• 제목/요약/키워드: the Arctic

검색결과 484건 처리시간 0.027초

Improved Arctic Ocean Oxygen Isotope Stratigraphy Results from the Yermak Plateau (ODP Leg 151 : Site 910A)

  • 남승일
    • 한국제4기학회:학술대회논문집
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    • 한국제4기학회 2004년도 하계학술대회
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    • pp.51-51
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    • 2004
  • As an important contribution to the planed drilling (IODP) in the central part of the Arctic Ocean, we are currently working on a refined chronostratigraphy for Marine Isotope Stage (MIS) 16 to MIS 2 on the exciting material from ODP Site 910A (Leg 151) which has been recovered from the marginal Eastern Arctic Ocean (the Yermak Plateau - the Atlantic/Arctic Ocean Gateway). Several stratigraphic age fix-points support the interpretation of the stable oxygen. isotope record of planktonic foraminifer N, pachyderma sin. that is punctuated by several short-term meltwater events. We believe that our new record will serve as 'the important correlating tool for establishing a basic stratigraphy for the Quaternary Arctic Ocean as well as for generating high-resolution paleoenvironmental reconstructions in the central Arctic Ocean. Furthermore, our study will provide reference stratigraphic data sets for interpreting the micropaleontological, sedimentological and organic / inorganic - geochemical proxies of the new boreholes that will be drilled on the Lomonosov Ridge(Central Arctic Ocean) in the frame of the "Arctic Coring Expedition' (ACEX, IODP) in summer 2004.

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북극의 기후변화로 인한 생태계변화의 경제적 가치추정 (Economic Valuation of the Biodiversity-Related Changes in Ecosystem Services of the Arctic Caused by Climate Change)

  • 강희찬;김효선
    • 자원ㆍ환경경제연구
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    • 제25권2호
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    • pp.321-349
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    • 2016
  • 2015년은 기후관측이 시작된 이래 평균기온이 최고치를 기록한 해이다. 특히 북극은 어느 지역보다도 빠른 속도로 온난화가 진행되고 있어, 빙하가 계속 감소추세에 있다. 이러한 북극의 급격한 기후변화는 해수면의 상승은 물론 북극의 생태계 균형까지 위협할 뿐만 아니라 한국을 비롯한 중위도권 겨울한파의 원인으로 지목되고 있다. 생물다양성은 기후변화-생태시스템의 복잡한 상호관계를 함축적으로 나타내는 생태학적 개념으로, 본 논문에서는 이를 북극에 적용하여 북극이 보유하고 있는 생물다양성에 대한 경제적 가치를 대한민국 시민을 대상으로 조건부가치추정 방식을 시도하였다. 분석 결과, 북극 생물다양성 개선을 통해 대한민국 시민이 얻는 총 편익은 최소 연간 3,186억 원에서 최대 7,159억 원 정도인 것으로 추정되었다. 본 연구는 생물다양성에 대한 속성을 세부적으로 분류하는데 의도가 있는 것이 아니라 기후변화에 따라 훼손될 우려가 있는 북극의 생태계 전반에 대한 가치평가에 그 목적이 있다. 따라서 북극이 제공하는 생태서비스와 생물다양성을 각기 다른 속성으로 구분할 경우 그 경제적 가치는 본 연구에서 제시하는 편익과 상이할 수 있다.

IDENTIFICATION OF THERMODYNAMIC PARAMETERS OF ARCTIC SEA ICE AND NUMERICAL SIMULATION

  • Xiw, Chao;Feng, Enmin;Li, Zhijun;Peng, Lu
    • Journal of applied mathematics & informatics
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    • 제26권3_4호
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    • pp.519-530
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    • 2008
  • This paper studies the multi-domain coupled system of one dimensional Arctic temperature field and establishes identification model about the thermodynamic parameters of sea ice (heat storage capacity, density and conductivity) by the so-called output least-square estimate according to the temperature data acquired by a monitor buoy installed in the Arctic ocean. By the optimal control theory, the existence and dependability of weak solution and the identifiability of identification model have been given. Moreover, necessary optimality condition is proposed. Furthermore, the optimal algorithm for the identification model is constructed. By using the optimal thermodynamic parameters of Arctic sea ice, the numerical simulation is implemented, and the numerical results of temperature distribution of Arctic sea ice are demonstrated.

