• Ocean and Polar Research
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• 제44권1호
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• pp.83-97
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• 2022

The Amundsen Sea in West Antarctica is one of the most affected regions by climate change, but it is one of the least studied realms due to difficulties in access. Korea Polar Research Institute (KOPRI) launched a research project in the Amundsen Sea in 2010 using the icebreaker research vessel (IBRV) Araon and has been conducting various research initiatives. In this paper, previous researches derived from the Amundsen Sea Embayment by Korean researchers are introduced. Through previous studies, researchers have been able to interpret the environmental and biogeochemical changes according to the inflow Circumpolar Deep Water (CDW) and provide information for climate models. In particular, researches using radiocarbon isotopes (¹⁴C) were introduced to understand the physical and biogeochemical mechanisms of the carbon cycle in the Amundsen Sea. Opportunely, with the construction of a second icebreaker research vessel, the direction for systematic and long-term polar data acquisition can be presented.

• Ocean and Polar Research
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• 제45권3호
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• pp.155-172
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• 2023

The collapse of ice shelves is a process that can severely increase the rise of global sea-levels through the reduction of the buttressing effect of ice shelves and the consequent acceleration of the ice flow of ice sheets. In recent years, the West Antarctic ice shelves in the Amundsen Sea, whose buttressing effect is essential for a great part of the West Antarctic ice sheet, have been experiencing the most rapid melting and thinning in the world. The melting of the West Antarctic ice shelves is caused primarily by heat transported by Circumpolar Deep Water (CDW). For this reason, it is important to investigate ice-ocean interactions that could influence the melting of ice shelves and evaluate the stability of West Antarctic ice shelves. A lot of researchers have been actively investigating the West Antarctic ice shelves in the Amundsen Sea. High-impact journals have recognized the importance of and published studies on ice-ocean interactions occurring near and under the ice shelves as well as the connections among ice shelves. However, in situ observations are limited due to extreme weather and sea-ice conditions near the ice shelves; therefore, many scientific questions remain unanswered. This study introduces the characteristics of the Amundsen Sea and investigate the past and latest research issues in this region. This study also gives suggestions regarding important scientific questions and directions for future research that should help early-career scientists take the lead in future research on the melting dynamics of the West Antarctic ice shelves in the Amundsen Sea.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권3호
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• pp.490-499
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• 2015

In this study, a local ice pressure prediction has been conducted by using measured data from two ice breaking tests that was conducted for a relatively big ice floe at Amundsen Sea in the Antarctica from January 31 to March 30 2012. The symmetry of load was considered by attaching strain gauges on the same sites inside the shell plating of ship at the port and the starboard sides in the bow thrust room. Using measured strain data, after the ice pressure was converted by the influence coefficient method and the direct method, the two values were found to be similar.

• 대한조선학회논문집
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• 제51권3호
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• pp.254-258
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• 2014

Field trial in ice-covered sea is one of the most important tasks in the design of icebreaking ships. To correctly estimate ice load and ice resistance on ship's hull, It is essential to understand the material properties of sea ice during ice field trials and to perform the proper experimental procedure by gathering sea ice data. A measurement of sea ice properties was conducted during February and March of 2012 with the Korean Icebreaking research vessel "ARAON" in the Amundsen Sea, Antarctica. This paper describes a test procedure to obtain sea ice data which provide basic information to estimate ice loads and icebreaking performance of the ship. The data gathered from sea ice field trials during the 2012 Antarctic voyage of the ARAON includes ice temperature/salinity/density and the compressive/flexural strength of sea ice. This paper analyses the gathered Antarctic sea ice material properties comparing with the previous data obtained during ARAON's Arctic and Antarctic voyages in 2010.

