Antarctic soil samples using the tricaprylin agar plate method. Seven strains with relatively strong lipase activities were selected. All of them turned out to be Bacillus pumilus strains by the 16S rRNA gene sequence analysis. Their corresponding lipase genes were cloned, sequenced, and compared. Finally, three different Bacillus pumilus lipases (BPL1, BPL2, and BPL3) were chosen. Their amino acid sequence identities were in the range of 92-98% with the previous Bacillus pumilus lipases. Their optimum temperatures and pHs were measured to be $40^{\circ}C$ and pH 9. Lipase BPL1 and lipase BPL2 were stable up to $30^{\circ}C$, whereas lipase BPL3 was stable up to $20^{\circ}C$. Lipase BPL2 was stable within a pH range of 6-10, whereas lipase BPL1 and lipase BPL3 were stable within a pH range of 5-11, showing strong alkaline tolerance. All these lipases exhibited high hydrolytic activity toward p-nitrophenyl caprylate ($C_8$). In addition, lipase BPL1 showed high hydrolytic activity toward tributyrin, whereas lipase BPL2 and lipase BPL3 hydrolyzed tricaprylin and castor oil preferentially. These results demonstrated that the three Antarctic Bacillus lipases were alkaliphilic and had a substrate preference toward short- and medium-chain triglycerides. These Antarctic Bacillus lipases might be used in detergent and food industries.

Surface Air Temperature Variations around the Antarctic Peninsula: Comparison of the West and East Sides of the Peninsula

  • Lee, Bang-Yong;Kwon, Tae-Yong;Lee, Jeong-Soon;Won, Young-In
    • Ocean and Polar Research
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    • 제24권3호
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    • pp.267-278
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    • 2002
  • This study investigated the spatial characteristics of warming trends and the dipole-like pattern of temperature field in the Antarctic Peninsula using surface air temperature (SAT) of 10 stations in the vicinity of the Antarctic Peninsula. SAT data for the 1962-2001 period at 6 stations (Rothera, Faraday/Vernadsky, Bellingshausen, Orcadas, Esperanza, Halley) revealed in general the larger warming trends in autumn and winter except for Halley. The largest warming was shown for August in the west side of the Peninsula (more than $0.9^{\circ}C/decade$). On the other hand, the recent 14-year SAT data showed the strong warming trends at 9 stations except for Halley in the earlier period (April-June) than August for the 1962-2001 period. The largest warming appeared in May at Esperanza and Butler Island. SAT of the two sides showed significant positive correlations over most of the period except for the mid- and the late 1970s, in which significant negative correlations were found. In the correlation analysis between SAT and sea surface temperature (SST) anomalies in the NINO 3.4 region, strong negative correlation was found in the west side of the Peninsula. Details of the correlation analysis exhibited that the negative correlation was significantly strong from the early 1980s to the mid-1990s. However, it was difficult to find significant correlations of ENSO with SAT in the east side of the Peninsula. So, in this study it failed to find out clearly the out-of-phase relationship of SAT across the Antarctic Peninsula.

극지 미생물들의 배양온도에 따른 성장률 및 protease activity 영향 연구 (Effect of Temperature on Growth Rate and Protease Activity of Antarctic Microorganisms)

  • 김현도;최종일
    • 한국미생물·생명공학회지
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    • 제42권3호
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    • pp.293-296
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    • 2014
  • 본 논문에서는 극지미생물의 저온 활성 protease 생산에 관한 연구를 수행하였다. 먼저 protease를 생산하는 극지미생물인 PAMC 25641, 25614, 25719, 25617을 16s rDNA 염기서열 분석을 이용하여 동정하였다. 그 후, 다양한 온도($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$)에서의 성장률 및 protease activity, specific activity를 확인하였다. 각 미생물의 온도별 성장률은 대체로 비슷한 경향을 보였으나 25617은 $20^{\circ}C$에서 급격한 성장률 증가를 확인할 수 있었다. 또한, specific activity는 25641이 5, 15, $20^{\circ}C$에서 가장 높은 specific activity를 갖는 것을 확인하였다.