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STRONG PRESERVERS OF SYMMETRIC ARCTIC RANK OF NONNEGATIVE REAL MATRICES

  • Beasley, LeRoy B.;Encinas, Luis Hernandez;Song, Seok-Zun
    • 대한수학회지
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    • 제56권6호
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    • pp.1503-1514
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    • 2019
  • A rank 1 matrix has a factorization as $uv^t$ for vectors u and v of some orders. The arctic rank of a rank 1 matrix is the half number of nonzero entries in u and v. A matrix of rank k can be expressed as the sum of k rank 1 matrices, a rank 1 decomposition. The arctic rank of a matrix A of rank k is the minimum of the sums of arctic ranks of the rank 1 matrices over all rank 1 decomposition of A. In this paper we obtain characterizations of the linear operators that strongly preserve the symmetric arctic ranks of symmetric matrices over nonnegative reals.

북극 온난화 증폭이 겨울철 동아시아 한파 발생에 미치는 영향 고찰 (Review on the impact of Arctic Amplification on winter cold surges over east Asia)

  • 김성중;김정훈;전상윤;김맹기;이솔지
    • 한국제4기학회지
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    • 제33권1_2호
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    • pp.1-23
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    • 2021
  • 산업화 이후 대기 이산화탄소를 포함한 온실가스 증가에 따라 전지구 기온이 빠르게 올라가고 있는데, 특히 북극의 온난화가 저위도에 비해 2-3배 빠르다. 그리고 온난화와 함께 북극 해빙의 농도와 면적도 지속적으로 감소추세에 있다. 이는 온난화에 대한 북극의 눈과 얼음에 의한 알베도 피드백, 표면기온 차이에 의해 더 많은 에너지를 잃는 플랑크 피드백, 저위도와 고위도의 안정도 차이에 의한 기온감률 피드백, 북극해 온난화에 의한 구름과 수증기 증가 피드백, 그리고 북극으로의 현열속 증가 등에 의한다. 이와 같이 급격한 북극 온난화에 반해 중위도에는 냉각화가 나타나고, 지역에 따라 한파가 더 자주 나타나고 오래 지속되는 경향을 보이는데, 이는 북극 온난화 증폭과 연관 있다는 연구결과들이 많이 보고되고 있다. 북극 온난화는 2가지 경로를 통해 중위도 냉각화로 연결되는데, 하나는 종관규모로 주로 블로킹과 로스비 파동의 발달에 의한 시베리아 고기압을 강화시켜 대류권에서 일어나는 현상이며, 두 번째는 북극 온난화에 의한 상층으로의 행성파 전달을 활성화하여 폴라보텍스를 약화시켜 성층권을 경유해 수개월 동안 나타나는 경로이다. 중위도 한파와 북극 온난화 증폭 간에는 수주에서 수개월의 시차가 존재하기 때문에, 북극 온난화부터 중위도 한파에 이르는 일련의 연쇄 과정을 이해할 수 있으면 겨울철 중위도 기상 예측의 정확성을 높일 수 있다. 이연구에서는 기존에 보고된 많은 결과들을 종합하고 온도와 해빙 변화 경향 분석을 통해 현재 진행되는 북극 온난화와 중위도 냉각화 경향 그리고 이 둘 간의 관계를 고찰해 보고자 한다.

북극항로를 운항하기 위한 선결과제 (Some Items to be Resolved for Going through the Arctic Route)

  • 남청도;김정만
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2010년도 추계학술대회
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    • pp.137-138
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    • 2010
  • 최근 지구온난화 영향 등으로 인하여 북극해의 해빙이 가속화 되고 있어 북극항로의 상용화가 예상보다 빨라질 전망이다. 하절기 북극해의 얼음 면적은 1979년 위성관측이 개시된 이래 약 40%정도로 줄었다. 북극항로가 상업적으로 이용되기 위해서는 경제성 문제 이전에 북극항로 중 일부가 특정국가 배타적으로 사용하는 문제가 해결되어야 하며, 다음으로 선박운항 기술적 요인으로서 부빙들이 움직이고 있는 기후조건에 맞는 특수선박의 건조가 필요하며 또한 이들 선박을 북극해에서 운항할 수 있는 선원들의 교육 프로그램의 이수 외에도 관련 연안국과의 협력으로 국제적인 공인이 이루어져야 할 것이다. 그 밖에 북극항로 정보시스템개발에 대해서도 연구가 이루어져야 할 것이다.