• Ocean and Polar Research
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• 제41권2호
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• pp.63-77
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• 2019

In order to investigate the behavior and seasonal variability of Mn as one of the bio-essential metals in the Amundsen sea, which is known as the most biologically productive coastal area around the Antartica, seawaters were collected using a clean sampling system for 10 stations (96 ea) in 2014 (ANA04B) and for 12 stations (139 ea) in 2016 (ANA06B) surveys of RV ARAON. Dissolved and particulate Mn concentration varied in the range of 0.15-4.43 nmol/kg and <0.01 to 2.42 nM in 2014 and in the range of 0.25-4.15 nmol/kg and 0.01-2.64 nM in 2016, respectively. From the sectional distribution of dissolved and particulate Mn, it might be suggested that dissolved/particulate Mn was provided from iceberg melting and diffusion/resuspension from sediments, respectively. Although this sea is highly productive, there was little evidence regarding the biological origin of dissolved Mn, but particulate Mn only in sea ice and offshore areas could be explained as originating from organic matters, e.g. phytoplanktons. And it could be suggested that the subsurface maximum of dissolved Mn was formed by isopycnal transport of melting materials from ice wall to offshore. Compared to early (2014) summer, temperature, salinity, biomass, dissolved and particulate Mn in late (2016) summer indicated that temporal variations might be resulted from the reduction of ice melting and mCDW flow, which induced a reduction in resuspension. In addition, in the late summer, particles including biomass were reduced, which brought about a reduction in the removal rate of dissolved Mn.

• Ocean and Polar Research
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• 제27권3호
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• pp.277-288
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• 2005

Spatial distribution and vertical structures of water masses around the Antarctic continental margin are described using synthesized hydrographic data. Antarctic Surface Water (AASW) over the shelf regime is distinguished from underlying other water masses by the cut-off salinity, varying from approximately 34.35 to 34.45 around Antarctica. Shelf water, characterized by salinity greater than the cut-off salinity and potential temperature less than $-17^{\circ}C$, is observed on the Ross Sea, off George V Land, off Wilkes Land, the Amery Basin, and the Weddell Sea, but in some shelves AASW occupies the entire shelf. Lower Circumpolar Deep Water is present everywhere around the Antarctic oceanic regime and in some places it mixes with Shelf Water, producing Antarctic Slope Front Water (ASFW). ASFW, characterized by potential temperature less than about $0^{\circ}C$ and greater than $-17^{\circ}C$, and salinity greater than the cut-off salinity, is found everywhere around Antarctica except in the Bellingshausen-Amundsen sector. The presence of different water masses over the Antarctic shelves and shelf edges produces mainly three types of water mass stratifications: no significant meridional property gradient in the Bellingshausen and Amundsen Seas, single property gradient where ASFW presents, and a V-shaped front where Shelf Water exists.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.414-417
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• 2008

We have extracted a surface deformation map of a part of Canisteo Peninsula on Amundsen Sea in West Antarctica by applying 4-pass DInSAR technique to two ERS-1/2 tandem pairs obtained on October 21-22, 1995 (diff-pair) and March 9-10, 1996 (topo-pair), and analyzed changes of glaciers, sea ice, ice shelves, and their kinematic interactions. We observed fast motion of glaciers pushing the adjoining sea ice. Some interferometric phases indicate the up-rise of sea ice of which type is thought to be land-fast ice to exert repulsive force against the pushing glacier. There were other glaciers and sea ice that moved to the same direction, suggesting that the sea ice in these regions was land-fast ice weakly harnessed to sea bottom or pack ice not harnessed at all. Several small circular fringes in ice shelves suggested that islands or seamounts on the bottom of ice shelves deterred the movement of ice shelves, resulting in the rise of ice surface.

• 한국제4기학회지
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• 제32권1_2호
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• pp.30-40
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• 2018

