• Title/Summary/Keyword: antarctica

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Power Quality of Wind/Diesel Hybrid Operation at an Micro Grid (마이크로 그리드에서의 풍력/디젤 복합발전 전력품질)

  • Kim, Seok-Woo;Ko, Seok-Whan;Jand, Moon-Seok
    • Journal of the Korean Solar Energy Society
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    • v.29 no.4
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    • pp.41-47
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    • 2009
  • Wind/diesel hybrid operation can be one of the most effective option for electrical power production at a remote area such as Antarctica. The king Sejong station at Antarctica relies its power production on diesel engines and diesel oil is supplied every other year by ships. However, the oil transportation processes are liable to potential oil spillage caused by the floating ice around the King George island. The long-term storage of the oil at the station can also contaminate the surrounding soils. A l0kW wind turbine has been installed to save oil consumption and operated in connection with the diesel generators since 2006. The diesel engine that operated poorly during the first year of installation was replaced in 2008 to enhance power production an recent measurements indicate that both diesel power quality and the wind turbine availability have been dramatically improved by the replacement. This report discusses electrical power qualities of wind/diesel hybrid system operating at an isolated micro gird located in the king Sejong station. Our experience reveals that the similar technologies can be applied to domestic islands, for example, in the south sea.

GPR Investigation of Glacier on Livingstone Island, Antarctica (GPR을 이용한 리빙스톤섬 빙하층 탐사)

  • Lee, Joo-Han;Jin, Young-Keun;Hong, Jong-Kuk;Hong, Sung-Min;Kim, Yea-Dong
    • Journal of the Korean Geophysical Society
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    • v.8 no.2
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    • pp.63-66
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    • 2005
  • With the aim of global environmental monitoring we carried out GPR (Ground Penetrating Radar) surveys at the Livingstion Island in Antarctica. Research area is near the Mt. Charra (340 m) in Livingston Island which is located 80 km to the southwest of the King Sejong Station. We have collected 5 lines of GPR data. Two kinds of survey, CMP (Common Midpoint) surveys and common offset profiles, were performed. We classified the glacier into the three layers using electromagnetic velocity of the ice and reflection characteristic. The depth of glacier reached about 80∼110 m. Some reflectors showed the evidence of the water filled englacial drainage and volcanic ash-layers.

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Bibliometric Analysis of Collaboration Network and the Role of Research Station in Antarctic Science

  • Kim, Hyunuk;Jung, Woo-Sung
    • Industrial Engineering and Management Systems
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    • v.15 no.1
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    • pp.92-98
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    • 2016
  • Due to the large scale of Antarctic science, scientific collaboration is required for conducting scientific research. In this study, we attempted to investigate collaboration network and the role of research station in Antarctic science based on bibliometric data from 1995 to 2014. We confirmed that geographical proximity tends to be important for scientific collaboration by employing community detection in the network. This result raises the question about what the role of research station in Antarctica is. We tried to reveal its role by focusing on five countries, Belgium, China, Czech Republic, India, and Korea that constructed new research stations during the last decade. Relative growth rate, a value to measure the growth of publications, didn't differ much around the construction period compared to those in other periods for these countries except Belgium. However, we found geographical keywords emerged around the construction for all five countries. These keywords were utilized to observe national research activities in Antarctica. They show where countries started to be concerned about after the construction.

Flow Velocity Change of David Glacier, East Antarctica, from 2016 to 2020 Observed by Sentinel-1A SAR Offset Tracking Method

  • Moon, Jihyun;Cho, Yuri;Lee, Hoonyol
    • Korean Journal of Remote Sensing
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    • v.37 no.1
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    • pp.1-11
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    • 2021
  • This study measures the change of ice flow velocity of David Glacier, one of the fast-moving glaciers in East Antarctica that drains through Drygalski Ice Tongue. In order to effectively observe the rapid flow velocity, we applied the offset tracking technique to Sentinel-1A SAR images obtained from 2016 to 2020 with 36-day temporal baseline. The resulting velocity maps were averaged and the two relatively fast points (A1 and A2) were selected for further time-series analysis. The flow velocity increased during the Antarctic summer (around December to March) over the four years' observation period probably due to the ice surface melting and reduced friction on the ice bottom. Bedmap2 showed that the fast flow velocities at A1 and A2 are associated with a sharp decrease in the ice surface and bottom elevation so that ice volumetric cross-section narrows down and the crevasses are being created on the ice surface. The local maxima in standard deviation of ice velocity, S1 and S2, showed random temporal fluctuation due to the rotational ice swirls causing error in offset tracking method. It is suggested that more robust offset tracking method is necessary to incorporate rotational motion.

