• Ocean and Polar Research
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• 제45권2호
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• pp.89-102
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• 2023

Climate and environmental changes in the Arctic Ocean due to global warming have been linked to extreme climate change in mid-latitude regions, including the Korean Peninsula, requiring a better understanding of the Arctic climate system based on the paleo-analog. This review introduces three paleoenvironmental research cases using neodymium isotopes (¹⁴³Nd/¹⁴⁴Nd, ε_Nd) measured on two different fractions of marine sediments: silicate-bound 'detrital' and Fe-Mn oxide-dominated 'authigenic' fractions. In the first case, detrital ε_Nd in core HH17-1085-GC on the continental shelf off northern Svalbard was used for tracing changes in sediment provenance and associated glacier behavior over the last 16.3 ka. The second case showed the potential use of authigenic ε_Nd as a quasi-conservative water mass tracer. Three prominent ε_Nd peaks and troughs observed in core PS72/410-1 from the Mendeleev Ridge in the western Arctic Ocean over the past 76 ka suggested episodic meltwater discharge events during 51~46, 39~35 and 21~13 ka BP. The last case proposed the use of the difference between authigenic and detrital ε_Nd as a proxy for reconstructing glacier fluctuation. The idea is based on the assumption that enhanced glacial erosion during glacier advances can supply sufficient freshly-exposed rock substrate for incongruent weathering, potentially leading to greater isotopic decoupling between bedrock and dissolved weathering products as recorded in detrital and authigenic ε_Nd, respectively. Thus, it would be worthwhile to take advantage of sedimentary ε_Nd to improve our understanding of past environmental changes in polar regions.

• 생명과학회지
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• 제30권11호
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• pp.931-938
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• 2020

TCTP는 다양한 진핵생물에서 풍부하게 존재하는 단백질 중에 하나이며, 암, 세포 증식, 유전자 조절 등과 관련된 세포의 생리학적 기작에서 중요한 역할을 담당하는 것으로 알려져 왔다. 더구나, TCTP는 dithiothreitol (DTT)나 hydrogen peroxide (H₂O₂)에 의해 유도되는 산화적 스트레스에 대한 저항성에 관여하는 중요한 단백질로 주목 받아 왔다. 한편, 극지역 서식 생물들은 강한 자외선에 의해 발생한 활성산소를 조절하기 위한 다양한 항산화 방어체계를 가지고 있다. 본 연구에서는 북극 동물플랑크톤 Calanus glacialis에서 분리된 TCTP가 산화적 스트레스 하에서 E. coli 세포의 저항성에 미치는 효과를 관찰하였다. C. glacialis에서 분리된 TCTP 유전자(ORF 522 bp) 서열을 분석하였고, 약 23 kDa의 재조합 단백질을 제작하였다. 관찰 결과, TCTP 재조합 단백질이 E. coli 세포에서 과발현 되었을 때, 세포들은 H₂O₂에 의해 유도된 산화적 스트레스에 대한 저항성이 증가하는 것을 확인하였다. 본 관찰을 통해, 북극 C. glacialis TCTP 단백질의 항산화 조절자로서의 역할에 대한 가능성을 처음으로 제시하였다.

• 한국지구과학회지
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• 제45권2호
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• pp.121-135
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• 2024

1991-2020년의 30년 동안 봄철(3-5월)에 북극-동아시아 지역의 지표면 부근 대기 온난화가 북극 진동에 따라 한국의 서울에서 발생하는 황사 사례일의 종관 기상 특성에 미치는 영향을 분석하였다. 북극-동아시아 지역의 봄철 온난화 증가는 한국의 서울에서 황사 사례일을 6일을 감소시켰고, 황사 사례일의 PM₁₀ 질량 농도도 -1.6 ㎍ m^-3yr^-1으로 강도를 약화시키는데 기여하고 있었다. 2010년대 한국에서 감소하고 있는 황사 사례일에 대한 동아시아 지역의 종관 기상 특성은 음(-)의 잠재소용돌이도(Potential Vorticity Unit; PVU)로 나타나는 고기압성 활동이 증가하고 있었다. 또한, 한국에서는 음(-)의 북극진동지수(Arctic Oscillation Index; AOI)에서 황사 사례일이 증가하고 양(+)에서는 감소하는 정적 편포를 보였다. AOI가 음(-)인 황사 사례일에서는 중국 대륙에 온난한 고기압이 강화되고 있었다. 더불어 한대 제트의 중심 위치가 북쪽으로 이동하면서 몽골과 중국 북부에서는 한대 기단의 남하에 의한 저기압성 활동이 약해지고 있었다. 황사의 발생이 감소하였을 뿐 아니라 발원지로부터 한국으로 황사를 수송하는 풍속이 감소하고 있었다. 반면, AOI가 양(+)인 황사 사례일에서는 중국 대륙에 광역적으로 온난하고 정체적인 고기압이 위치하고 있었으며, 한대 제트의 북쪽이 더욱 냉각되어 있었다. 몽골-중국 북부-한국에 이르는 지역에서 하층 대류권의 현저한 풍속 감소가 황사 발생을 감소시킬 뿐 아니라 장거리 수송을 약화시키는 원인이 되는 것으로 보인다.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2017년도 추계 학술발표초록집
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• pp.83-83
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• 2017