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구조적 안전성을 고려한 빙해선박의 안전 운항속도 평가 (Safe Speed Estimation of Arctic Ships considering Structural Safety)

  • 노인식;임승재;강국진
    • 대한조선학회논문집
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    • 제55권3호
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    • pp.236-242
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    • 2018
  • Damage due to ice collision is the most serious threat for the structural safety of ships operating in arctic region. Since such hull damages are usually caused by the collision of floating ice at excessive voyage speed of ships, the authorities responsible for the shipping at arctic sea are required to provide the speed limit for safe voyage, so-called safe speed. In countries near arctic ocean, such as Canada and Russia, empirical methods to determine the safe speed of ships based on their long experience of arctic voyage have been established and applied them in the real arctic navigation. However, in Korea, it is not easy to accumulate the arctic voyage experience and related technical database, so it seems to be a realistic approach to adopt a safe voyage speed estimating method in arctic sea based on the ice collision simulation technology using the nonlinear finite element analysis. The aim of this study is to develop a technique for estimating the safe voyage speed of vessels operating at arctic sea through the ice collision analysis, In order to achieve this goal, the standard procedure of the ice collision analysis is dealt with and example analysis was carried out and the results were considered. To investigate the validity of developed method, POLARIS system proposed by IMO was studied for comparison.

우리나라 겨울철 기온과 북반구 대기 순환과의 상관성 분석 (Analysis on the Relationship between the Korean Temperature and the Atmospheric Circulation over the Northern Hemisphere during Winter)

  • 임소민;예상욱;김공래
    • 대기
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    • 제22권2호
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    • pp.187-197
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    • 2012
  • This study investigates the relationship between the Korean temperature and the atmospheric circulation such as Arctic Oscillation, Siberian High and Aleutian Low during the winter (December-January) for the period of 1970-2011. It is found that all indices to represent aforementioned circulations are significantly correlated with Korean winter temperature for the period of 1970 - 2011. There are marked contrasts in such relationship, however, before and after the mid-1980s when a significant regime shift of Korean winter temperature occurred. While Korean winter temperature has a close relationship with Arctic Oscillation after the mid-1980s, its relationship with Siberian High and Aleutian Low is weakened. The composite analysis between a positive and negative phase of Arctic Oscillation before and after the mid-1980s is conducted to examine a recent strengthening of Arctic Oscillation-Korean winter temperature relationship. It is found that the structural changes of low-level wind and the geopotential height at 500 hPa between the two phases of Arctic Oscillation are more effective to influence Korean winter temperature after the mid-1980s. This may induce a close relationship between the Korean winter temperature variability and Arctic Oscillation after the mid-1980s compared to before the mid-1980s.

Reviews on Natural Resources in the Arctic: Petroleum, Gas, Gas Hydrates and Minerals

  • Yoon, Jong-Ryeol;Kim, Yea-Dong
    • Ocean and Polar Research
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    • 제23권1호
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    • pp.51-62
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    • 2001
  • The Arctic consists of numerous sedimentary basins containing voluminous natural resources and two of the world's major oil and gas producing areas. The western Siberia Basin in the Arctic region has the largest petroliferous province with an area of 800 ${\times}$ 1,200 km and produces more than 60% of total Russian oil production. The North Slope of Alaska produces about 20% of the U.S. output, i.e., 11% of the total U.S. consumption. Being small compared to those regions, the Canadian Northwest Territories and the Pechora Basin in Russia produce only fair amount of oil and natural gas. There are also many promising areas in the northern continental shelf of Russia. In addition to Russia, Svalbard and Greenland have been investigated for oil and gas. Gas hydrates are widespread in both permafrost regions and arctic continental shelf areas. The reserves of gas hydrates in the Arctic Ocean are about 20${\sim}$32% of total estimated amounts of gas hydrates in the world ocean. Mineral mining is well developed, especially in Russia. The major centers are located around the Kuznetsk Basin and Noril'sk. They are major suppliers of gold, tin, nickel, copper, platinum, cobalt, iron ore, coal as well as apatite. There are also some minings of lead-zinc in Alaska and Arctic Canada.

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Simulation of optimal arctic routes using a numerical sea ice model based on an ice-coupled ocean circulation method

  • Nam, Jong-Ho;Park, Inha;Lee, Ho Jin;Kwon, Mi Ok;Choi, Kyungsik;Seo, Young-Kyo
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제5권2호
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    • pp.210-226
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    • 2013
  • Ever since the Arctic region has opened its mysterious passage to mankind, continuous attempts to take advantage of its fastest route across the region has been made. The Arctic region is still covered by thick ice and thus finding a feasible navigating route is essential for an economical voyage. To find the optimal route, it is necessary to establish an efficient transit model that enables us to simulate every possible route in advance. In this work, an enhanced algorithm to determine the optimal route in the Arctic region is introduced. A transit model based on the simulated sea ice and environmental data numerically modeled in the Arctic is developed. By integrating the simulated data into a transit model, further applications such as route simulation, cost estimation or hindcast can be easily performed. An interactive simulation system that determines the optimal Arctic route using the transit model is developed. The simulation of optimal routes is carried out and the validity of the results is discussed.