Responses of the Ross Sea to the Climate Change: Importance of observations in the Ross Sea, Antarctica (기후변화에 따른 남극 로스해 반응에 관한 고찰: 남극 로스해 관측의 중요성)

  • Yoon, Seung-Tae
    • Ocean and Polar Research
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    • v.44 no.1
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    • pp.69-82
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    • 2022
  • The Ross Sea, Antarctica plays an important role in the formation of Antarctic Bottom Water (AABW) which is the densest water mass in global thermohaline circulation. Of the AABW, 25% is formed in the Ross Sea, and sea ice formation at the polynya (ice-free area) developed in front of ice shelves of the Ross Sea is considered as a pivotal mechanism for AABW production. For this reason, monitoring the Ross Sea variations is very important to understand changes of global thermohaline circulation influenced by climate change. In addition, the Ross Sea is also regarded as a natural laboratory in investigating ice-ocean interactions owing to the development of the polynya. In this article, I introduce characteristics of the Ross Sea described in previous observational studies, and investigate variations that have occurred in the Ross Sea in the past and those taking place in the present. Furthermore, based on these observational results, I outline variations or changes that can be anticipated in the Ross Sea in the future, and make an appeal to researchers regarding the importance and necessity of continuous observations in the Ross Sea.

Distribution characteristics of Antarctic silverfish (Pleuragramma antarcticum) in the Ross Sea, Antarctica (남극 로스해에 서식하는 남극 은암치(Pleuragramma antarcticum)의 분포 특성)

  • Sara LEE;Wooseok OH;Hyoungsul LA;Wuju SON;Jeong-Hoon KIM;Kyounghoon, LEE
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.2
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    • pp.117-124
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    • 2023
  • This study used hydroacoustic method to identify the vertical and horizontal distribution of Antarctic silverfish in the Ross Sea, Antarctica. In February and December 2018, Antarctic silverfish was detected up to 250 meters, and was mainly distributed in water depths of 20 to 30 meters. The horizontal distribution of Antarctic silverfish was mostly undetected in February, and December showed a relatively stronger distribution than that of February. Antarctic silverfish is characterized by their distribution near sea ice.

Diversity and Physiological Characteristics of Culturable Bacteria from Marine Sediments of Ross Sea, Antarctica (남극 로스해 퇴적물로부터 분리된 세균의 다양성 및 생리학적 특성)

  • Lee, Yung Mi;Jung, You-Jung;Hong, Soon Gyu;Kim, Ji Hee;Lee, Hong Kum
    • Korean Journal of Microbiology
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    • v.50 no.2
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    • pp.119-127
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    • 2014
  • The affiliations and physiological characteristics of culturable bacteria isolated from the sediments of Ross Sea, Antarctica were investigated. Sixty-three isolates obtained by cultivation were grouped into 21 phylotypes affiliated with the phyla Actinobacteria and Bacteroidetes and with the classes Alphaproteobacteria and Gammaproteobacteria by phylogenetic analysis of 16S rRNA gene sequences. Based on phylogenetic analysis (<98.65% sequence similarity), approximately 49% of total isolates represented potentially novel species or genus. Among them, extracellular protease, lipase, and exopolysaccharide activities at $10^{\circ}C$ or $20^{\circ}C$ were detected in approximately 46%, 25%, and 32% of the strains, respectively. Forty-three isolates produced at least one type of extracellular material and 21 of them produced at least two extracellular protease, lipase, and/or exopolysaccharides. Our findings indicate that culturable bacterial diversity present within the marine sediments of Ross Sea, Antarctica may contribute to the hydrolysis of the major organic constituents which is closely related with carbon and nitrogen cycling in this environment.

Holocene Glaciomarine Sedimentation in Marian Cove, King George Island, West Antarctica (서 남극 킹조지 섬 마리안 소만의 홀로세 빙해양 퇴적작용)