화석연료 사용 증가에 의해 북극은 다른 지역보다 온난화가 2-3배 빠르게 진행 중이며 이를 '북극 온난화 증폭'이라 한다 (Overland et al., 2017; Goose et al, 2018). 북극 온난화 증폭과 관련하여 북극 해빙은 급격히 줄고 있고, 그린랜드 빙하도 연안을 중심으로 빠르게 녹고 있다 (State of Climate, 2018). 그렇지만 남극은 기후변화의 양상이 북극과 다르게 나타나는데, 남극 반도와 서남극은 온난화가 빠르고 해빙과 육상 빙하의 감소도 두드러진데 반해 동남극은 온난화가 거의 없고 해빙과 육상빙하는 약간 증가 추세에 있다. 서남극과 동남극이 이와 같이 대조적으로 반응이 나타나는 원인은 아문젠해 저기압 강화(deepening)에 따른 시계방향의 순환 증가로 따뜻한 해양성 공기가 남극 반도와 서남극으로 유입되면서 서남극의 기온은 올라가는 경향을 보이는데 반해, 동남극은 차고 냉각된 남극 대륙의 공기가 로스해 쪽으로 불어나오며 수온을 낮추고 해빙을 확장시키는 역할을 한다. 또한 성층권 오존 농도 감소에 따라 남극 주변을 시계 방향으로 도는 제트기류가 강화됨에 따라 동남극은 약간의 냉각화가 나타나는 것으로 여겨진다. 본 연구에서는 최근 남극의 기후변화가 북극과 다르게 나타나는 현상을 살펴보고 가능한 이유를 고찰해 보고자 한다.

• 한국해양학회지:바다
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• 제19권2호
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• pp.109-124
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• 2014

남극 아문젠해의 탄소순환을 이해하기 위해서 표층에서 심층으로의 입자상 유기탄소 침강플럭스를 ${\psi}$/${\psi}$ 비평형법을 이용하여 추정하였다. 2012년 2월과 3월에 걸쳐 남극 아문젠해의 총 14개 정점에서 깊이별로 해수시료를 채취하였고, 총 ${\psi}$, 용존 ${\psi}$ 및 입자상 유기탄소를 분석하였다. 수심에 따라 총 ${\psi}$의 활동도 농도는 ${\psi}$에 비하여 결핍과 과잉을 나타내었다. 유광대에서 총 ${\psi}$의 결핍 정도는 엽록소 및 형광도와 거울상을 나타내고, 질산염 제거와 수반되어 나타나므로 생물 활동의 영향으로 파악되었다. 심층에서 일어나는 총 ${\psi}$ 결핍은 Fe/Mn 산화물에 의해 이루어지는 것으로 해석되었다. 유광대 바로 아래의 수층에서 나타나는 총 ${\psi}$ 과잉은 재광물화 작용보다는 이 깊이에 집적된 입자상 ${\psi}$에 기인하였다. 정상상태 모델로 추정한 ${\psi}$의 침강플럭스는 평균 $867{\pm}246dpmm^{-2}day^{-1}$이었으며, 유광대에서 질소와 인의 결핍 총량과 밀접한 관련성을 보였다. 입자상 유기탄소와 ${\psi}$의 비율($7.08{\pm}4.27{\mu}molCdpm^{-1}$)을 이용하여 추정한 입자상 유기탄소의 침강플럭스는 평균 $5.9{\pm}3.9mmolCm^{-2}day^{-1}$으로 나타났는데 이 값은 2-3월의 웨델해와 유사한 수준이었다. 입자상 유기탄소 플럭스와 일차생산력의 비율로 나타낸 생물 펌프의 효율(ThE)은 3-54%(평균 28%) 범위였다.

• 대한조선학회논문집
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• 제49권6호
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• pp.478-483
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• 2012

The speed performances of ice sea trial on the Arctic(2010 & 2011) area were shown different results depend on the ice floe size. Penetration phenomena of level ice was not happened on medium ice floe and tore up by the impact force because the mass of medium ice floe is similar to the mass of Araon which is Korean ice breaking research vessel and did not shut up by the ice ridge or iceberg. The sea trial on the Amundsen sea was performed at the big floe which is classified by WMO(World Meteorological Organization). Three measurements of ice properties and five results of speed trial were obtained with different ice thicknesses and engine powers. To evaluate speed of level ice trial and model test results at the same ice thickness and engine power, the correction method of HSVA(Hamburg Ship Model Basin) was used. The thickness, snow effect, flexural strength and friction coefficient were corrected to compare the speed of sea trial. The analyzed speed at 1.03m thickness of big floe was 5.85 knots at 10MW power and it's 6.10 knots at 1.0m ice thickness and the same power. It's bigger than the results of level ice because big floe was also slightly tore up by the impact force of vessel based on the observation of recorded video.