• 대한조선학회논문집
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• 제54권1호
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• pp.43-48
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• 2017

In recent years, the demand for ships and offshore platforms that can navigate and operate through the Arctic Ocean has been rapidly increasing due to global warming and large reservoirs of oil and natural gas in the area. Winterization design is one of the key issues to consider in the robust structural safety design and building of ships that operate in the Arctic and Sub-Arctic regions. However, international regulations for winterization design in Arctic condition regulated that only those ships and offshore platforms with a Polar Class designation and/or an alternative standard. In order to cope with the rising demand for operating in the Arctic region, existing and new Arctic vessels with a Polar Class designation are lacking to cover for adequate winterization design with HSE philosophy. Existing ships and offshore platform was not designed based on reliable data based on numerical and experiment studies. There are only designed as a performance and functional purposes. It is very important to obtain of reliable data and provide of design guidance of the anti-icing structures by taking the effects of low temperature into consideration. Therefore, the main objective of this paper reconsiders anti-icing design of aluminum helideck using the heating cable. To evaluate of reliable data and recommend of anti-icing design method, various types of analysis and methods can be applied in general. In the present study, finite element method carried out the thermal analysis with cold chamber testing for performance and capacity of heating cables.

• Water Engineering Research
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• 제4권1호
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• pp.31-43
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• 2003

The impacts of climate change on soil moisture in sub - Arctic watershed simulated by using the hydrologic model. A range of arbitrary changes in temperature and precipitation are applied to the runoff model to study the sensitivity of soil moisture due to potential changes in precipitation and temperature. The sensitivity analysis indicates that changes in precipitation are always amplified in soil moisture with the amplification factor for flow. The change in precipitation has effect on the soil moisture in the catchment. The percentage change in soil moisture levels can be greater than the percentage change in precipitation. Compared to precipitation, temperature increases or decreases alone have impacts on the soil moisture. These results show the potential for climate change to bring about soil moisture that may require a significant planning response. They are also indicative of the fact that hydrological impacts affecting water supply may be important in consider-ing the cost and benefits of potential climate change.

• Journal of Ship and Ocean Technology
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• 제12권1호
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• pp.35-44
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• 2008

As arctic energy resource is attracting public attention, arctic shipping market will also be growing in large as expected to increase in LNG trade from Arctic area to the western countries by shipping. During the voyages through such routes, collision with icebergs may be possible. In the present report, ice collision analyses are carried out from a practical point of view to verify the safety of hull structural strength of LNG carriers equipped with GTT $MKIII^{TM}$ membrane type cargo containment system. From the results of collision analyses and the operation-friendly design concept of no-repairing of cargo containment system, a safe operating envelope against ice collision is proposed for LNG carriers of membrane type cargo containment system. Based on the currently proposed safety criteria, it is concluded that LNG carriers with membrane tank type can operate safely with regard to the integrity of CCS in regions where collision between LNG carrier and iceberg is expected.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2019년도 하계 학술발표초록집
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• pp.246-246
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• 2019

• 대기
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• 제28권1호
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• pp.15-24
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• 2018

Sea ice plays an important role in modulating surface conditions at high and mid-latitudes. It reacts rapidly to climate change, therefore, it is a good indicator for capturing these changes from the Arctic climate. While many models have been used to study the predictability of climate variables, their performance in predicting sea ice was not well assessed. This study examines the predictability of the Arctic sea ice extent from ensemble prediction systems. The analysis is focused on verification of predictability in each model compared to the observation and prediction in particular, on lead time in Sub-seasonal to Seasonal (S2S) scales. The S2S database now provides quasi-real time ensemble forecasts and hindcasts up to about 60 days from 11 centers: BoM, CMA, ECCC, ECMWF, HMCR, ISAC-CNR, JMA, KMA, Meteo France, NCEP and UKMO. For multi model comparison, only models coupled with sea ice model were selected. Predictability is quantified by the climatology, bias, trends and correlation skill score computed from hindcasts over the period 1999 to 2009. Most of models are able to reproduce characteristics of the sea ice, but they have bias with seasonal dependence and lead time. All models show decreasing sea ice extent trends with a maximum magnitude in warm season. The Arctic sea ice extent can be skillfully predicted up 6 weeks ahead in S2S scales. But trend-independent skill is small and statistically significant for lead time over 6 weeks only in summer.

• 대한조선학회논문집
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• 제51권2호
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• pp.107-113
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• 2014

The icebreaking research vessel, ARAON had her second ice trial in the Arctic Sea from 16th July to 12th August 2010. During the voyage, the local ice loads acting on the bow of port side were measured from 14 strain gauges. The measurements were also carried out in ice waters with various ice concentration ratio as well as the icebreaking performance tests. In this study, the ice loads measured during the 'general' operation in ice waters were analyzed. As a first step, the relationship between the location of strain gauges and the ice loads were investigated, and then the possibility for observation of higher ice loads was estimated based on the probability density function. The relationship between the ship speed and the ice load was also investigated. 718 peak stresses data higher than 20 MPa obtained from strain gauges array attached in longitudinally and vertically was analyzed. In general, the ice load increases as the ship speed increases in the low ship speed range, and ice load decreases as the ship speed is greater than a certain speed.