  • Chang, Soon-Keun;Yoon, Ho-Il
    • Journal of the Korean earth science society
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    • v.21 no.3
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    • pp.276-286
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    • 2000
  • A 2.3 m-long core obtained from Marian Cove, King George Island in the South Shetland Islands, West Antarctica shows clues to the glaciomarine sedimentation during the Holocene. The lower part below 115cm-deep of the core is predominated by coarser material such as diamictons compared with the higher part above 105cm dominated by finer material (rhythmite and massive muds). Based on the granulometric features the coarse materials are generally supposed to be glacially-driven and basal tills, whereas the fine materials appear to originate from various sources such as meltwater-supplied, glacially-supplied, wind-blown, and organic origins. However, the presence of erratic coarse particles in the finer materials suggests the ice-rafted origin of the relevant materials. The lower part below 105cm-deep of the core was characterized by lower TN, TC, and TOC contents, and by higher TS and CaCO$_3$ contents compared with its upper part. No significant changes in C/N ratio were shown throughout the core. The ice cliff along the east side of Marian Cove seemed to locate to the west by 1.6km at 8,300 years B. P. on the basis of the repetitive occurrence of rhythmite and diamicton. Since the retreat of ice cliff in 7,970${\pm}$70 years B. P. the sediments of Marian Cove were dominated by fine materials and ice-rafted materials. The abrupt increase of coarse materials in 175cm-4 deep seems to result from supply of coarse materials due to earthquake or other drastic phenomena.

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A Numerical Simulation Study of Strong Wind Events at Jangbogo Station, Antarctica (남극 장보고기지 주변 강풍사례 모의 연구)

  • Kwon, Hataek;Kim, Shin-Woo;Lee, Solji;Park, Sang-Jong;Choi, Taejin;Jeong, Jee-Hoon;Kim, Seong-Joong;Kim, Baek-Min
    • Atmosphere
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    • v.26 no.4
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    • pp.617-633
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    • 2016
  • Jangbogo station is located in Terra Nova Bay over the East Antarctica, which is often affected by individual storms moving along nearby storm tracks and a katabatic flow from the continental interior towards the coast. A numerical simulation for two strong wind events of maximum instantaneous wind speed ($41.17m\;s^{-1}$) and daily mean wind speed ($23.92m\;s^{-1}$) at Jangbogo station are conducted using the polar-optimized version of Weather Research and Forecasting model (Polar WRF). Verifying model results from 3 km grid resolution simulation against AWS observation at Jangbogo station, the case of maximum instantaneous wind speed is relatively simulated well with high skill in wind with a bias of $-3.3m\;s^{-1}$ and standard deviation of $5.4m\;s^{-1}$. The case of maximum daily mean wind speed showed comparatively lower accuracy for the simulation of wind speed with a bias of -7.0 m/s and standard deviation of $8.6m\;s^{-1}$. From the analysis, it is revealed that the each case has different origins for strong wind. The highest maximum instantaneous wind case is caused by the approach of the strong synoptic low pressure system moving toward Terra Nova Bay from North and the other daily wind maximum speed case is mainly caused by the katabatic flow from the interiors of Terra Nova Bay towards the coast. Our evaluation suggests that the Polar WRF can be used as a useful dynamic downscaling tool for the simulation and investigation of high wind events at Jangbogo station. However, additional efforts in utilizing the high resolution terrain is required to reduce the simulation error of high wind mainly caused by katabatic flow, which is received a lot of influence of the surrounding terrain.

Sea Ice Detection using Microwave Remote Sensing Techniques in the Weddell Sea, Antarctica (마이크로웨이브 원격탐사를 이용한 남극 웨델해 해빙 관측)

  • 황종선;이방용;심재설;홍성민;윤호일;권태영;민경덕;김정우
    • Economic and Environmental Geology
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    • v.36 no.2
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    • pp.141-148
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    • 2003
  • We investigated the distribution of sea ice using various microwave remote sensing techniques including radar altimeter, radiometer, and scatterometer data in the part of Drake passage, Antarctica, between the area 45$^{\circ}$-75$^{\circ}$W and 55$^{\circ}$-66$^{\circ}$S. Topex/poseidon radar altimeter data were used to analyze the monthly distribution of sea ice surface area between 1992 and 1999 by using Geo_bad_1 flag or MGDR. From satellite radiometer measurements of DMSP's SSM/I, sea ice concentration was extracted during the period from 1993 to 1996. To select a value of ice concentration, normally ranging from 0 to 100%, that can be used as a critical value of judging the existence for ice, sea ice areas estimated from various ice concentrations of radiometer measurements were correlated with the area estimated from the radar altimeter measurements. As a result, 20% of ice concentration was selected, and, then this value was used to integrate radiometer data with radar altimeter and ERS-1/2 scatterometer data. To indirectly verify the result, the last 20 year's sea ice concentration was correlated with surface temperature data near Esper-anza Observation Station. The two data showed a high correlation coefficient of 0.86. The amount of sea ice and temperature variation were found to be closely related in the study area, and this indirectly verifies the result of this study. We provided a method to judge the existence of sea ice from ice concentration of satellite radiometer data and suggested a method to monitor more detailed temporal and spatial variation of sea ice distribution by integra-tion of various microwave remote sensing techniques.