고립지역의 풍력/디젤 복합발전 전력품질 특성 (The Power Quality about Wind/Diesel combined power generation in isolated area)

  • 고석환;김석우;이윤섭
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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    • pp.245-249
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    • 2009
  • Antarctic King Sejong Station was established in King George Island, the South Pole in 1988, and has been executing the monitoring studies on the change of antarctic natural environment. As an available power, the wind energy generator has been used in the form of hybrid with mainly diesel generator. Because the wind generation power sharply changes by wind energy, it must be careful during the system operation. When the power system becomes stable, the output performance of wind energy generator becomes stable. But, in case of unstable system, the errors frequently occur on the wind energy generator and it badly impacts the power system by output of wind energy generator. The purpose of this paper is to analyze suitability while operating the system of 10kW wind energy generator at Antarctic King Sejong Station, an isolated area, and to analyze the problem and improvements by power quality.

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남극 및 시베리아 흙의 동토공학적 특성 분석 (Engineering Characteristics of Antarctic and Siberian Frozen Soils)

  • 김영진;신재원;김현기
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.894-904
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    • 2008
  • In this study, soil samples from the Antarctic and Vladivostok, Siberia were tested in the laboratory, and specific gravity, compaction curve and grain size distribution were determined. The effect of temperature change on the thermal conductivity, unfrozen water content and compressive strength were investigated. Samples for the compressive strength test were prepared in a mold with a fixed volume to prevent swelling and the effect of temperature and water content change on the strength were compared. Results from the thermal conductivity test showed that thermal conductivity values for both soils were larger at temperatures below freezing than above freezing. The unfrozen water content dropped sharply within a temperature range of $0{\sim}-5^{\circ}C$ and then gradually decreased further up to $-20^{\circ}C$. Compressive strength test results showed various stress/deformation curves with a change in water content. Sandy soil had much larger strength than pure ice at an identical temperature, while clayey soil had a smaller strength than ice near the freezing point, but showed a larger strength at temperatures belows $-15^{\circ}C$.

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Climatological Trend of Sea Water Temperature around the Antarctic Peninsula Waters in the Southern Ocean

  • Lee, Chung-Il;Kim, Sang-Woo;Kim, Dong-Sun;Yoon, Moon-Geun
    • 한국환경과학회지
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    • 제21권2호
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    • pp.125-133
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    • 2012
  • Climatological trend for the period of 1970 to 2009 in sea water temperature around the Antarctic Peninsular waters in the Southern Ocean was investigated. During the period from 1970 to 2009, sea water temperature in the top 500 m water column except 100 m increased at a rate of $0.003-0.011^{\circ}C{\cdot}yr^{-1}$, but at 100 m it decreased at a rate of $-0.003^{\circ}C{\cdot}yr^{-1}$. Although long-term trend is generally warming, there were several periods of sharp changes between 1970 and 2009. Annual mean sea water temperature between surface and 500 m except 100 m decreased from the early of 1970s to the end of 1980s, and then it increased to the end of 2000s. In the entire water column between the surface and 500 m, sea water temperature closely correlated with the El Nino events expressed as the Southern Oscillation Index(SOI), and SOI and sea water temperature have a dominant period of about 3-5 years and decade.

Ecological and Biogeochemical Response of Antarctic Ecosystems to Iron Fertilization and Implications on Global Carbon Cycle

  • Bathmann, Ulrich
    • Ocean and Polar Research
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    • 제27권2호
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    • pp.231-235
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    • 2005
  • The European Iron Fertilization Experiment EIFEX studied the growth and decline of a phytoplankton bloom stimulated by fertilising $10km^2$ in the core of a mesoscale $(80{\times}120km)$ cyclonic eddy south of the Antarctic Polar Front with about 2 times 7 tonnes of iron sulphate. The phytoplankton accumulation induced by iron fertilization did not exceed $3{\mu}g\;chl\;a\;l^{-1}$ despite a draw down of $5{\mu}M$ of nitrate that should have resulted in at least double to triple the amount of phytoplankton biomass assuming regular Redfield-ratios for draw down after phytoplankton growth in the Southern Ocean. During EIFEX the fertilized core of the mesoscale eddy evolved to a hotspot for a variety of small and medium sized mesozooplankton copepods. In contrast to copepods, the biomass of salps (Salpa thompson)) that dominated zooplankton biomass before the onset of our experiment decreased to nearly extinction. Most of the species of the rnosozooplankton community showed extremely hiか feeding rates compared to literature values from Southern Ocean summer communities. At the end of the experiment, massive phytoplankton sedimentation reached the sea floor at about 3800m water depth.